.course-main,
.knowledge-main {
  --course-surface: var(--ui-surface, rgba(255, 255, 255, 0.82));
  --course-surface-solid: var(--ui-surface-raised, #ffffff);
  --course-surface-soft: var(--ui-surface-soft, #f1f6f5);
  --course-line: var(--ui-line, rgba(7, 9, 11, 0.1));
  --course-line-strong: var(--ui-line-strong, rgba(7, 9, 11, 0.16));
  --course-accent: var(--ui-accent, #278898);
  --course-accent-soft: #e3f1ef;
  --course-primary: #063641;
  --course-tag-surface: #f8f3e9;
  --course-tag-text: #5d5342;
  --course-neutral-surface: #f0f2f4;
  --course-neutral-text: #5b6269;
  --course-warning-surface: #fff1cf;
  --course-warning-text: #7a4e00;
  --course-backdrop: rgba(7, 9, 11, 0.42);
  color-scheme: light;
}

body.theme-light.course-page,
body.theme-light.knowledge-page {
  --bbs-shell-page: #f4f6f8;
  --bbs-shell-line: #dde3e8;
  --bbs-shell-text: #07090b;
  --bbs-shell-muted: rgba(7, 9, 11, 0.58);
}

body.theme-dark.course-page,
body.theme-dark.knowledge-page {
  --bbs-shell-page: #091317;
  --bbs-shell-line: rgba(236, 246, 246, 0.14);
  --bbs-shell-text: #f0f6f5;
  --bbs-shell-muted: rgba(240, 246, 245, 0.64);
}

body.theme-dark .course-main,
body.theme-dark .knowledge-main {
  --course-surface: var(--ui-surface, rgba(17, 31, 37, 0.9));
  --course-surface-solid: var(--ui-surface-raised, #111f25);
  --course-surface-soft: var(--ui-surface-soft, #16282e);
  --course-line: var(--ui-line, rgba(236, 246, 246, 0.13));
  --course-line-strong: var(--ui-line-strong, rgba(236, 246, 246, 0.22));
  --course-accent: var(--ui-accent, #78d9c6);
  --course-accent-soft: rgba(120, 217, 198, 0.14);
  --course-primary: #278898;
  --course-tag-surface: rgba(229, 201, 109, 0.12);
  --course-tag-text: #eadbaf;
  --course-neutral-surface: rgba(240, 246, 245, 0.08);
  --course-neutral-text: rgba(240, 246, 245, 0.72);
  --course-warning-surface: rgba(229, 201, 109, 0.14);
  --course-warning-text: #f0d887;
  --course-backdrop: rgba(1, 8, 11, 0.7);
  color-scheme: dark;
}

/* Database-backed course knowledge maps */
.course-map-main {
  --map-node-width: 230px;
  --map-node-height: 112px;
  --map-bg: #edf5f3;
  --map-bg-deep: #e5efed;
  --map-grid: rgba(7, 74, 81, 0.055);
  --map-grid-major: rgba(7, 74, 81, 0.09);
  --map-ambient-a: rgba(39, 136, 152, 0.14);
  --map-ambient-b: rgba(120, 217, 198, 0.16);
  --map-card: rgba(255, 255, 255, 0.82);
  --map-card-hover: rgba(255, 255, 255, 0.96);
  --map-card-border: rgba(7, 74, 81, 0.17);
  --map-card-border-active: rgba(19, 137, 145, 0.56);
  --map-text: #0b343a;
  --map-muted: rgba(11, 52, 58, 0.58);
  --map-beacon: #158f96;
  --map-signal-start: #278898;
  --map-signal-middle: #27a99e;
  --map-signal-end: #0d7989;
  --map-related: rgba(22, 110, 122, 0.54);
  --map-learning: #cc8a20;
  --map-learning-soft: rgba(224, 167, 55, 0.18);
  --map-shadow: 0 16px 34px rgba(18, 67, 72, 0.12);
}

body.theme-dark .course-map-main,
body.course-map-editor-page .course-map-main {
  --map-bg: #061216;
  --map-bg-deep: #041014;
  --map-grid: rgba(129, 226, 218, 0.045);
  --map-grid-major: rgba(129, 226, 218, 0.075);
  --map-ambient-a: rgba(41, 142, 143, 0.18);
  --map-ambient-b: rgba(32, 90, 104, 0.18);
  --map-card: rgba(8, 30, 35, 0.82);
  --map-card-hover: rgba(10, 42, 47, 0.94);
  --map-card-border: rgba(130, 235, 226, 0.2);
  --map-card-border-active: rgba(153, 255, 246, 0.64);
  --map-text: #edfffc;
  --map-muted: rgba(185, 235, 229, 0.58);
  --map-beacon: #73e2d8;
  --map-signal-start: #4cbfc2;
  --map-signal-middle: #8cf0dc;
  --map-signal-end: #52c6d7;
  --map-related: rgba(116, 210, 205, 0.5);
  --map-learning: #f2cb72;
  --map-learning-soft: rgba(242, 203, 114, 0.16);
  --map-shadow: 0 18px 42px rgba(0, 8, 12, 0.3);
}

body.course-page:has(.course-map-immersive) {
  overflow: hidden;
  background: var(--bbs-shell-page);
}

body.course-page:has(.course-map-immersive) > .page-shell {
  min-height: 100dvh;
  padding: 0 !important;
  background: var(--bbs-shell-page) !important;
}

body.course-page:has(.course-map-immersive) .topbar,
body.course-page:has(.course-map-immersive) .mobile-nav,
body.course-page:has(.course-map-immersive) .site-footer {
  display: none !important;
}

html body.course-page:has(.course-map-immersive) > .page-shell,
html body.knowledge-page:has(.course-material-immersive) > .page-shell,
html body.course-page.course-map-editor-page > .page-shell {
  padding: 0 !important;
}

html body.course-page:has(.course-map-immersive) .topbar,
html body.course-page:has(.course-map-immersive) .mobile-nav,
html body.course-page:has(.course-map-immersive) .site-footer,
html body.knowledge-page:has(.course-material-immersive) .topbar,
html body.knowledge-page:has(.course-material-immersive) .mobile-nav,
html body.knowledge-page:has(.course-material-immersive) .site-footer,
html body.course-page.course-map-editor-page .topbar,
html body.course-page.course-map-editor-page .mobile-nav,
html body.course-page.course-map-editor-page .site-footer {
  display: none !important;
}

.course-map-immersive {
  position: fixed;
  inset: 0;
  z-index: 200;
  width: 100vw;
  height: 100dvh;
  padding: 0;
  background: var(--bbs-shell-page);
}

.course-map-immersive .course-map-panel {
  width: 100%;
  height: 100%;
  min-height: 0;
  border: 0;
  border-radius: 0;
}

.course-map-immersive .course-map-scroller {
  width: 100%;
  height: 100dvh;
  min-height: 0;
}

.course-map-reader-controls {
  position: fixed;
  top: max(16px, env(safe-area-inset-top));
  left: max(16px, env(safe-area-inset-left));
  z-index: 220;
  display: flex;
  gap: 8px;
}

.course-map-reader-hud {
  position: fixed;
  top: max(16px, env(safe-area-inset-top));
  right: max(16px, env(safe-area-inset-right));
  z-index: 220;
  width: min(286px, calc(100vw - 92px));
  display: grid;
  gap: 4px;
  padding: 13px 15px 12px;
  border: 1px solid var(--course-line-strong);
  border-radius: 14px;
  background: color-mix(in srgb, var(--course-surface-solid) 88%, transparent);
  box-shadow: 0 14px 38px rgba(7, 9, 11, 0.12);
  backdrop-filter: blur(18px);
  -webkit-backdrop-filter: blur(18px);
}

.course-map-reader-hud > p {
  display: flex;
  align-items: center;
  gap: 7px;
  margin: 0;
  color: var(--course-accent);
  font-family: var(--font-ui);
  font-size: 0.62rem;
  font-weight: 900;
  letter-spacing: 0.17em;
  text-transform: uppercase;
}

.course-map-reader-hud > p span {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--course-accent);
  box-shadow: 0 0 0 4px color-mix(in srgb, var(--course-accent) 13%, transparent);
}

.course-map-reader-hud > strong {
  overflow: hidden;
  color: var(--bbs-shell-text);
  font-size: 1rem;
  line-height: 1.35;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.course-map-reader-hud > small {
  color: var(--bbs-shell-muted);
  font-size: 0.7rem;
}

.course-map-reader-legend {
  display: flex;
  align-items: center;
  gap: 13px;
  margin-top: 6px;
  padding-top: 8px;
  border-top: 1px solid var(--course-line);
}

.course-map-reader-legend span {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  color: var(--bbs-shell-muted);
  font-size: 0.66rem;
  font-weight: 700;
}

.course-map-reader-legend i {
  width: 20px;
  height: 0;
  border-top: 2px solid var(--course-accent);
}

.course-map-reader-legend i.is-related {
  border-top-style: dashed;
  opacity: 0.68;
}

.course-map-reader-legend i.is-learning {
  width: 8px;
  height: 8px;
  border: 0;
  border-radius: 50%;
  background: var(--map-learning);
  box-shadow:
    0 0 0 4px var(--map-learning-soft),
    0 0 12px var(--map-learning);
}

.course-map-reader-control {
  width: 44px;
  height: 44px;
  display: grid;
  place-items: center;
  border: 1px solid var(--course-line-strong);
  border-radius: 50%;
  background: color-mix(in srgb, var(--course-surface-solid) 88%, transparent);
  color: var(--bbs-shell-text) !important;
  font-family: var(--font-ui);
  font-size: 1.2rem;
  font-weight: 900;
  box-shadow: 0 10px 28px rgba(7, 9, 11, 0.12);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
}

button.course-map-reader-control {
  padding: 0;
  cursor: pointer;
}

.course-map-reader-control:hover,
.course-map-reader-control:focus-visible {
  border-color: var(--course-accent);
  outline: none;
  color: var(--course-accent) !important;
  transform: translateY(-2px);
}

body.knowledge-page:has(.course-material-immersive) {
  overflow-x: hidden;
  background: var(--bbs-shell-page);
}

body.knowledge-page:has(.course-material-immersive) > .page-shell {
  min-height: 100dvh;
  padding: 0 !important;
  background: var(--bbs-shell-page) !important;
}

body.knowledge-page:has(.course-material-immersive) .topbar,
body.knowledge-page:has(.course-material-immersive) .mobile-nav,
body.knowledge-page:has(.course-material-immersive) .site-footer {
  display: none !important;
}

.course-material-immersive {
  position: relative;
  z-index: 200;
  width: 100%;
  min-height: 100dvh;
  padding: clamp(54px, 8vw, 112px) 24px 34px;
  background: var(--bbs-shell-page);
}

.course-material-back {
  position: fixed;
  top: max(16px, env(safe-area-inset-top));
  left: max(16px, env(safe-area-inset-left));
  z-index: 220;
  width: auto;
  min-width: 44px;
  grid-auto-flow: column;
  gap: 7px;
  padding: 0 13px;
  border-radius: 999px;
  font-size: 1rem;
}

.course-material-back strong {
  font-size: 0.7rem;
  font-weight: 850;
  letter-spacing: 0.02em;
}

.course-material-reader {
  width: min(100%, 860px);
  display: grid;
  gap: 36px;
  margin: 0 auto;
}

.course-material-header {
  padding-bottom: 32px;
  border-bottom: 1px solid var(--course-line);
}

.course-material-header h1 {
  margin: 0;
  color: var(--bbs-shell-text);
  font-family: 'Hiragino Sans GB', 'PingFang SC', 'Microsoft YaHei', 'Noto Serif SC', sans-serif;
  font-size: clamp(2.5rem, 8vw, 5.4rem);
  font-weight: 900;
  line-height: 1.04;
}

.course-material-header > p:last-child {
  max-width: 720px;
  margin: 16px 0 0;
  color: var(--bbs-shell-muted);
  font-size: 1.02rem;
  line-height: 1.8;
}

.course-material-body {
  min-height: 52vh;
  color: var(--bbs-shell-text);
  font-size: 1.02rem;
  line-height: 1.9;
}

.course-material-body > :first-child {
  margin-top: 0;
}

.course-material-body > h1:first-child {
  display: none;
}

@media (max-width: 680px) {
  .course-material-immersive {
    padding: 88px 18px 22px;
  }

  .course-material-reader {
    gap: 26px;
  }
}

.course-map-actions {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  flex-wrap: wrap;
  gap: 10px;
}

.course-map-actions a,
.course-map-actions button,
.course-map-edit-link {
  min-height: 44px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 0 16px;
  border: 1px solid var(--course-line-strong);
  border-radius: 8px;
  background: var(--course-primary);
  color: #ffffff !important;
  font-family: var(--font-ui);
  font-size: 0.88rem;
  font-weight: 900;
  cursor: pointer;
}

.course-map-edit-link {
  background: var(--course-surface-solid) !important;
  color: var(--bbs-shell-text) !important;
}

.course-map-stats {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: 8px;
}

.course-map-stats span {
  min-height: 38px;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 0 12px;
  border: 1px solid var(--course-line);
  border-radius: 999px;
  background: var(--course-surface-soft);
  color: var(--bbs-shell-muted);
  font-size: 0.8rem;
}

.course-map-stats strong {
  color: var(--course-accent);
  font-family: var(--font-ui);
  font-size: 1rem;
}

.course-map-toolbar {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 18px;
  padding: 14px 18px;
  border: 1px solid var(--course-line);
  border-radius: 8px;
  background: var(--course-surface);
}

.course-map-toolbar p {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin: 0;
  color: var(--bbs-shell-muted);
  font-size: 0.82rem;
  font-weight: 800;
}

.course-map-toolbar .course-map-hint {
  margin-left: auto;
  font-weight: 500;
}

.course-map-legend {
  width: 34px;
  height: 0;
  border-top: 2px solid var(--course-accent);
}

.course-map-legend.is-ordered::after {
  content: '';
  display: block;
  width: 7px;
  height: 7px;
  margin: -5px 0 0 auto;
  border-top: 2px solid var(--course-accent);
  border-right: 2px solid var(--course-accent);
  transform: rotate(45deg);
}

.course-map-legend.is-related {
  border-top-style: dashed;
  opacity: 0.72;
}

.course-map-panel {
  position: relative;
  min-height: 640px;
  overflow: hidden;
  border: 1px solid var(--course-line);
  border-radius: 8px;
  background: var(--map-bg);
}

.course-map-panel.is-editor {
  min-width: 0;
}

.course-map-scroller {
  width: 100%;
  height: min(72vh, 760px);
  min-height: 620px;
  overflow: auto;
  overscroll-behavior: contain;
  scrollbar-color: color-mix(in srgb, var(--course-accent) 28%, transparent) transparent;
  scrollbar-width: thin;
}

.course-map-scroller::-webkit-scrollbar {
  width: 8px;
  height: 8px;
}

.course-map-scroller::-webkit-scrollbar-thumb {
  border: 2px solid transparent;
  border-radius: 999px;
  background: color-mix(in srgb, var(--course-accent) 32%, transparent);
  background-clip: padding-box;
}

.course-map-scroller.is-reader-fit {
  overflow: hidden;
}

.course-map-canvas {
  position: relative;
  min-width: 100%;
  min-height: 100%;
  isolation: isolate;
  overflow: hidden;
  background:
    radial-gradient(circle at 22% 18%, var(--map-ambient-a), transparent 30%),
    radial-gradient(circle at 78% 72%, var(--map-ambient-b), transparent 34%),
    linear-gradient(145deg, var(--map-bg), var(--map-bg-deep));
}

.course-map-background {
  position: absolute;
  inset: 0;
  z-index: 0;
  background-image: var(--course-map-background-image);
  background-position: center;
  background-size: cover;
  opacity: 0;
  transform: scale(1.01);
  transition: opacity 280ms ease;
}

.course-map-canvas.has-custom-background .course-map-background {
  opacity: 0.78;
}

.course-map-canvas.has-custom-background::after {
  content: '';
  position: absolute;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  background:
    linear-gradient(
      color-mix(in srgb, var(--map-bg) 62%, transparent),
      color-mix(in srgb, var(--map-bg-deep) 72%, transparent)
    ),
    radial-gradient(circle at center, transparent 18%, var(--map-bg-deep) 120%);
}

.course-map-grid {
  position: absolute;
  inset: 0;
  z-index: 1;
  background-image:
    linear-gradient(to right, var(--map-grid-major) 1px, transparent 1px),
    linear-gradient(to bottom, var(--map-grid-major) 1px, transparent 1px),
    linear-gradient(to right, var(--map-grid) 1px, transparent 1px),
    linear-gradient(to bottom, var(--map-grid) 1px, transparent 1px),
    radial-gradient(circle, var(--map-grid-major) 1px, transparent 1.5px);
  background-size:
    200px 200px,
    200px 200px,
    40px 40px,
    40px 40px,
    20px 20px;
  opacity: 0.74;
  mask-image: radial-gradient(circle at center, #000 25%, rgba(0, 0, 0, 0.74) 76%, transparent);
  pointer-events: none;
}

.course-map-edges {
  position: absolute;
  inset: 0;
  z-index: 2;
  overflow: visible;
  pointer-events: none;
}

.course-map-edge {
  fill: none;
  stroke: url('#course-map-signal-gradient');
  stroke-linecap: round;
  stroke-width: 2;
  filter: drop-shadow(0 0 4px color-mix(in srgb, var(--map-beacon) 42%, transparent));
  vector-effect: non-scaling-stroke;
}

.course-map-edge-halo {
  fill: none;
  stroke: var(--map-signal-middle);
  stroke-linecap: round;
  stroke-width: 9;
  opacity: 0.08;
  vector-effect: non-scaling-stroke;
}

.course-map-edge-halo.is-related {
  stroke-width: 5;
  opacity: 0.05;
}

.course-map-edge.is-related {
  stroke: var(--map-related);
  stroke-dasharray: 6 9;
  stroke-width: 1.6;
  opacity: 0.72;
}

.course-map-edge-pulse {
  fill: none;
  stroke: var(--map-signal-middle);
  stroke-dasharray: 0.035 0.965;
  stroke-dashoffset: 0;
  stroke-linecap: round;
  stroke-width: 5;
  opacity: 0.84;
  filter: drop-shadow(0 0 5px var(--map-beacon));
  vector-effect: non-scaling-stroke;
  animation: course-map-signal-travel 4.2s linear infinite;
  animation-delay: var(--edge-delay);
}

.course-map-gradient-start {
  stop-color: var(--map-signal-start);
}

.course-map-gradient-middle {
  stop-color: var(--map-signal-middle);
}

.course-map-gradient-end {
  stop-color: var(--map-signal-end);
}

#course-map-arrow path,
#course-map-reader-arrow path {
  fill: var(--map-signal-end);
}

@keyframes course-map-signal-travel {
  to {
    stroke-dashoffset: -1;
  }
}

/* Reader chapter overview */
.course-map-directory-layout {
  position: relative;
  z-index: 3;
  width: min(1500px, 100%);
  min-height: 100dvh;
  display: grid;
  grid-template-columns: clamp(220px, 19vw, 286px) minmax(0, 1fr);
  align-items: start;
  gap: clamp(18px, 2vw, 30px);
  margin: 0 auto;
  padding: 138px clamp(28px, 4vw, 68px) 86px;
}

.course-map-index-sidebar {
  min-width: 0;
  overflow: hidden;
  border: 1px solid color-mix(in srgb, var(--map-card-border) 86%, transparent);
  border-radius: 22px;
  background: color-mix(in srgb, var(--map-card) 86%, transparent);
  box-shadow:
    inset 0 1px 0 color-mix(in srgb, #fff 42%, transparent),
    0 24px 64px color-mix(in srgb, var(--map-text) 8%, transparent);
  backdrop-filter: blur(18px);
  -webkit-backdrop-filter: blur(18px);
}

.course-map-index-heading {
  display: grid;
  gap: 4px;
  padding: 17px 17px 14px;
  border-bottom: 1px solid color-mix(in srgb, var(--map-card-border) 64%, transparent);
}

.course-map-index-heading small,
.course-map-directory-heading small,
.course-map-directory-current-copy > small,
.course-map-directory-section-heading small {
  color: var(--map-beacon);
  font-family: 'SFMono-Regular', Consolas, monospace;
  font-size: 0.58rem;
  font-weight: 900;
  letter-spacing: 0.14em;
}

.course-map-index-heading strong {
  color: var(--map-text);
  font-size: 1rem;
}

.course-map-index-heading span {
  color: var(--map-muted);
  font-size: 0.64rem;
}

.course-map-index-list {
  display: grid;
  gap: 3px;
  padding: 7px;
}

.course-map-index-item {
  position: relative;
  width: 100%;
  min-height: 56px;
  display: grid;
  grid-template-columns: 32px minmax(0, 1fr) 14px;
  align-items: center;
  gap: 9px;
  padding: 7px 9px;
  border: 1px solid transparent;
  border-radius: 13px;
  background: transparent;
  color: var(--map-text);
  text-align: left;
  cursor: pointer;
  transition:
    border-color 160ms ease,
    background 160ms ease,
    transform 160ms ease;
}

.course-map-index-item:hover,
.course-map-index-item:focus-visible {
  border-color: color-mix(in srgb, var(--map-beacon) 24%, transparent);
  background: color-mix(in srgb, var(--map-beacon) 6%, transparent);
  outline: none;
  transform: translateX(2px);
}

.course-map-index-item.is-active {
  border-color: color-mix(in srgb, var(--map-beacon) 42%, transparent);
  background: color-mix(in srgb, var(--map-beacon) 11%, transparent);
  box-shadow: inset 3px 0 0 var(--map-beacon);
}

.course-map-index-item.has-learning-node:not(.is-active)::after {
  content: '';
  position: absolute;
  top: 8px;
  right: 8px;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--map-learning);
  box-shadow: 0 0 10px var(--map-learning);
}

.course-map-index-number {
  width: 30px;
  height: 30px;
  display: grid;
  place-items: center;
  border: 1px solid color-mix(in srgb, var(--map-card-border-active) 66%, transparent);
  border-radius: 10px;
  color: var(--map-muted);
  font-family: 'SFMono-Regular', Consolas, monospace;
  font-size: 0.62rem;
  font-weight: 900;
}

.course-map-index-item.is-active .course-map-index-number {
  border-color: color-mix(in srgb, var(--map-beacon) 60%, transparent);
  background: color-mix(in srgb, var(--map-beacon) 12%, transparent);
  color: var(--map-beacon);
}

.course-map-index-copy {
  min-width: 0;
  display: grid;
  gap: 2px;
}

.course-map-index-copy small {
  color: var(--map-muted);
  font-family: 'SFMono-Regular', Consolas, monospace;
  font-size: 0.5rem;
  font-weight: 800;
  letter-spacing: 0.08em;
}

.course-map-index-copy strong,
.course-map-index-copy span {
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.course-map-index-copy strong {
  font-size: 0.72rem;
  line-height: 1.22;
}

.course-map-index-copy span {
  color: var(--map-muted);
  font-size: 0.54rem;
}

.course-map-index-item > i {
  color: var(--map-muted);
  font-size: 1.05rem;
  font-style: normal;
  transition: transform 160ms ease;
}

.course-map-index-item.is-active > i {
  color: var(--map-beacon);
  transform: translateX(2px);
}

.course-map-directory-panel {
  min-width: 0;
  overflow: hidden;
  border: 1px solid color-mix(in srgb, var(--map-card-border-active) 62%, transparent);
  border-radius: 28px;
  background: color-mix(in srgb, var(--map-card) 42%, transparent);
  box-shadow:
    inset 0 1px 0 color-mix(in srgb, #fff 48%, transparent),
    0 30px 82px color-mix(in srgb, var(--map-beacon) 10%, transparent);
}

.course-map-directory-heading {
  min-height: 84px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  padding: 18px 24px;
  border-bottom: 1px solid color-mix(in srgb, var(--map-card-border) 62%, transparent);
}

.course-map-directory-heading > span {
  min-width: 0;
  display: grid;
  grid-template-columns: auto auto;
  align-items: baseline;
  gap: 4px 10px;
}

.course-map-directory-heading strong {
  grid-column: 1;
  overflow: hidden;
  color: var(--map-text);
  font-size: clamp(1.18rem, 1.9vw, 1.72rem);
  text-overflow: ellipsis;
  white-space: nowrap;
}

.course-map-directory-heading i,
.course-map-directory-heading p,
.course-map-directory-section-heading i {
  color: var(--map-muted);
  font-size: 0.66rem;
  font-style: normal;
}

.course-map-directory-heading p {
  flex: 0 0 auto;
  margin: 0;
}

.course-map-directory-current {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  align-items: end;
  gap: 28px;
  margin: 20px 20px 0;
  padding: clamp(22px, 3vw, 38px);
  overflow: hidden;
  border: 1px solid color-mix(in srgb, var(--map-beacon) 35%, transparent);
  border-radius: 22px;
  background:
    radial-gradient(
      circle at 90% 16%,
      color-mix(in srgb, var(--map-beacon) 18%, transparent),
      transparent 34%
    ),
    color-mix(in srgb, var(--map-bg) 86%, transparent);
}

.course-map-directory-current::before {
  content: '';
  position: absolute;
  top: -58px;
  right: -26px;
  width: 180px;
  height: 180px;
  border: 1px solid color-mix(in srgb, var(--map-beacon) 18%, transparent);
  border-radius: 50%;
  box-shadow:
    0 0 0 30px color-mix(in srgb, var(--map-beacon) 3%, transparent),
    0 0 0 62px color-mix(in srgb, var(--map-beacon) 2%, transparent);
  pointer-events: none;
}

.course-map-directory-current.is-learning {
  border-color: color-mix(in srgb, var(--map-learning) 52%, transparent);
  background:
    radial-gradient(
      circle at 90% 16%,
      color-mix(in srgb, var(--map-learning) 18%, transparent),
      transparent 34%
    ),
    color-mix(in srgb, var(--map-bg) 86%, transparent);
}

.course-map-directory-current.is-learning::before {
  border-color: color-mix(in srgb, var(--map-learning) 22%, transparent);
  box-shadow:
    0 0 0 30px color-mix(in srgb, var(--map-learning) 3%, transparent),
    0 0 0 62px color-mix(in srgb, var(--map-learning) 2%, transparent);
}

.course-map-directory-current-copy {
  position: relative;
  z-index: 1;
  min-width: 0;
}

.course-map-directory-current.is-learning .course-map-directory-current-copy > small {
  color: var(--map-learning);
}

.course-map-directory-current-copy > span {
  display: block;
  margin-top: 14px;
  color: var(--map-muted);
  font-family: 'SFMono-Regular', Consolas, monospace;
  font-size: 0.68rem;
  font-weight: 900;
  letter-spacing: 0.08em;
}

.course-map-directory-current-copy h2 {
  max-width: 760px;
  margin: 6px 0 0;
  color: var(--map-text);
  font-size: clamp(1.55rem, 3.2vw, 2.65rem);
  line-height: 1.14;
}

.course-map-directory-current-copy p {
  max-width: 720px;
  margin: 13px 0 0;
  color: var(--map-muted);
  font-size: 0.78rem;
  line-height: 1.7;
}

.course-map-directory-current-copy > div {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 4px 8px;
  margin-top: 17px;
  color: var(--map-muted);
  font-size: 0.65rem;
}

.course-map-directory-current-copy > div b {
  color: var(--map-text);
  font-family: 'SFMono-Regular', Consolas, monospace;
  font-size: 0.92rem;
}

.course-map-directory-current-copy > div i {
  margin-left: 6px;
  color: var(--map-learning);
  font-style: normal;
}

.course-map-directory-current-actions {
  position: relative;
  z-index: 1;
  min-width: 132px;
  display: grid;
  gap: 8px;
}

.course-map-directory-current-actions button,
.course-map-directory-current-actions a {
  min-height: 38px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0 14px;
  border: 1px solid color-mix(in srgb, var(--map-beacon) 44%, transparent);
  border-radius: 999px;
  background: color-mix(in srgb, var(--map-beacon) 12%, transparent);
  color: var(--map-text);
  font-size: 0.66rem;
  font-weight: 900;
  text-decoration: none;
  cursor: pointer;
}

.course-map-directory-current-actions a {
  border-color: color-mix(in srgb, var(--map-card-border) 82%, transparent);
  background: color-mix(in srgb, var(--map-card) 78%, transparent);
  color: var(--map-muted);
}

.course-map-directory-current-actions button:hover,
.course-map-directory-current-actions button:focus-visible,
.course-map-directory-current-actions a:hover,
.course-map-directory-current-actions a:focus-visible {
  border-color: var(--map-beacon);
  color: var(--map-text);
  outline: none;
}

.course-map-directory-section-heading {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 16px;
  padding: 24px 22px 12px;
}

.course-map-directory-section-heading > span {
  display: grid;
  gap: 3px;
}

.course-map-directory-section-heading strong {
  color: var(--map-text);
  font-size: 0.9rem;
}

.course-map-directory-nodes {
  display: grid;
  grid-template-columns: repeat(3, minmax(180px, 1fr));
  gap: 10px;
  padding: 0 20px 22px;
}

.course-map-directory-nodes .course-map-topic,
.course-map-directory-nodes .course-map-topic-main {
  min-height: 88px;
}

.course-map-directory-nodes .course-map-topic-main {
  gap: 5px;
  padding-top: 11px;
  padding-bottom: 11px;
}

.course-map-chapter-grid {
  position: relative;
  z-index: 3;
  width: min(1500px, 100%);
  min-height: 100dvh;
  display: grid;
  grid-template-columns: repeat(3, minmax(260px, 1fr));
  grid-auto-flow: row dense;
  align-content: start;
  align-items: start;
  gap: clamp(24px, 3vw, 48px) clamp(20px, 2.7vw, 44px);
  margin: 0 auto;
  padding: 154px clamp(32px, 6vw, 92px) 120px;
}

.course-map-focus-workspace {
  position: relative;
  z-index: 3;
  width: min(1500px, 100%);
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 34px;
  margin: 0 auto;
  padding: 154px clamp(32px, 6vw, 92px) 36px;
}

.course-map-focused-chapter,
.course-map-cross-relations {
  min-width: 0;
}

.course-map-focused-chapter {
  --chapter-accent: var(--map-beacon);
  position: relative;
  overflow: hidden;
  border: 1px solid color-mix(in srgb, var(--map-card-border-active) 72%, transparent);
  border-radius: 28px;
  background: color-mix(in srgb, var(--map-card) 36%, transparent);
  box-shadow:
    inset 0 1px 0 color-mix(in srgb, #fff 46%, transparent),
    0 30px 82px color-mix(in srgb, var(--map-beacon) 13%, transparent);
}

.course-map-focused-chapter.has-learning-node {
  --chapter-accent: var(--map-learning);
}

.course-map-focused-heading {
  display: grid;
  grid-template-columns: 52px minmax(0, 1fr) auto;
  align-items: center;
  gap: 15px;
  padding: 20px 310px 16px 22px;
  border-bottom: 1px solid color-mix(in srgb, var(--map-card-border) 58%, transparent);
}

.course-map-focused-heading > button,
.course-map-focus-summary button {
  padding: 8px 11px;
  border: 1px solid color-mix(in srgb, var(--chapter-accent) 28%, transparent);
  border-radius: 999px;
  background: color-mix(in srgb, var(--chapter-accent) 8%, transparent);
  color: var(--map-muted);
  font-size: 0.66rem;
  font-weight: 800;
  cursor: pointer;
}

.course-map-focused-heading > button:hover,
.course-map-focused-heading > button:focus-visible,
.course-map-focus-summary button:hover,
.course-map-focus-summary button:focus-visible {
  border-color: var(--chapter-accent);
  color: var(--map-text);
  outline: none;
}

.course-map-focus-stage {
  display: grid;
  grid-template-columns: minmax(190px, 1fr) minmax(230px, 280px) minmax(190px, 1fr);
  align-items: center;
  gap: clamp(24px, 4vw, 64px);
  min-height: 360px;
  padding: 30px clamp(24px, 4vw, 64px);
}

.course-map-focus-side {
  display: grid;
  align-content: center;
  gap: 12px;
}

.course-map-focus-direction {
  color: var(--map-muted);
  font-family: 'SFMono-Regular', Consolas, monospace;
  font-size: 0.58rem;
  font-weight: 900;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.course-map-focus-side.is-left {
  justify-items: end;
}

.course-map-focus-side.is-left .course-map-focus-direction {
  text-align: right;
}

.course-map-focus-side.is-right {
  justify-items: start;
}

.course-map-focus-side .course-map-topic {
  width: min(100%, 290px);
}

.course-map-focus-center {
  display: grid;
  justify-items: stretch;
  gap: 9px;
  text-align: center;
}

.course-map-focus-center > small {
  color: var(--map-beacon);
  font-family: 'SFMono-Regular', Consolas, monospace;
  font-size: 0.6rem;
  font-weight: 900;
  letter-spacing: 0.14em;
  text-transform: uppercase;
}

.course-map-focus-center > span {
  color: var(--map-muted);
  font-size: 0.62rem;
}

.course-map-focus-center .course-map-topic {
  width: 100%;
  min-height: 116px;
}

.course-map-focus-center .course-map-topic-main {
  min-height: 114px;
}

.course-map-focus-summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 13px 22px 18px;
}

.course-map-focus-summary span {
  color: var(--map-muted);
  font-size: 0.7rem;
}

.course-map-cross-relations {
  display: grid;
  gap: 14px;
}

.course-map-cross-relations.is-incoming {
  padding-bottom: 4px;
}

.course-map-cross-relations.is-outgoing {
  padding-top: 4px;
}

.course-map-cross-relations.is-incoming .course-map-chapter-card {
  --chapter-accent: var(--map-signal-start);
}

.course-map-cross-relations.is-outgoing .course-map-chapter-card {
  --chapter-accent: var(--map-signal-end);
}

.course-map-cross-relations > header {
  display: grid;
  gap: 4px;
  padding: 0 4px 4px;
  text-align: center;
}

.course-map-cross-relations > header small {
  color: var(--map-signal-middle);
  font-family: 'SFMono-Regular', Consolas, monospace;
  font-size: 0.6rem;
  font-weight: 900;
  letter-spacing: 0.14em;
}

.course-map-cross-relations > header strong {
  color: var(--map-text);
  font-size: 1.05rem;
}

.course-map-cross-relations > header span {
  color: var(--map-muted);
  font-size: 0.7rem;
}

.course-map-cross-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  align-items: start;
  gap: 18px;
}

.course-map-chapter-grid.is-focus-rest {
  min-height: 0;
  grid-template-columns: repeat(4, minmax(220px, 1fr));
  gap: 22px;
  padding-top: 36px;
}

.course-map-chapter-grid.is-focus-rest::before {
  content: '其他章节';
  grid-column: 1 / -1;
  padding-bottom: 2px;
  color: var(--map-muted);
  font-size: 0.7rem;
  font-weight: 800;
  letter-spacing: 0.12em;
}

.course-map-chapter-card {
  --chapter-accent: var(--map-beacon);
  position: relative;
  min-width: 0;
  overflow: visible;
  border: 1px solid color-mix(in srgb, var(--map-card-border) 88%, transparent);
  border-radius: 24px;
  background: color-mix(in srgb, var(--map-card) 88%, transparent);
  box-shadow:
    inset 0 1px 0 color-mix(in srgb, #fff 46%, transparent),
    0 24px 60px color-mix(in srgb, var(--map-text) 9%, transparent);
  backdrop-filter: blur(19px);
  -webkit-backdrop-filter: blur(19px);
  transition:
    border-color 220ms ease,
    box-shadow 220ms ease,
    transform 260ms ease;
}

.course-map-chapter-card::before {
  content: '';
  position: absolute;
  top: -1px;
  right: 34px;
  left: 34px;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--chapter-accent), transparent);
  opacity: 0.66;
}

.course-map-chapter-card.is-collapsed {
  min-height: 146px;
  transform: translate(var(--chapter-drift-x), var(--chapter-drift-y));
}

.course-map-chapter-card.is-collapsed:hover,
.course-map-chapter-card.is-collapsed:focus-within {
  border-color: var(--map-card-border-active);
  box-shadow:
    inset 0 1px 0 color-mix(in srgb, #fff 50%, transparent),
    0 28px 68px color-mix(in srgb, var(--map-beacon) 17%, transparent);
  transform: translate(var(--chapter-drift-x), calc(var(--chapter-drift-y) - 5px));
}

.course-map-chapter-card.is-expanded {
  grid-column: span 2;
  border-color: color-mix(in srgb, var(--map-card-border-active) 72%, transparent);
  background: color-mix(in srgb, var(--map-card) 36%, transparent);
  box-shadow:
    inset 0 1px 0 color-mix(in srgb, #fff 52%, transparent),
    0 30px 82px color-mix(in srgb, var(--map-beacon) 13%, transparent);
  backdrop-filter: none;
  -webkit-backdrop-filter: none;
}

.course-map-chapter-card.is-preview {
  overflow: hidden;
  border-color: color-mix(in srgb, var(--map-signal-middle) 68%, transparent);
  background: color-mix(in srgb, var(--map-card) 54%, transparent);
  box-shadow:
    inset 0 1px 0 color-mix(in srgb, #fff 42%, transparent),
    0 22px 54px color-mix(in srgb, var(--map-beacon) 13%, transparent);
  backdrop-filter: none;
  -webkit-backdrop-filter: none;
}

.course-map-chapter-card.has-learning-node {
  --chapter-accent: var(--map-learning);
  border-color: color-mix(in srgb, var(--map-learning) 54%, var(--map-card-border));
}

.course-map-chapter-toggle {
  width: 100%;
  min-height: 144px;
  display: grid;
  grid-template-columns: 58px minmax(0, 1fr) auto;
  align-items: center;
  gap: 15px;
  padding: 23px 24px;
  border: 0;
  border-radius: inherit;
  background: transparent;
  color: var(--map-text);
  text-align: left;
  cursor: pointer;
}

.course-map-chapter-card.is-expanded .course-map-chapter-toggle {
  min-height: 112px;
  border-radius: 24px 24px 0 0;
}

.course-map-chapter-card.is-preview .course-map-chapter-toggle {
  min-height: 88px;
  grid-template-columns: 38px minmax(0, 1fr) auto;
  gap: 9px;
  padding: 12px 14px;
  border-radius: 24px 24px 0 0;
}

.course-map-chapter-card.is-preview .course-map-chapter-orbit {
  width: 36px;
  height: 36px;
}

.course-map-chapter-card.is-preview .course-map-chapter-copy {
  gap: 3px;
}

.course-map-chapter-card.is-preview .course-map-chapter-copy strong {
  font-size: 0.88rem;
}

.course-map-chapter-card.is-preview .course-map-chapter-action {
  max-width: 58px;
  font-size: 0.58rem;
  text-align: right;
}

.course-map-chapter-card.is-preview .course-map-chapter-action i {
  transform: none;
}

.course-map-chapter-toggle:focus-visible {
  outline: 2px solid var(--chapter-accent);
  outline-offset: -5px;
}

.course-map-chapter-orbit {
  position: relative;
  width: 52px;
  height: 52px;
  display: grid;
  place-items: center;
  border: 1px solid color-mix(in srgb, var(--chapter-accent) 36%, transparent);
  border-radius: 50%;
  background: radial-gradient(
    circle,
    color-mix(in srgb, var(--chapter-accent) 16%, transparent),
    transparent 60%
  );
}

.course-map-chapter-orbit::before,
.course-map-chapter-orbit::after {
  content: '';
  position: absolute;
  border: 1px solid color-mix(in srgb, var(--chapter-accent) 28%, transparent);
  border-radius: 50%;
}

.course-map-chapter-orbit::before {
  inset: 7px -4px;
  transform: rotate(32deg);
}

.course-map-chapter-orbit::after {
  inset: -4px 9px;
  transform: rotate(-28deg);
}

.course-map-chapter-orbit i {
  width: 11px;
  height: 11px;
  border-radius: 50%;
  background: var(--chapter-accent);
  box-shadow:
    0 0 0 6px color-mix(in srgb, var(--chapter-accent) 11%, transparent),
    0 0 18px color-mix(in srgb, var(--chapter-accent) 70%, transparent);
}

.course-map-chapter-copy {
  min-width: 0;
  display: grid;
  gap: 5px;
}

.course-map-chapter-copy small {
  color: var(--chapter-accent);
  font-family: 'SFMono-Regular', Consolas, monospace;
  font-size: 0.62rem;
  font-weight: 800;
  letter-spacing: 0.14em;
  text-transform: uppercase;
}

.course-map-chapter-copy strong {
  overflow: hidden;
  color: var(--map-text);
  font-size: clamp(1rem, 1.3vw, 1.22rem);
  line-height: 1.28;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.course-map-chapter-copy > span {
  overflow: hidden;
  color: var(--map-muted);
  font-size: 0.72rem;
  line-height: 1.4;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.course-map-chapter-action {
  display: grid;
  justify-items: end;
  gap: 6px;
  color: var(--map-muted);
  font-size: 0.66rem;
  font-weight: 800;
}

.course-map-chapter-action i {
  width: 26px;
  height: 26px;
  display: grid;
  place-items: center;
  border: 1px solid color-mix(in srgb, var(--chapter-accent) 24%, transparent);
  border-radius: 50%;
  color: var(--chapter-accent);
  font-size: 1rem;
  font-style: normal;
  transition: transform 220ms ease;
}

.course-map-chapter-card.is-expanded .course-map-chapter-action i {
  transform: rotate(180deg);
}

.course-map-chapter-nodes {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(188px, 1fr));
  gap: 12px;
  padding: 0 20px 22px;
}

.course-map-preview-context {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  margin: 0 12px 7px;
  padding: 6px 8px;
  border: 1px solid color-mix(in srgb, var(--map-signal-middle) 18%, transparent);
  border-radius: 11px;
  background: color-mix(in srgb, var(--map-signal-middle) 6%, transparent);
}

.course-map-preview-context span {
  min-width: 0;
  overflow: hidden;
  color: var(--map-muted);
  font-size: 0.62rem;
  font-weight: 700;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.course-map-preview-context span i {
  width: 6px;
  height: 6px;
  display: inline-block;
  margin-right: 6px;
  border-radius: 50%;
  background: var(--map-signal-middle);
  box-shadow: 0 0 8px var(--map-signal-middle);
}

.course-map-preview-context button {
  flex: 0 0 auto;
  padding: 3px 7px;
  border: 0;
  border-radius: 999px;
  background: color-mix(in srgb, var(--map-card) 72%, transparent);
  color: var(--map-muted);
  font-size: 0.58rem;
  font-weight: 800;
  cursor: pointer;
}

.course-map-preview-context button:hover,
.course-map-preview-context button:focus-visible {
  color: var(--map-text);
  outline: 1px solid var(--map-card-border-active);
}

.course-map-chapter-nodes.is-preview-list {
  grid-template-columns: minmax(0, 1fr);
  gap: 7px;
  padding: 0 12px 12px;
}

.course-map-chapter-nodes.is-preview-list .course-map-topic,
.course-map-chapter-nodes.is-preview-list .course-map-topic-main {
  min-height: 72px;
}

.course-map-chapter-nodes.is-preview-list .course-map-topic-main {
  gap: 4px;
  padding: 9px 34px 9px 11px;
}

.course-map-chapter-nodes.is-preview-list .course-map-topic-meta {
  display: none;
}

.course-map-chapter-nodes.is-preview-list .course-map-topic-detail {
  top: 8px;
  right: 8px;
}

.course-map-topic {
  position: relative;
  min-width: 0;
  min-height: 98px;
  border: 1px solid color-mix(in srgb, var(--map-card-border) 85%, transparent);
  border-radius: 16px;
  background: color-mix(in srgb, var(--map-bg) 92%, transparent);
  box-shadow: inset 0 1px 0 color-mix(in srgb, #fff 35%, transparent);
  transition:
    border-color 180ms ease,
    box-shadow 180ms ease,
    opacity 180ms ease,
    transform 180ms ease;
}

.course-map-topic:hover,
.course-map-topic:focus-within {
  border-color: var(--map-card-border-active);
  background: color-mix(in srgb, var(--map-card-hover) 96%, transparent);
  transform: translateY(-2px);
}

.course-map-topic-main {
  width: 100%;
  min-height: 96px;
  display: grid;
  align-content: center;
  gap: 7px;
  padding: 14px 39px 14px 15px;
  border: 0;
  border-radius: inherit;
  background: transparent;
  color: var(--map-text);
  text-align: left;
  cursor: pointer;
}

.course-map-topic-main:focus-visible {
  outline: 2px solid var(--map-beacon);
  outline-offset: -4px;
}

.course-map-topic-code {
  color: var(--map-muted);
  font-family: 'SFMono-Regular', Consolas, monospace;
  font-size: 0.58rem;
  font-weight: 800;
  letter-spacing: 0.09em;
}

.course-map-topic-main strong {
  display: -webkit-box;
  overflow: hidden;
  color: var(--map-text);
  font-size: 0.83rem;
  line-height: 1.38;
  -webkit-box-orient: vertical;
  -webkit-line-clamp: 2;
}

.course-map-topic-meta {
  min-height: 17px;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px;
}

.course-map-topic-meta b,
.course-map-topic-meta i {
  color: var(--map-muted);
  font-size: 0.59rem;
  font-style: normal;
  font-weight: 700;
}

.course-map-topic-meta b {
  padding: 2px 6px;
  border-radius: 999px;
  background: var(--map-learning-soft);
  color: var(--map-learning);
}

.course-map-topic-detail {
  position: absolute;
  top: 11px;
  right: 11px;
  width: 25px;
  height: 25px;
  display: grid;
  place-items: center;
  border: 1px solid color-mix(in srgb, var(--map-card-border) 80%, transparent);
  border-radius: 50%;
  background: color-mix(in srgb, var(--map-card) 82%, transparent);
  color: var(--map-muted) !important;
  font-size: 0.72rem;
  font-weight: 900;
  opacity: 0.62;
  transition:
    opacity 160ms ease,
    color 160ms ease,
    transform 160ms ease;
}

.course-map-topic:hover .course-map-topic-detail,
.course-map-topic-detail:focus-visible {
  color: var(--map-beacon) !important;
  opacity: 1;
  outline: none;
  transform: translate(1px, -1px);
}

.course-map-topic.is-focused {
  border-color: var(--map-beacon);
  background: color-mix(in srgb, var(--map-beacon) 13%, var(--map-card));
  box-shadow:
    inset 0 1px 0 color-mix(in srgb, #fff 44%, transparent),
    0 0 0 3px color-mix(in srgb, var(--map-beacon) 11%, transparent),
    0 14px 32px color-mix(in srgb, var(--map-beacon) 18%, transparent);
}

.course-map-topic.is-focused .course-map-topic-code,
.course-map-topic.is-focused .course-map-topic-meta i {
  color: var(--map-beacon);
}

.course-map-topic.is-neighbor {
  border-color: color-mix(in srgb, var(--map-signal-middle) 64%, transparent);
  box-shadow: inset 3px 0 0 color-mix(in srgb, var(--map-signal-middle) 72%, transparent);
}

.course-map-topic.is-dimmed {
  opacity: 0.4;
  filter: saturate(0.55);
}

.course-map-topic.is-learning::before {
  content: '';
  position: absolute;
  inset: -4px;
  z-index: 2;
  border: 1px solid color-mix(in srgb, var(--map-learning) 66%, transparent);
  border-radius: 19px;
  box-shadow: 0 0 22px var(--map-learning-soft);
  pointer-events: none;
  animation: course-map-learning-pulse 2.8s ease-in-out infinite;
}

.course-map-topic.is-learning .course-map-topic-code {
  color: var(--map-learning);
}

.course-map-reader-edges {
  z-index: 2;
  opacity: 0.94;
}

.course-map-reader-edges .course-map-edge {
  stroke-width: 2.1;
}

.course-map-reader-edges .course-map-edge-halo {
  stroke-width: 8;
  opacity: 0.08;
}

.course-map-reader-edges .course-map-edge-pulse {
  stroke-width: 3.5;
  opacity: 0.72;
}

@keyframes course-map-learning-pulse {
  0%,
  100% {
    opacity: 0.48;
    transform: scale(0.99);
  }

  50% {
    opacity: 1;
    transform: scale(1.025);
  }
}

.course-map-node {
  position: absolute;
  z-index: 3;
  width: var(--map-node-width);
  height: var(--map-node-height);
  display: block;
  padding: 0;
  overflow: visible;
  border: 0;
  background: transparent;
  color: var(--map-text);
  cursor: pointer;
  touch-action: none;
  transform: translate(-50%, -100%);
  transition:
    filter 180ms ease,
    opacity 180ms ease;
}

.course-map-node:hover,
.course-map-node:focus-visible,
.course-map-node.is-selected {
  z-index: 5;
  filter: brightness(1.04);
  outline: none;
}

.course-map-node:focus-visible .course-map-beacon,
.course-map-node.is-selected .course-map-beacon {
  box-shadow:
    0 0 0 5px color-mix(in srgb, var(--map-beacon) 15%, transparent),
    0 0 0 9px color-mix(in srgb, var(--map-beacon) 7%, transparent),
    0 0 18px 5px color-mix(in srgb, var(--map-beacon) 42%, transparent);
}

.course-map-node.is-dragging {
  z-index: 6;
  cursor: grabbing;
  filter: brightness(1.28);
}

.course-map-node.is-edge-source {
  z-index: 5;
}

.course-map-node.is-edge-source .course-map-beacon::after {
  animation-duration: 1.1s;
  border-color: var(--map-beacon);
}

.course-map-hologram {
  position: absolute;
  left: 50%;
  bottom: 25px;
  width: min(222px, calc(100% - 8px));
  min-height: 64px;
  display: grid;
  grid-template-columns: 32px minmax(0, 1fr) 20px;
  align-items: center;
  gap: 8px;
  padding: 10px 11px;
  overflow: hidden;
  border: 1px solid var(--map-card-border);
  border-radius: 13px;
  background: var(--map-card);
  box-shadow:
    inset 0 1px 0 color-mix(in srgb, #ffffff 42%, transparent),
    var(--map-shadow);
  pointer-events: none;
  transform: translateX(-50%);
  transform-origin: center bottom;
  transition:
    border-color 180ms ease,
    background 180ms ease,
    box-shadow 180ms ease,
    transform 180ms ease;
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
}

.course-map-hologram::before {
  content: '';
  position: absolute;
  top: 0;
  right: 18px;
  left: 18px;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--map-signal-middle), transparent);
  opacity: 0.76;
}

.course-map-node:hover .course-map-hologram,
.course-map-node:focus-visible .course-map-hologram,
.course-map-node.is-selected .course-map-hologram {
  border-color: var(--map-card-border-active);
  background: var(--map-card-hover);
  box-shadow:
    inset 0 1px 0 color-mix(in srgb, #ffffff 48%, transparent),
    0 20px 44px color-mix(in srgb, var(--map-beacon) 18%, transparent);
  transform: translateX(-50%) translateY(-4px);
}

.course-map-node-index {
  width: 32px;
  height: 32px;
  display: grid;
  place-items: center;
  border: 1px solid color-mix(in srgb, var(--map-beacon) 24%, transparent);
  border-radius: 10px;
  background: color-mix(in srgb, var(--map-beacon) 9%, transparent);
  color: var(--map-signal-end);
  font-family: 'SFMono-Regular', Consolas, monospace;
  font-size: 0.7rem;
  font-weight: 900;
}

.course-map-node-copy {
  min-width: 0;
  display: grid;
  gap: 3px;
}

.course-map-node-id {
  display: flex;
  align-items: center;
  gap: 5px;
  color: var(--map-muted);
  font-family: 'SFMono-Regular', Consolas, monospace;
  font-size: 0.58rem;
  font-weight: 700;
  letter-spacing: 0.11em;
}

.course-map-node-id::before {
  content: '';
  width: 5px;
  height: 5px;
  flex: 0 0 auto;
  border-radius: 50%;
  background: var(--map-muted);
}

.course-map-node.has-document .course-map-node-id::before {
  background: var(--map-beacon);
  box-shadow: 0 0 7px color-mix(in srgb, var(--map-beacon) 58%, transparent);
}

.course-map-node strong {
  width: 100%;
  overflow: hidden;
  color: var(--map-text);
  font-family: 'PingFang SC', 'Microsoft YaHei', sans-serif;
  font-size: 0.82rem;
  font-weight: 800;
  line-height: 1.25;
  text-align: left;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.course-map-node-arrow {
  width: 20px;
  height: 20px;
  display: grid;
  place-items: center;
  border-radius: 50%;
  color: var(--map-muted);
  font-size: 0.82rem;
  transition:
    background 180ms ease,
    color 180ms ease,
    transform 180ms ease;
}

.course-map-node:hover .course-map-node-arrow,
.course-map-node:focus-visible .course-map-node-arrow,
.course-map-node.is-selected .course-map-node-arrow {
  background: color-mix(in srgb, var(--map-beacon) 11%, transparent);
  color: var(--map-beacon);
  transform: translate(1px, -1px);
}

.course-map-beacon {
  position: absolute;
  left: 50%;
  bottom: 0;
  width: 18px;
  height: 18px;
  display: grid;
  place-items: center;
  border: 1px solid color-mix(in srgb, var(--map-beacon) 62%, transparent);
  border-radius: 50%;
  background: color-mix(in srgb, var(--map-beacon) 14%, var(--map-bg));
  box-shadow:
    0 0 0 4px color-mix(in srgb, var(--map-beacon) 9%, transparent),
    0 0 15px 4px color-mix(in srgb, var(--map-beacon) 31%, transparent);
  transform: translateX(-50%);
  transition: box-shadow 180ms ease;
}

.course-map-beacon > span {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--map-beacon);
  box-shadow: 0 0 8px var(--map-beacon);
}

.course-map-beacon::before {
  content: '';
  position: absolute;
  left: 50%;
  bottom: 15px;
  width: 1px;
  height: 10px;
  background: linear-gradient(to top, var(--map-beacon), transparent);
  transform: translateX(-50%);
}

.course-map-beacon::after {
  content: '';
  position: absolute;
  inset: -7px;
  border: 1px solid color-mix(in srgb, var(--map-beacon) 38%, transparent);
  border-radius: 50%;
  animation: course-map-beacon-pulse 4s ease-out infinite;
}

@keyframes course-map-beacon-pulse {
  0% {
    opacity: 0.5;
    transform: scale(0.78);
  }

  72%,
  100% {
    opacity: 0;
    transform: scale(1.4);
  }
}

[data-course-map-editor] .course-map-node {
  cursor: grab;
}

.course-map-status {
  position: absolute;
  top: 14px;
  left: 50%;
  z-index: 8;
  max-width: min(520px, calc(100% - 30px));
  margin: 0;
  padding: 9px 13px;
  border: 1px solid var(--course-line);
  border-radius: 999px;
  background: var(--course-surface-solid);
  color: var(--bbs-shell-muted);
  font-size: 0.8rem;
  transform: translateX(-50%);
}

.course-map-status.is-error,
.course-editor-message.is-error,
#course-edge-status.is-error,
.markdown-save-status.is-error {
  color: #a03d3d !important;
}

/* Map editor */
.course-editor-shell {
  width: min(100%, 1500px);
  display: grid;
  gap: 14px;
  margin: 0 auto;
}

.course-editor-header {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 20px;
  padding: 22px 24px;
  border: 1px solid var(--course-line);
  border-radius: 8px;
  background: var(--course-surface);
}

.course-editor-header h1,
.markdown-editor-header h1 {
  margin: 0;
  color: var(--bbs-shell-text);
  font-size: clamp(1.8rem, 4vw, 3.2rem);
  line-height: 1.08;
}

.course-editor-header p:not(.course-kicker),
.markdown-editor-header p:not(.course-kicker) {
  margin: 8px 0 0;
  color: var(--bbs-shell-muted);
}

.course-editor-layout {
  display: grid;
  grid-template-columns: 310px minmax(0, 1fr);
  gap: 14px;
}

.course-editor-sidebar {
  display: grid;
  align-content: start;
  gap: 12px;
}

.course-editor-tools,
.course-node-form,
.course-edge-list-panel {
  display: grid;
  gap: 12px;
  padding: 16px;
  border: 1px solid var(--course-line);
  border-radius: 8px;
  background: var(--course-surface);
}

.course-editor-sidebar h2 {
  margin: 0;
  color: var(--bbs-shell-text);
  font-size: 0.95rem;
}

.course-edge-tools,
.course-node-form-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.course-edge-tools button,
.course-node-form-actions button,
.course-node-form-actions a,
.course-edge-list-item button {
  min-height: 38px;
  padding: 0 11px;
  border: 1px solid var(--course-line-strong);
  border-radius: 7px;
  background: var(--course-surface-solid);
  color: var(--bbs-shell-text) !important;
  font-size: 0.78rem;
  font-weight: 900;
  cursor: pointer;
}

.course-edge-tools button.is-active,
.course-node-form-actions .is-primary {
  border-color: var(--course-primary);
  background: var(--course-primary);
  color: #ffffff !important;
}

.course-node-form-actions .is-danger {
  color: #973c3c !important;
}

#course-edge-status,
.course-editor-message {
  min-height: 1.4em;
  margin: 0;
  color: var(--bbs-shell-muted);
  font-size: 0.76rem;
  line-height: 1.5;
}

.course-node-form label {
  display: grid;
  gap: 6px;
  color: var(--bbs-shell-muted);
  font-size: 0.76rem;
  font-weight: 900;
}

.course-node-form input,
.course-node-form textarea {
  width: 100%;
  padding: 10px 11px;
  border: 1px solid var(--course-line-strong);
  border-radius: 7px;
  background: var(--course-surface-solid);
  color: var(--bbs-shell-text);
  outline: none;
  resize: vertical;
}

.course-position-fields {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 8px;
}

.course-edge-list-panel {
  max-height: 330px;
  overflow: auto;
}

.course-edge-list-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
  padding: 8px 0;
  border-bottom: 1px solid var(--course-line);
  color: var(--bbs-shell-muted);
  font-family: var(--font-ui);
  font-size: 0.72rem;
}

.course-editor-layout.is-readonly .course-editor-sidebar,
.course-editor-layout.is-readonly .course-map-scroller {
  pointer-events: none;
  opacity: 0.55;
}

/* Immersive knowledge map studio */
body.course-map-editor-page {
  overflow: hidden;
  background: #061216;
}

body.course-map-editor-page > .page-shell {
  min-height: 100dvh;
  padding: 0 !important;
  background: #061216 !important;
}

body.course-map-editor-page .topbar,
body.course-map-editor-page .mobile-nav,
body.course-map-editor-page .site-footer {
  display: none !important;
}

.course-map-editor-immersive {
  position: fixed;
  inset: 0;
  z-index: 200;
  width: 100vw;
  height: 100dvh;
  overflow: hidden;
  color: #eafffb;
  background: #061216;
}

.course-map-editor-immersive .course-map-panel {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  min-height: 0;
  border: 0;
  border-radius: 0;
}

.course-map-editor-immersive .course-map-scroller {
  width: 100%;
  height: 100dvh;
  min-height: 0;
  overflow: auto;
  cursor: grab;
  scrollbar-color: rgba(118, 220, 211, 0.32) transparent;
  scrollbar-width: thin;
}

.course-map-editor-immersive .course-map-scroller.is-panning {
  cursor: grabbing;
  user-select: none;
}

.course-map-editor-immersive .course-map-scroller.is-connecting {
  cursor: crosshair;
}

.course-map-editor-immersive .course-map-node {
  margin-top: 104px;
  margin-left: 96px;
}

.course-map-editor-immersive .course-map-edges {
  transform: translate(96px, 104px);
}

.course-map-studio-bar {
  position: fixed;
  top: max(14px, env(safe-area-inset-top));
  left: 50%;
  z-index: 220;
  width: min(calc(100vw - 32px), 840px);
  min-height: 58px;
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto minmax(0, 1fr);
  align-items: center;
  gap: 16px;
  padding: 7px 8px 7px 10px;
  border: 1px solid rgba(137, 239, 230, 0.2);
  border-radius: 14px;
  background: rgba(5, 24, 29, 0.82);
  box-shadow:
    inset 0 1px 0 rgba(222, 255, 251, 0.06),
    0 18px 45px rgba(0, 7, 10, 0.3);
  transform: translateX(-50%);
  backdrop-filter: blur(20px) saturate(1.15);
  -webkit-backdrop-filter: blur(20px) saturate(1.15);
}

.course-map-studio-identity {
  min-width: 0;
  display: flex;
  align-items: center;
  gap: 10px;
}

.course-map-studio-back,
.course-map-studio-preview,
.course-map-studio-tools button,
.course-map-panel-close {
  display: grid;
  place-items: center;
  border: 1px solid rgba(137, 239, 230, 0.16);
  background: rgba(137, 239, 230, 0.06);
  color: rgba(232, 255, 251, 0.86) !important;
  cursor: pointer;
  transition:
    color 180ms ease,
    border-color 180ms ease,
    background 180ms ease,
    transform 180ms ease;
}

.course-map-studio-back {
  width: 42px;
  height: 42px;
  flex: 0 0 auto;
  border-radius: 10px;
}

.course-map-studio-back svg,
.course-map-studio-preview svg,
.course-map-studio-tools svg {
  width: 20px;
  height: 20px;
  fill: none;
  stroke: currentColor;
  stroke-linecap: round;
  stroke-linejoin: round;
  stroke-width: 1.7;
}

.course-map-studio-identity > div {
  min-width: 0;
}

.course-map-studio-identity span,
.course-map-panel-heading span {
  display: block;
  margin-bottom: 2px;
  color: rgba(137, 239, 230, 0.56);
  font-family: 'SFMono-Regular', Consolas, monospace;
  font-size: 0.58rem;
  font-weight: 700;
  letter-spacing: 0.17em;
}

.course-map-studio-identity h1 {
  margin: 0;
  overflow: hidden;
  color: #eafffb;
  font-family: 'PingFang SC', 'Microsoft YaHei', sans-serif;
  font-size: 0.88rem;
  font-weight: 600;
  line-height: 1.25;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.course-map-studio-save-state {
  margin: 0;
  color: rgba(224, 250, 247, 0.5);
  font-family: 'SFMono-Regular', Consolas, monospace;
  font-size: 0.68rem;
  font-variant-numeric: tabular-nums;
  white-space: nowrap;
}

.course-map-studio-save-state.is-error {
  color: #ffaaa2;
}

.course-map-studio-preview {
  min-height: 42px;
  display: inline-flex;
  justify-self: end;
  grid-column: 3;
  gap: 7px;
  padding: 0 13px;
  border-radius: 10px;
  font-size: 0.76rem;
  font-weight: 700;
}

.course-map-studio-back:hover,
.course-map-studio-preview:hover,
.course-map-studio-tools button:hover,
.course-map-studio-tools button:focus-visible,
.course-map-panel-close:hover {
  border-color: rgba(137, 239, 230, 0.48);
  background: rgba(137, 239, 230, 0.13);
  color: #ffffff !important;
}

.course-map-studio-back:active,
.course-map-studio-preview:active,
.course-map-studio-tools button:active {
  transform: scale(0.96);
}

.course-map-studio-tools {
  position: fixed;
  top: 50%;
  left: max(18px, env(safe-area-inset-left));
  z-index: 220;
  display: grid;
  gap: 5px;
  padding: 7px;
  border: 1px solid rgba(137, 239, 230, 0.2);
  border-radius: 13px;
  background: rgba(5, 24, 29, 0.84);
  box-shadow:
    inset 0 1px 0 rgba(222, 255, 251, 0.06),
    0 18px 45px rgba(0, 7, 10, 0.3);
  transform: translateY(-50%);
  backdrop-filter: blur(18px);
  -webkit-backdrop-filter: blur(18px);
}

.course-map-studio-tools button {
  position: relative;
  width: 42px;
  height: 42px;
  border-radius: 9px;
}

.course-map-studio-tools button.is-active {
  border-color: rgba(146, 250, 241, 0.72);
  background: rgba(90, 218, 207, 0.2);
  color: #c8fff9 !important;
  box-shadow: inset 0 0 16px rgba(80, 226, 213, 0.1);
}

.course-map-studio-tools button::after {
  content: attr(data-tooltip);
  position: absolute;
  top: 50%;
  left: calc(100% + 12px);
  width: max-content;
  max-width: 160px;
  padding: 6px 9px;
  border: 1px solid rgba(137, 239, 230, 0.18);
  border-radius: 6px;
  background: rgba(3, 17, 21, 0.94);
  color: rgba(235, 255, 252, 0.86);
  font-size: 0.68rem;
  font-weight: 600;
  opacity: 0;
  pointer-events: none;
  transform: translate(4px, -50%);
  transition:
    opacity 140ms ease,
    transform 140ms ease;
}

.course-map-studio-tools button:hover::after,
.course-map-studio-tools button:focus-visible::after {
  opacity: 1;
  transform: translate(0, -50%);
}

.course-map-tool-divider {
  width: 24px;
  height: 1px;
  margin: 3px auto;
  background: rgba(137, 239, 230, 0.16);
}

.course-map-studio-panel {
  position: fixed;
  top: max(88px, calc(env(safe-area-inset-top) + 78px));
  right: max(18px, env(safe-area-inset-right));
  bottom: max(22px, env(safe-area-inset-bottom));
  z-index: 225;
  width: min(340px, calc(100vw - 36px));
  display: flex;
  flex-direction: column;
  gap: 18px;
  padding: 18px;
  overflow: auto;
  border: 1px solid rgba(137, 239, 230, 0.2);
  border-radius: 14px;
  background: rgba(5, 24, 29, 0.9);
  color: #eafffb;
  box-shadow:
    inset 0 1px 0 rgba(222, 255, 251, 0.06),
    -18px 24px 58px rgba(0, 7, 10, 0.32);
  backdrop-filter: blur(22px) saturate(1.12);
  -webkit-backdrop-filter: blur(22px) saturate(1.12);
}

.course-map-studio-panel.hidden {
  display: none;
}

.course-map-panel-heading {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  padding-bottom: 14px;
  border-bottom: 1px solid rgba(137, 239, 230, 0.13);
}

.course-map-panel-heading h2 {
  margin: 0;
  color: #f1fffd;
  font-size: 1.02rem;
  font-weight: 600;
}

.course-map-panel-close {
  width: 34px;
  height: 34px;
  flex: 0 0 auto;
  border-radius: 8px;
  font-size: 1.25rem;
  line-height: 1;
}

.course-map-studio-panel .course-node-form {
  display: grid;
  gap: 13px;
  padding: 0;
  border: 0;
  background: transparent;
}

.course-map-studio-panel .course-node-form.hidden {
  display: none;
}

.course-map-studio-panel .course-node-form label {
  color: rgba(224, 250, 247, 0.56);
  font-size: 0.69rem;
  font-weight: 600;
  letter-spacing: 0.03em;
}

.course-map-studio-panel .course-node-form input,
.course-map-studio-panel .course-node-form textarea {
  border-color: rgba(137, 239, 230, 0.18);
  border-radius: 8px;
  background: rgba(137, 239, 230, 0.055);
  color: #effffc;
}

.course-map-studio-panel .course-node-form input:focus,
.course-map-studio-panel .course-node-form textarea:focus {
  border-color: rgba(137, 239, 230, 0.62);
  box-shadow: 0 0 0 3px rgba(86, 218, 207, 0.09);
}

.course-map-studio-panel .course-node-form input[readonly] {
  color: rgba(189, 236, 230, 0.58);
}

.course-map-studio-panel .course-node-form-actions button,
.course-map-studio-panel .course-node-form-actions a,
.course-map-background-actions button {
  min-height: 40px;
  border-color: rgba(137, 239, 230, 0.2);
  border-radius: 8px;
  background: rgba(137, 239, 230, 0.06);
  color: rgba(237, 255, 252, 0.84) !important;
}

.course-map-studio-panel .course-node-form-actions .is-primary,
.course-map-background-actions .is-primary {
  border-color: #6ad5cc;
  background: #5dc6bd;
  color: #032327 !important;
}

.course-map-studio-panel .course-node-form-actions .is-danger {
  margin-left: auto;
  color: #ffaaa2 !important;
}

.course-map-studio-panel .course-edge-list-panel {
  max-height: none;
  padding: 0;
  overflow: visible;
  border: 0;
  background: transparent;
}

.course-map-studio-panel .course-edge-list-item {
  padding: 11px 0;
  border-color: rgba(137, 239, 230, 0.12);
  color: rgba(221, 249, 245, 0.66);
}

.course-map-studio-panel .course-edge-list-item button {
  min-height: 32px;
  border-color: rgba(255, 170, 162, 0.2);
  background: rgba(255, 170, 162, 0.06);
  color: #ffaaa2 !important;
}

.course-map-background-settings {
  display: grid;
  gap: 14px;
}

.course-map-background-preview {
  position: relative;
  aspect-ratio: 16 / 9;
  display: grid;
  place-items: center;
  overflow: hidden;
  border: 1px solid rgba(137, 239, 230, 0.18);
  border-radius: 10px;
  background:
    radial-gradient(circle at 30% 28%, rgba(62, 177, 176, 0.24), transparent 30%),
    linear-gradient(rgba(129, 226, 218, 0.07) 1px, transparent 1px),
    linear-gradient(90deg, rgba(129, 226, 218, 0.07) 1px, transparent 1px), #071a1f;
  background-position: center;
  background-size:
    auto,
    24px 24px,
    24px 24px,
    auto;
}

.course-map-background-preview.has-image {
  background-position: center;
  background-size: cover;
}

.course-map-background-preview::after {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(rgba(3, 16, 20, 0.2), rgba(3, 16, 20, 0.55));
}

.course-map-background-preview span {
  position: relative;
  z-index: 1;
  color: rgba(231, 255, 251, 0.74);
  font-size: 0.72rem;
}

.course-map-background-settings > p {
  margin: 0;
  color: rgba(221, 249, 245, 0.55);
  font-size: 0.76rem;
  line-height: 1.65;
}

.course-map-background-actions {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 8px;
}

.course-map-background-actions button {
  cursor: pointer;
}

.course-map-background-actions button:disabled {
  cursor: not-allowed;
  opacity: 0.4;
}

.course-map-studio-hint {
  position: fixed;
  bottom: max(18px, env(safe-area-inset-bottom));
  left: 50%;
  z-index: 218;
  max-width: min(620px, calc(100vw - 150px));
  margin: 0;
  padding: 8px 12px;
  border: 1px solid rgba(137, 239, 230, 0.12);
  border-radius: 8px;
  background: rgba(3, 17, 21, 0.72);
  color: rgba(224, 250, 247, 0.5);
  font-family: 'SFMono-Regular', Consolas, monospace;
  font-size: 0.65rem;
  pointer-events: none;
  transform: translateX(-50%);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
}

.course-map-studio-hint.is-error {
  border-color: rgba(255, 170, 162, 0.24);
  color: #ffaaa2;
}

.course-map-editor-immersive .course-map-status {
  top: max(88px, calc(env(safe-area-inset-top) + 78px));
  border-color: rgba(137, 239, 230, 0.18);
  border-radius: 8px;
  background: rgba(3, 17, 21, 0.86);
  color: rgba(231, 255, 251, 0.72);
  box-shadow: 0 12px 32px rgba(0, 7, 10, 0.24);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
}

.course-map-immersive .course-map-status {
  top: max(104px, calc(env(safe-area-inset-top) + 94px));
  border-color: var(--course-line-strong);
  border-radius: 999px;
  background: color-mix(in srgb, var(--course-surface-solid) 92%, transparent);
  color: var(--bbs-shell-muted);
  box-shadow: 0 12px 32px rgba(7, 9, 11, 0.12);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
}

.course-map-editor-immersive.is-readonly .course-map-studio-tools {
  opacity: 0.46;
}

@media (max-width: 1120px) {
  .course-map-directory-layout {
    grid-template-columns: 230px minmax(0, 1fr);
    padding-right: 24px;
    padding-left: 24px;
  }

  .course-map-directory-nodes {
    grid-template-columns: repeat(2, minmax(170px, 1fr));
  }

  .course-map-chapter-grid {
    grid-template-columns: repeat(2, minmax(260px, 1fr));
    padding-right: clamp(24px, 5vw, 60px);
    padding-left: clamp(24px, 5vw, 60px);
  }

  .course-map-focus-workspace {
    padding-right: clamp(24px, 5vw, 60px);
    padding-left: clamp(24px, 5vw, 60px);
  }

  .course-map-focus-stage {
    grid-template-columns: minmax(170px, 1fr) minmax(220px, 260px) minmax(170px, 1fr);
    gap: clamp(18px, 3vw, 38px);
    padding-right: clamp(20px, 3vw, 38px);
    padding-left: clamp(20px, 3vw, 38px);
  }

  .course-map-chapter-grid.is-focus-rest {
    grid-template-columns: repeat(3, minmax(220px, 1fr));
  }
}

@media (max-width: 900px) {
  .course-map-directory-layout {
    grid-template-columns: 205px minmax(0, 1fr);
    gap: 15px;
    padding-right: 16px;
    padding-left: 16px;
  }

  .course-map-index-heading {
    padding-right: 13px;
    padding-left: 13px;
  }

  .course-map-directory-current {
    grid-template-columns: minmax(0, 1fr);
    gap: 18px;
  }

  .course-map-directory-current-actions {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .course-map-focus-workspace {
    gap: 24px;
  }

  .course-map-focus-stage {
    grid-template-columns: minmax(150px, 1fr) minmax(200px, 230px) minmax(150px, 1fr);
    gap: 16px;
  }

  .course-map-chapter-grid.is-focus-rest {
    grid-template-columns: repeat(2, minmax(220px, 1fr));
  }
}

@media (max-width: 720px) {
  .course-map-reader-hud {
    top: max(12px, env(safe-area-inset-top));
    right: max(12px, env(safe-area-inset-right));
    left: auto;
    width: min(210px, calc(100vw - 132px));
    max-width: none;
    padding: 11px 13px;
  }

  .course-map-reader-controls {
    top: max(12px, env(safe-area-inset-top));
    left: max(12px, env(safe-area-inset-left));
    gap: 6px;
  }

  .course-map-reader-control {
    width: 42px;
    height: 42px;
  }

  .course-map-reader-hud > p,
  .course-map-reader-hud > small,
  .course-map-reader-legend {
    display: none;
  }

  .course-map-reader-hud > strong {
    max-width: 180px;
    display: block;
    font-size: 0.86rem;
  }

  .course-map-directory-layout {
    grid-template-columns: minmax(0, 1fr);
    gap: 14px;
    padding: 102px 12px 70px;
  }

  .course-map-index-heading {
    padding: 13px 14px 11px;
  }

  .course-map-index-list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 4px;
  }

  .course-map-index-item {
    min-height: 52px;
    grid-template-columns: 28px minmax(0, 1fr);
    gap: 7px;
    padding: 6px 8px;
  }

  .course-map-index-item > i,
  .course-map-index-copy span {
    display: none;
  }

  .course-map-index-number {
    width: 27px;
    height: 27px;
  }

  .course-map-directory-heading {
    min-height: 72px;
    align-items: start;
    padding: 14px 16px;
  }

  .course-map-directory-heading p {
    display: none;
  }

  .course-map-directory-current {
    margin: 12px 12px 0;
    padding: 20px 17px;
  }

  .course-map-directory-current-copy h2 {
    font-size: 1.55rem;
  }

  .course-map-directory-section-heading {
    padding: 20px 14px 10px;
  }

  .course-map-directory-nodes {
    grid-template-columns: minmax(0, 1fr);
    padding: 0 12px 14px;
  }

  .course-map-chapter-grid {
    grid-template-columns: minmax(0, 1fr);
    gap: 18px;
    padding: 108px 14px 76px;
  }

  .course-map-focus-workspace {
    gap: 18px;
    padding: 108px 14px 24px;
  }

  .course-map-focused-heading {
    grid-template-columns: 44px minmax(0, 1fr);
    padding: 16px;
  }

  .course-map-focused-heading > button {
    grid-column: 1 / -1;
    justify-self: stretch;
  }

  .course-map-focus-stage {
    grid-template-columns: minmax(0, 1fr);
    gap: 14px;
    min-height: 0;
    padding: 18px 14px;
  }

  .course-map-focus-center {
    grid-row: 1;
  }

  .course-map-focus-side.is-left,
  .course-map-focus-side.is-right {
    justify-items: stretch;
  }

  .course-map-focus-side.is-left .course-map-focus-direction,
  .course-map-focus-side.is-right .course-map-focus-direction {
    text-align: left;
  }

  .course-map-focus-side .course-map-topic {
    width: 100%;
  }

  .course-map-focus-summary {
    display: grid;
    padding: 12px 16px 16px;
  }

  .course-map-cross-grid {
    grid-template-columns: minmax(0, 1fr);
  }

  .course-map-chapter-grid.is-focus-rest {
    grid-template-columns: minmax(0, 1fr);
    padding: 24px 14px 76px;
  }

  .course-map-chapter-card.is-collapsed,
  .course-map-chapter-card.is-collapsed:hover,
  .course-map-chapter-card.is-collapsed:focus-within {
    transform: none;
  }

  .course-map-chapter-card.is-expanded {
    grid-column: span 1;
  }

  .course-map-chapter-toggle {
    grid-template-columns: 48px minmax(0, 1fr) auto;
    gap: 11px;
    min-height: 126px;
    padding: 19px 16px;
  }

  .course-map-chapter-orbit {
    width: 44px;
    height: 44px;
  }

  .course-map-chapter-nodes {
    grid-template-columns: repeat(auto-fit, minmax(155px, 1fr));
    gap: 9px;
    padding: 0 12px 14px;
  }

  .course-map-topic-main strong {
    font-size: 0.79rem;
  }

  .course-map-studio-bar {
    top: max(10px, env(safe-area-inset-top));
    width: calc(100vw - 20px);
    grid-template-columns: minmax(0, 1fr) auto;
    gap: 8px;
  }

  .course-map-studio-save-state {
    display: none;
  }

  .course-map-studio-preview {
    grid-column: 2;
    padding: 0 10px;
  }

  .course-map-studio-preview span {
    display: none;
  }

  .course-map-studio-tools {
    top: auto;
    bottom: max(12px, env(safe-area-inset-bottom));
    left: 50%;
    display: flex;
    gap: 4px;
    max-width: calc(100vw - 20px);
    overflow-x: auto;
    transform: translateX(-50%);
  }

  .course-map-studio-tools button::after {
    display: none;
  }

  .course-map-tool-divider {
    width: 1px;
    height: 24px;
    margin: auto 3px;
  }

  .course-map-studio-panel {
    top: auto;
    right: 10px;
    bottom: calc(max(72px, env(safe-area-inset-bottom) + 62px));
    left: 10px;
    width: auto;
    max-height: min(68dvh, 620px);
    border-radius: 14px 14px 10px 10px;
  }

  .course-map-studio-hint {
    display: none;
  }

  .course-map-editor-immersive .course-map-status {
    top: max(80px, calc(env(safe-area-inset-top) + 72px));
  }
}

@media (prefers-reduced-motion: reduce) {
  .course-map-beacon::after {
    animation: none;
    opacity: 0.45;
  }

  .course-map-edge-pulse {
    display: none;
    animation: none;
  }

  .course-map-topic.is-learning::before {
    animation: none;
  }

  .course-map-background,
  .course-map-node,
  .course-map-hologram {
    transition: none;
  }
}

/* Knowledge workspace: VS Code-style primary and secondary sidebars. */
.course-material-immersive {
  padding: 72px 24px 36px;
}

.knowledge-workbench {
  --knowledge-tools-width: 214px;
  --knowledge-interaction-width: 33vw;
  width: min(100%, 1840px);
  display: grid;
  grid-template-columns: var(--knowledge-tools-width) minmax(0, 1fr);
  align-items: start;
  gap: 18px;
  margin: 0 auto;
  transition: grid-template-columns 180ms ease;
}

.knowledge-workbench.is-tools-collapsed {
  --knowledge-tools-width: 68px;
}

.knowledge-workbench.is-interaction-open {
  grid-template-columns:
    var(--knowledge-tools-width) minmax(0, 1fr) 8px
    var(--knowledge-interaction-width);
  gap: 12px;
}

.knowledge-tools {
  position: sticky;
  top: 24px;
  height: calc(100dvh - 48px);
  min-width: 0;
  display: grid;
  grid-template-rows: auto minmax(0, 1fr) auto;
  overflow: hidden;
  border: 1px solid var(--course-line-strong);
  border-radius: 16px;
  background: color-mix(in srgb, var(--course-surface-solid) 94%, transparent);
  box-shadow: 0 18px 48px rgba(1, 8, 11, 0.16);
  backdrop-filter: blur(18px);
  -webkit-backdrop-filter: blur(18px);
}

.knowledge-tools-header {
  min-height: 68px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  padding: 12px 12px 12px 16px;
  border-bottom: 1px solid var(--course-line);
}

.knowledge-tools-header > span {
  min-width: 0;
  display: grid;
  gap: 3px;
}

.knowledge-tools-header small {
  color: var(--course-accent);
  font-family: 'SFMono-Regular', Consolas, monospace;
  font-size: 0.56rem;
  font-weight: 900;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.knowledge-tools-header strong {
  color: var(--bbs-shell-text);
  font-size: 1rem;
}

.knowledge-tools-header button {
  width: 32px;
  height: 32px;
  flex: 0 0 auto;
  display: grid;
  place-items: center;
  padding: 0;
  border: 1px solid var(--course-line);
  border-radius: 8px;
  background: var(--course-neutral-surface);
  color: var(--bbs-shell-muted);
  font-size: 1rem;
  cursor: pointer;
}

.knowledge-tools-header button:hover,
.knowledge-tools-header button:focus-visible {
  border-color: var(--course-accent);
  color: var(--course-accent);
  outline: none;
}

.knowledge-tools-list {
  min-height: 0;
  display: grid;
  align-content: start;
  gap: 7px;
  padding: 12px 10px;
  overflow-y: auto;
}

.knowledge-tools-list button {
  width: 100%;
  min-height: 50px;
  display: grid;
  grid-template-columns: 30px minmax(0, 1fr);
  align-items: center;
  gap: 9px;
  padding: 8px 10px;
  border: 1px solid transparent;
  border-radius: 10px;
  background: transparent;
  color: var(--bbs-shell-muted);
  text-align: left;
  cursor: pointer;
}

.knowledge-tools-list button > span {
  width: 30px;
  height: 30px;
  display: grid;
  place-items: center;
  border-radius: 8px;
  background: var(--course-neutral-surface);
  color: var(--course-accent);
  font-size: 0.88rem;
  font-weight: 900;
}

.knowledge-tools-list button > strong {
  overflow: hidden;
  font-size: 0.78rem;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.knowledge-tools-list button:hover,
.knowledge-tools-list button:focus-visible {
  border-color: var(--course-line-strong);
  background: var(--course-neutral-surface);
  color: var(--bbs-shell-text);
  outline: none;
}

.knowledge-tools-list button.is-active {
  border-color: color-mix(in srgb, var(--course-accent) 42%, var(--course-line));
  background: var(--course-accent-soft);
  color: var(--bbs-shell-text);
  box-shadow: inset 3px 0 0 var(--course-accent);
}

.knowledge-tools-status {
  min-height: 54px;
  display: flex;
  align-items: center;
  gap: 9px;
  padding: 11px 14px;
  border-top: 1px solid var(--course-line);
  color: var(--bbs-shell-muted);
}

.knowledge-tools-status > span {
  width: 8px;
  height: 8px;
  flex: 0 0 auto;
  border-radius: 50%;
  background: var(--course-accent);
  box-shadow: 0 0 0 4px var(--course-accent-soft);
}

.knowledge-tools-status p {
  margin: 0;
  font-size: 0.62rem;
  font-weight: 750;
}

.knowledge-workbench.is-tools-collapsed .knowledge-tools-header {
  justify-content: center;
  padding-right: 8px;
  padding-left: 8px;
}

.knowledge-workbench.is-tools-collapsed .knowledge-tools-header > span,
.knowledge-workbench.is-tools-collapsed .knowledge-tools-list button > strong,
.knowledge-workbench.is-tools-collapsed .knowledge-tools-status p {
  display: none;
}

.knowledge-workbench.is-tools-collapsed .knowledge-tools-list {
  padding-right: 8px;
  padding-left: 8px;
}

.knowledge-workbench.is-tools-collapsed .knowledge-tools-list button {
  grid-template-columns: minmax(0, 1fr);
  justify-items: center;
  padding-right: 6px;
  padding-left: 6px;
}

.knowledge-workbench.is-tools-collapsed .knowledge-tools-status {
  justify-content: center;
  padding-right: 0;
  padding-left: 0;
}

.knowledge-workbench .course-material-reader {
  grid-column: 2;
  width: 100%;
  max-width: none;
  min-width: 0;
  gap: 24px;
  margin: 0;
}

.knowledge-workbench .course-material-body {
  max-width: none;
}

.knowledge-panel-resizer {
  position: sticky;
  top: 24px;
  height: calc(100dvh - 48px);
  display: none;
  align-items: center;
  justify-content: center;
  border-radius: 999px;
  background: color-mix(in srgb, var(--course-line-strong) 58%, transparent);
  cursor: col-resize;
  touch-action: none;
}

.knowledge-workbench.is-interaction-open .knowledge-panel-resizer:not(.hidden) {
  display: flex;
}

.knowledge-panel-resizer > span {
  width: 28px;
  height: 28px;
  display: grid;
  place-items: center;
  border: 1px solid color-mix(in srgb, var(--course-accent) 54%, var(--course-line));
  border-radius: 50%;
  background: var(--course-primary);
  color: #ffffff;
  font-size: 0.72rem;
  transform: rotate(90deg);
}

.knowledge-panel-resizer:hover,
.knowledge-panel-resizer:focus-visible {
  background: var(--course-accent);
  outline: none;
}

body.is-resizing-knowledge-panel,
body.is-resizing-knowledge-panel * {
  cursor: col-resize !important;
  user-select: none !important;
}

.knowledge-chat {
  grid-column: 4;
  min-width: 0;
  position: sticky;
  top: 24px;
  height: calc(100dvh - 48px);
  display: none;
}

.knowledge-workbench.is-interaction-open .knowledge-chat {
  display: block;
}

.knowledge-chat-panel {
  position: static;
  width: 100%;
  height: 100%;
  min-height: 0;
  max-height: none;
  border-radius: 16px;
  box-shadow: 0 18px 54px rgba(1, 8, 11, 0.2);
  animation: knowledge-chat-side-enter 180ms ease-out;
}

@keyframes knowledge-chat-side-enter {
  from {
    opacity: 0;
    transform: translateX(10px);
  }

  to {
    opacity: 1;
    transform: translateX(0);
  }
}

.knowledge-chat-fab {
  right: max(22px, env(safe-area-inset-right));
  bottom: max(22px, env(safe-area-inset-bottom));
  z-index: 290;
}

.knowledge-chat-fab-symbol {
  width: 34px;
  height: 34px;
  display: grid;
  place-items: center;
  color: #ffffff;
  font-size: 2rem;
  font-weight: 300;
  line-height: 1;
}

.knowledge-chat-fab.is-active {
  transform: none;
}

.knowledge-sequence-navigation {
  min-width: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px;
  padding: 10px;
  border: 1px solid var(--course-line-strong);
  border-radius: 14px;
  background: color-mix(in srgb, var(--course-surface-solid) 92%, transparent);
  box-shadow: 0 14px 38px rgba(1, 8, 11, 0.12);
}

.knowledge-sequence-link {
  min-width: 0;
  min-height: 72px;
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  align-items: center;
  gap: 11px;
  padding: 11px 14px;
  border: 1px solid var(--course-line);
  border-radius: 10px;
  background: var(--course-neutral-surface);
  color: var(--bbs-shell-text) !important;
  text-decoration: none;
  transition:
    border-color 160ms ease,
    background 160ms ease,
    transform 160ms ease;
}

.knowledge-sequence-link.is-next {
  grid-template-columns: minmax(0, 1fr) auto;
  text-align: right;
}

.knowledge-sequence-link > span:not([aria-hidden]) {
  min-width: 0;
  display: grid;
  gap: 5px;
}

.knowledge-sequence-link > span[aria-hidden] {
  color: var(--course-accent);
  font-size: 1.15rem;
  font-weight: 900;
}

.knowledge-sequence-link small {
  color: var(--bbs-shell-muted);
  font-size: 0.62rem;
  font-weight: 850;
}

.knowledge-sequence-link strong {
  overflow: hidden;
  color: var(--bbs-shell-text);
  font-size: 0.76rem;
  line-height: 1.35;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.knowledge-sequence-link:hover,
.knowledge-sequence-link:focus-visible {
  border-color: var(--course-accent);
  background: var(--course-accent-soft);
  outline: none;
  transform: translateY(-2px);
}

.knowledge-sequence-link.is-disabled {
  opacity: 0.46;
  pointer-events: none;
}

@media (max-width: 1180px) {
  .knowledge-workbench {
    --knowledge-tools-width: 180px;
  }

  .knowledge-workbench.is-tools-collapsed {
    --knowledge-tools-width: 64px;
  }

  .knowledge-tools-list button {
    padding-right: 7px;
    padding-left: 7px;
  }
}

@media (max-width: 920px) {
  .course-material-immersive {
    padding-right: 14px;
    padding-left: 14px;
  }

  .knowledge-workbench,
  .knowledge-workbench.is-interaction-open,
  .knowledge-workbench.is-tools-collapsed {
    grid-template-columns: 62px minmax(0, 1fr);
    gap: 12px;
  }

  .knowledge-tools-header {
    justify-content: center;
    padding-right: 8px;
    padding-left: 8px;
  }

  .knowledge-tools-header > span,
  .knowledge-tools-header button,
  .knowledge-tools-list button > strong,
  .knowledge-tools-status p {
    display: none;
  }

  .knowledge-tools-list {
    padding-right: 7px;
    padding-left: 7px;
  }

  .knowledge-tools-list button {
    grid-template-columns: minmax(0, 1fr);
    justify-items: center;
    padding-right: 4px;
    padding-left: 4px;
  }

  .knowledge-tools-status {
    justify-content: center;
    padding-right: 0;
    padding-left: 0;
  }

  .knowledge-panel-resizer,
  .knowledge-workbench.is-interaction-open .knowledge-panel-resizer:not(.hidden) {
    display: none;
  }

  .knowledge-chat,
  .knowledge-workbench.is-interaction-open .knowledge-chat {
    position: fixed;
    top: 0;
    right: 0;
    bottom: 0;
    z-index: 280;
    width: min(92vw, 520px);
    height: 100dvh;
  }

  .knowledge-chat-panel {
    height: 100dvh;
    border-radius: 16px 0 0 16px;
  }
}

@media (max-width: 620px) {
  .course-material-immersive {
    padding: 72px 10px 92px;
  }

  .knowledge-workbench,
  .knowledge-workbench.is-interaction-open,
  .knowledge-workbench.is-tools-collapsed {
    grid-template-columns: 54px minmax(0, 1fr);
    gap: 8px;
  }

  .knowledge-tools {
    top: 12px;
    height: calc(100dvh - 24px);
    border-radius: 12px;
  }

  .knowledge-tools-list button > span {
    width: 28px;
    height: 28px;
  }

  .knowledge-sequence-navigation {
    grid-template-columns: minmax(0, 1fr);
  }

  .knowledge-sequence-link.is-next {
    text-align: left;
  }

  .knowledge-chat,
  .knowledge-workbench.is-interaction-open .knowledge-chat {
    width: 100vw;
  }

  .knowledge-chat-panel {
    border-radius: 0;
  }
}

/* Markdown editor */
.markdown-editor-shell {
  width: min(100%, 1500px);
  display: grid;
  gap: 12px;
  margin: 0 auto;
}

.markdown-editor-header {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 20px;
  padding: 22px 24px;
  border: 1px solid var(--course-line);
  border-radius: 8px;
  background: var(--course-surface);
}

.markdown-toolbar {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 7px;
  padding: 10px 12px;
  border: 1px solid var(--course-line);
  border-radius: 8px;
  background: var(--course-surface);
}

.markdown-toolbar button {
  min-height: 36px;
  padding: 0 11px;
  border: 1px solid var(--course-line-strong);
  border-radius: 7px;
  background: var(--course-surface-solid);
  color: var(--bbs-shell-text);
  font-size: 0.78rem;
  font-weight: 900;
  cursor: pointer;
}

.markdown-save-status {
  margin-left: auto;
  color: var(--bbs-shell-muted);
  font-size: 0.78rem;
}

.markdown-workspace {
  min-height: 70vh;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  overflow: hidden;
  border: 1px solid var(--course-line);
  border-radius: 8px;
  background: var(--course-surface);
}

.markdown-source-panel,
.markdown-preview-panel {
  min-width: 0;
  display: grid;
  grid-template-rows: auto minmax(0, 1fr);
}

.markdown-source-panel {
  border-right: 1px solid var(--course-line);
}

.markdown-source-panel > span,
.markdown-preview-panel > span {
  padding: 9px 13px;
  border-bottom: 1px solid var(--course-line);
  color: var(--bbs-shell-muted);
  font-size: 0.72rem;
  font-weight: 900;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

#markdown-source {
  width: 100%;
  min-height: 68vh;
  padding: 22px;
  border: 0;
  background: var(--course-surface-solid);
  color: var(--bbs-shell-text);
  font-family: 'SFMono-Regular', Consolas, monospace;
  font-size: 0.92rem;
  line-height: 1.7;
  outline: none;
  resize: none;
  tab-size: 2;
}

#markdown-preview {
  min-height: 68vh;
  max-height: 75vh;
  padding: 22px;
  overflow: auto;
  color: var(--bbs-shell-text);
}

@media (max-width: 1000px) {
  .course-editor-layout {
    grid-template-columns: minmax(0, 1fr);
  }

  .course-editor-sidebar {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .course-node-form {
    grid-row: span 2;
  }

  .markdown-workspace {
    grid-template-columns: minmax(0, 1fr);
  }

  .markdown-source-panel {
    border-right: 0;
    border-bottom: 1px solid var(--course-line);
  }

  #markdown-source,
  #markdown-preview {
    min-height: 52vh;
    max-height: none;
  }
}

@media (max-width: 680px) {
  .course-hero,
  .course-editor-header,
  .markdown-editor-header {
    grid-template-columns: minmax(0, 1fr);
    align-items: start;
    flex-direction: column;
  }

  .course-map-actions,
  .course-map-stats {
    justify-content: flex-start;
  }

  .course-map-toolbar .course-map-hint {
    width: 100%;
    margin-left: 0;
  }

  .course-map-scroller {
    min-height: 560px;
  }

  .course-editor-sidebar {
    grid-template-columns: minmax(0, 1fr);
  }

  .markdown-save-status {
    width: 100%;
    margin-left: 0;
  }
}

body.theme-dark.course-page .page-shell-settings,
body.theme-dark.knowledge-page .page-shell-settings {
  background: var(--bbs-shell-page) !important;
}

body.course-page .course-main .course-kicker,
body.knowledge-page .knowledge-main .course-kicker,
body.course-page .course-main .course-modal-meta dt,
body.course-page .course-main .course-resource-type,
body.knowledge-page .knowledge-main .course-resource-type,
body.knowledge-page .knowledge-main .knowledge-back,
body.knowledge-page .knowledge-main .knowledge-rag-message strong {
  color: var(--course-accent) !important;
}

body.course-page .course-main .course-progress span {
  color: var(--bbs-shell-muted) !important;
}

body.course-page .course-main .course-tags span {
  color: var(--course-tag-text) !important;
}

body.course-page .course-main .course-status-badge {
  color: var(--course-neutral-text) !important;
}

body.course-page .course-main .course-status-badge.is-learned {
  color: var(--course-accent) !important;
}

body.course-page .course-main .course-status-badge.is-review {
  color: var(--course-warning-text) !important;
}

body.course-page .course-main .course-discussion-link,
body.course-page .course-main .course-point-actions a,
body.course-page .course-main .course-modal-actions a,
body.knowledge-page .knowledge-main .knowledge-actions a,
body.knowledge-page .knowledge-main .knowledge-actions button.is-active,
body.knowledge-page .knowledge-main .knowledge-section-head a,
body.knowledge-page .knowledge-main .knowledge-rag-form button {
  color: #ffffff !important;
}

.course-shell,
.knowledge-shell {
  width: min(100%, 1220px);
  margin: 0 auto;
}

.course-shell {
  display: grid;
  gap: 18px;
}

.course-hero,
.course-overview,
.course-toolbar,
.course-point-card,
.knowledge-sidebar,
.knowledge-content,
.knowledge-section {
  border: 1px solid var(--course-line);
  border-radius: 8px;
  background: var(--course-surface);
  box-shadow: none;
}

.course-hero {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(260px, 0.34fr);
  gap: 22px;
  align-items: end;
  padding: 28px;
}

.course-kicker {
  margin: 0 0 10px;
  color: var(--course-accent) !important;
  font-family: var(--font-ui);
  font-size: 0.78rem;
  font-weight: 900;
  letter-spacing: 0.12em !important;
  text-transform: uppercase;
}

.course-hero h1,
.knowledge-header h1 {
  margin: 0;
  color: var(--bbs-shell-text) !important;
  font-family: 'Hiragino Sans GB', 'PingFang SC', 'Microsoft YaHei', 'Noto Serif SC', sans-serif;
  font-size: clamp(2.5rem, 6vw, 5.4rem);
  font-weight: 900;
  line-height: 1.02;
}

.course-hero p,
.knowledge-header p,
.course-overview p {
  max-width: 760px;
  margin: 12px 0 0;
  color: var(--bbs-shell-muted) !important;
  font-size: 1rem;
  line-height: 1.85;
}

.course-progress {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 10px;
}

.course-progress span {
  min-height: 84px;
  display: grid;
  align-content: center;
  gap: 6px;
  padding: 14px;
  border: 1px solid var(--course-line);
  border-radius: 8px;
  background: var(--course-surface-soft);
  color: var(--bbs-shell-muted) !important;
  font-size: 0.86rem;
}

.course-progress strong {
  color: var(--bbs-shell-text) !important;
  font-family: var(--font-ui);
  font-size: 1.9rem;
  line-height: 1;
}

.course-overview {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  padding: 20px 22px;
}

.course-overview p {
  margin: 0;
}

.course-discussion-link,
.knowledge-actions a,
.knowledge-section-head a,
.course-point-actions a,
.course-point-actions button,
.course-modal-actions a,
.course-modal-actions button,
.knowledge-actions button,
.knowledge-rag-form button {
  min-height: 44px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 0 16px;
  border: 1px solid var(--course-line-strong);
  border-radius: 8px;
  background: var(--course-primary);
  color: #ffffff !important;
  font-family: var(--font-ui);
  font-size: 0.9rem;
  font-weight: 900;
  cursor: pointer;
}

.course-discussion-link img,
.knowledge-rag-form button img {
  width: 17px;
  height: 17px;
  filter: brightness(0) invert(1);
}

.course-toolbar {
  padding: 18px 22px;
}

.course-search {
  display: grid;
  gap: 8px;
  max-width: 520px;
}

.course-search span {
  color: var(--bbs-shell-muted) !important;
  font-family: var(--font-ui);
  font-size: 0.82rem;
  font-weight: 900;
}

.course-search input,
.knowledge-rag-form textarea {
  width: 100%;
  border: 1px solid var(--course-line-strong);
  border-radius: 8px;
  background: var(--course-surface-solid);
  color: var(--bbs-shell-text) !important;
  outline: none;
}

.course-search input {
  min-height: 44px;
  padding: 0 14px;
}

.course-point-list {
  display: grid;
  gap: 12px;
}

.course-point-card {
  display: grid;
  grid-template-columns: 72px minmax(0, 1fr) auto;
  gap: 18px;
  align-items: stretch;
  padding: 18px;
}

.course-point-index {
  display: grid;
  place-items: center;
  min-height: 100%;
  border-radius: 8px;
  background: var(--course-accent-soft);
  color: var(--course-accent);
  font-family: var(--font-ui);
  font-size: 1.25rem;
  font-weight: 900;
}

.course-point-main {
  min-width: 0;
  display: grid;
  gap: 9px;
}

.course-point-head {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 10px;
}

.course-point-head h2 {
  margin: 0;
  color: var(--bbs-shell-text) !important;
  font-size: 1.25rem;
  line-height: 1.3;
}

.course-point-main p,
.course-point-main small,
.course-muted {
  margin: 0;
  color: var(--bbs-shell-muted) !important;
}

.course-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 7px;
}

.course-tags span,
.course-status-badge {
  display: inline-flex;
  align-items: center;
  min-height: 26px;
  padding: 0 9px;
  border-radius: 999px;
  font-family: var(--font-ui);
  font-size: 0.76rem;
  font-weight: 900;
  line-height: 1;
}

.course-tags span {
  border: 1px solid var(--course-line);
  background: var(--course-tag-surface);
  color: var(--course-tag-text) !important;
}

.course-status-badge {
  border: 1px solid var(--course-line);
  background: var(--course-neutral-surface);
  color: var(--course-neutral-text) !important;
}

.course-status-badge.is-learned {
  border-color: rgba(39, 136, 152, 0.26);
  background: var(--course-accent-soft);
  color: var(--course-accent) !important;
}

.course-status-badge.is-review {
  border-color: rgba(184, 133, 36, 0.26);
  background: var(--course-warning-surface);
  color: var(--course-warning-text) !important;
}

.course-point-actions {
  display: grid;
  align-content: center;
  gap: 8px;
  min-width: 112px;
}

.course-point-actions button {
  background: var(--course-surface-solid);
  color: var(--bbs-shell-text) !important;
}

.course-empty {
  min-height: 140px;
  display: grid;
  place-items: center;
  padding: 24px;
  border: 1px dashed var(--course-line-strong);
  border-radius: 8px;
  color: var(--bbs-shell-muted) !important;
}

.course-point-modal {
  position: fixed;
  inset: 0;
  z-index: 500;
  display: grid;
  place-items: center;
  padding: 24px;
}

.course-modal-backdrop {
  position: absolute;
  inset: 0;
  background: var(--course-backdrop);
}

.course-modal-panel {
  position: relative;
  z-index: 1;
  width: min(720px, 100%);
  max-height: min(760px, calc(100dvh - 48px));
  display: grid;
  gap: 16px;
  overflow: auto;
  padding: 26px;
  border-radius: 8px;
  border: 1px solid var(--course-line);
  background: var(--course-surface-solid);
  color: var(--bbs-shell-text);
}

.course-modal-panel h2,
.knowledge-section h2,
.knowledge-section-head h2 {
  margin: 0;
  color: var(--bbs-shell-text) !important;
  font-size: 1.35rem;
  line-height: 1.25;
}

.course-modal-panel p {
  margin: 0;
  color: var(--bbs-shell-muted) !important;
}

.course-modal-close {
  position: absolute;
  top: 14px;
  right: 14px;
  width: 44px;
  height: 44px;
  border: 1px solid var(--course-line-strong);
  border-radius: 8px;
  background: var(--course-surface-soft);
  color: var(--bbs-shell-text);
  cursor: pointer;
}

.course-modal-meta {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px;
  margin: 0;
}

.course-modal-meta div {
  display: grid;
  gap: 4px;
  padding: 12px;
  border: 1px solid var(--course-line);
  border-radius: 8px;
  background: var(--course-surface-soft);
}

.course-modal-meta dt,
.course-resource-type {
  color: var(--course-accent) !important;
  font-family: var(--font-ui);
  font-size: 0.76rem;
  font-weight: 900;
  text-transform: uppercase;
}

.course-modal-meta dd {
  margin: 0;
}

.course-modal-resources,
.course-resource-list {
  display: grid;
  gap: 10px;
}

.course-resource-item {
  display: grid;
  gap: 5px;
  padding: 14px;
  border: 1px solid var(--course-line);
  border-radius: 8px;
  background: var(--course-surface-solid);
}

.course-resource-item strong {
  color: var(--bbs-shell-text) !important;
}

.course-resource-item small {
  color: var(--bbs-shell-muted) !important;
  line-height: 1.6;
}

.course-modal-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.course-modal-actions button {
  background: var(--course-surface-solid);
  color: var(--bbs-shell-text) !important;
}

.knowledge-shell {
  display: grid;
  grid-template-columns: 280px minmax(0, 1fr);
  gap: 18px;
  align-items: start;
}

.knowledge-sidebar {
  position: sticky;
  top: 116px;
  display: grid;
  gap: 14px;
  padding: 18px;
}

.knowledge-back {
  color: var(--course-accent) !important;
  font-weight: 900;
}

.knowledge-back::before {
  content: '← ';
}

.knowledge-list {
  display: grid;
  gap: 8px;
}

.knowledge-list-item {
  display: grid;
  gap: 8px;
  padding: 12px;
  min-height: 44px;
  border: 1px solid var(--course-line);
  border-radius: 8px;
  background: var(--course-surface-solid);
}

.knowledge-list-item.is-active {
  border-color: rgba(39, 136, 152, 0.34);
  background: var(--course-accent-soft);
}

.knowledge-list-item span:first-child {
  color: var(--bbs-shell-text) !important;
  font-weight: 900;
}

.knowledge-content {
  display: grid;
  gap: 16px;
  padding: 18px;
}

.knowledge-header {
  display: grid;
  gap: 12px;
  padding: 8px 4px 12px;
  border-bottom: 1px solid var(--course-line);
}

.knowledge-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.knowledge-actions button {
  background: var(--course-surface-solid);
  color: var(--bbs-shell-text) !important;
}

.knowledge-actions button.is-active {
  background: var(--course-primary);
  color: #ffffff !important;
}

.knowledge-section {
  display: grid;
  gap: 14px;
  padding: 20px;
  background: var(--course-surface-solid);
}

.knowledge-section-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}

.knowledge-section .discussion-markdown-body {
  color: var(--bbs-shell-text) !important;
}

.knowledge-section .discussion-markdown-body p,
.knowledge-section .discussion-markdown-body li {
  color: var(--bbs-shell-text) !important;
}

.knowledge-rag-thread {
  max-height: 420px;
  min-height: 220px;
  display: grid;
  align-content: start;
  gap: 10px;
  overflow: auto;
  padding: 12px;
  border: 1px solid var(--course-line);
  border-radius: 8px;
  background: var(--course-surface-soft);
}

.knowledge-rag-message {
  width: min(720px, 100%);
  display: grid;
  gap: 6px;
  padding: 12px;
  border: 1px solid var(--course-line);
  border-radius: 8px;
  background: var(--course-surface-solid);
}

.knowledge-rag-message.is-user {
  justify-self: end;
  background: var(--course-accent-soft);
}

.knowledge-rag-message.is-system {
  width: 100%;
  background: var(--course-warning-surface);
  color: var(--course-warning-text) !important;
}

.knowledge-rag-message strong {
  color: var(--course-accent) !important;
  font-family: var(--font-ui);
  font-size: 0.82rem;
}

.knowledge-rag-message .discussion-markdown-body {
  display: grid;
  gap: 8px;
}

.knowledge-rag-form {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 10px;
}

.knowledge-rag-form textarea {
  min-height: 84px;
  padding: 12px;
  resize: vertical;
}

.knowledge-rag-form button {
  align-self: stretch;
  min-width: 108px;
}

.knowledge-rag-form button:disabled {
  opacity: 0.64;
  cursor: not-allowed;
}

.knowledge-rag-status {
  min-height: 1.4em;
  margin: 0;
  color: var(--bbs-shell-muted) !important;
}

@media (max-width: 1100px) {
  .course-hero,
  .knowledge-shell {
    grid-template-columns: 1fr;
  }

  .knowledge-sidebar {
    position: static;
  }
}

@media (max-width: 760px) {
  .course-shell,
  .knowledge-shell {
    gap: 12px;
  }

  .course-hero,
  .course-overview,
  .course-toolbar,
  .course-point-card,
  .knowledge-sidebar,
  .knowledge-content,
  .knowledge-section {
    border: 0;
    border-radius: 0;
    background: transparent;
    box-shadow: none;
  }

  .course-hero,
  .course-overview,
  .course-toolbar,
  .course-point-card {
    padding: 16px 0;
    border-bottom: 1px solid var(--course-line);
  }

  .knowledge-sidebar {
    padding: 14px;
    border-radius: 8px;
    background: var(--course-surface-soft);
  }

  .knowledge-content {
    gap: 0;
    padding: 0;
  }

  .knowledge-header {
    padding: 16px 0;
  }

  .knowledge-section {
    padding: 18px 0;
  }

  .knowledge-section + .knowledge-section {
    border-top: 1px solid var(--course-line);
  }

  .course-overview,
  .course-point-card {
    display: grid;
    grid-template-columns: 1fr;
  }

  .course-modal-meta,
  .knowledge-rag-form {
    grid-template-columns: 1fr;
  }

  .course-progress {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 6px;
  }

  .course-progress span {
    min-height: 62px;
    align-content: center;
    justify-items: center;
    gap: 4px;
    padding: 9px 5px;
    border: 0;
    border-radius: 6px;
    text-align: center;
    font-size: clamp(0.66rem, 2.8vw, 0.78rem);
    line-height: 1.25;
  }

  .course-progress strong {
    font-size: clamp(1.25rem, 6vw, 1.6rem);
  }

  .course-overview .course-discussion-link {
    width: 100%;
  }

  .course-point-index {
    width: 54px;
    min-height: 40px;
  }

  .course-point-actions {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    min-width: 0;
  }

  .course-point-actions a,
  .course-point-actions button,
  .course-modal-actions a,
  .course-modal-actions button,
  .knowledge-actions a,
  .knowledge-actions button,
  .knowledge-section-head a,
  .knowledge-rag-form button {
    min-height: 44px;
  }

  .course-point-modal {
    place-items: end center;
    padding: calc(10px + env(safe-area-inset-top, 0px)) calc(10px + env(safe-area-inset-right, 0px))
      0 calc(10px + env(safe-area-inset-left, 0px));
  }

  .course-modal-panel {
    max-height: calc(100dvh - 10px - env(safe-area-inset-top, 0px));
    padding: 62px 16px max(18px, env(safe-area-inset-bottom, 0px));
    border-bottom: 0;
    border-radius: 12px 12px 0 0;
    overscroll-behavior: contain;
  }

  .course-modal-close {
    top: 10px;
    right: 10px;
    width: 44px;
    height: 44px;
  }

  .course-modal-meta div,
  .course-resource-item {
    border: 0;
    background: var(--course-surface-soft);
  }

  .knowledge-section-head {
    align-items: stretch;
    flex-direction: column;
  }

  .knowledge-rag-form button {
    min-height: 46px;
  }

  .knowledge-rag-thread {
    min-height: 190px;
    padding: 10px;
    border: 0;
  }

  .knowledge-rag-message {
    border: 0;
  }

  body.course-page .course-main .course-hero,
  body.course-page .course-main .course-overview,
  body.course-page .course-main .course-toolbar,
  body.course-page .course-main .course-point-card {
    border: 0 !important;
    border-bottom: 1px solid var(--course-line) !important;
    border-radius: 0 !important;
    background: transparent !important;
    box-shadow: none !important;
  }

  body.knowledge-page .knowledge-main .knowledge-sidebar {
    border: 0 !important;
    border-radius: 8px !important;
    background: var(--course-surface-soft) !important;
    box-shadow: none !important;
  }

  body.knowledge-page .knowledge-main .knowledge-content,
  body.knowledge-page .knowledge-main .knowledge-section {
    border: 0 !important;
    border-radius: 0 !important;
    background: transparent !important;
    box-shadow: none !important;
  }

  body.knowledge-page .knowledge-main .knowledge-section + .knowledge-section {
    border-top: 1px solid var(--course-line) !important;
  }
}

/* Formal knowledge reader: demo reading layout on the FREE-BBS dark palette. */
body.knowledge-page:has(.course-material-immersive) {
  background:
    radial-gradient(circle at 50% 0%, rgba(39, 136, 152, 0.12), transparent 40%),
    var(--bbs-shell-page);
}

body.knowledge-page:has(.course-material-immersive) .course-material-immersive {
  background: transparent;
}

.course-material-reader {
  width: min(100%, 960px);
  gap: 24px;
}

.course-material-context {
  min-width: 0;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  min-height: 28px;
}

.course-material-context .course-kicker {
  margin: 0;
}

.knowledge-status-badge {
  display: inline-flex;
  align-items: center;
  min-height: 28px;
  padding: 0 11px;
  border: 1px solid var(--course-line);
  border-radius: 999px;
  background: var(--course-neutral-surface);
  color: var(--course-neutral-text);
  font-family: var(--font-ui);
  font-size: 0.72rem;
  font-weight: 900;
}

.knowledge-status-badge.is-learned {
  border-color: rgba(120, 217, 198, 0.34);
  background: var(--course-accent-soft);
  color: var(--course-accent);
}

.knowledge-status-badge.is-review {
  border-color: rgba(229, 201, 109, 0.34);
  background: var(--course-warning-surface);
  color: var(--course-warning-text);
}

.course-material-header {
  min-width: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 28px;
  align-items: end;
  padding: 22px 0 28px;
  border-bottom-color: var(--course-line);
}

.course-material-heading {
  min-width: 0;
}

.course-material-header h1 {
  max-width: 820px;
  font-size: clamp(2.35rem, 6vw, 5rem);
  letter-spacing: -0.035em;
}

.course-material-header > .course-material-heading > p:last-child {
  max-width: 760px;
  margin: 16px 0 0;
  color: var(--bbs-shell-muted);
  font-size: 1rem;
  line-height: 1.85;
}

.knowledge-actions {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: 9px;
}

.knowledge-actions button {
  min-height: 42px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 7px;
  padding: 0 14px;
  border: 1px solid var(--course-line-strong);
  border-radius: 8px;
  background: var(--course-surface-solid);
  color: var(--bbs-shell-text) !important;
  font-family: var(--font-ui);
  font-size: 0.84rem;
  font-weight: 900;
  cursor: pointer;
  transition:
    border-color 160ms ease,
    background 160ms ease,
    color 160ms ease,
    transform 160ms ease;
}

.knowledge-actions button:hover,
.knowledge-actions button:focus-visible {
  border-color: var(--course-accent);
  transform: translateY(-1px);
}

.knowledge-actions button.is-active {
  border-color: var(--course-primary);
  background: var(--course-primary);
  color: #ffffff !important;
}

.course-material-section {
  min-width: 0;
  display: grid;
  gap: 22px;
  padding: clamp(20px, 4vw, 38px);
  border: 1px solid var(--course-line);
  border-radius: 14px;
  background: color-mix(in srgb, var(--course-surface-solid) 88%, transparent);
  box-shadow: 0 22px 60px rgba(1, 8, 11, 0.14);
}

.course-material-section-heading {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 18px;
  padding-bottom: 16px;
  border-bottom: 1px solid var(--course-line);
}

.course-material-section-heading .course-kicker {
  margin-bottom: 7px;
}

.course-material-section-heading h2 {
  margin: 0;
  color: var(--bbs-shell-text);
  font-size: 1.35rem;
  line-height: 1.2;
}

.course-material-section-note {
  color: var(--bbs-shell-muted);
  font-family: var(--font-ui);
  font-size: 0.72rem;
  font-weight: 800;
  white-space: nowrap;
}

.course-material-body {
  min-width: 0;
  min-height: 0;
  max-width: 820px;
  font-size: 1rem;
  line-height: 1.9;
}

.course-material-body h2,
.course-material-body h3,
.course-material-body h4 {
  margin: 2.1em 0 0.72em;
  color: var(--bbs-shell-text);
  line-height: 1.3;
}

.course-material-body h2 {
  padding-top: 0.35em;
  border-top: 1px solid var(--course-line);
  font-size: clamp(1.28rem, 2.4vw, 1.7rem);
}

.course-material-body h3 {
  font-size: 1.18rem;
}

.course-material-body p,
.course-material-body ul,
.course-material-body ol,
.course-material-body blockquote,
.course-material-body pre,
.course-material-body table {
  margin: 1.05em 0;
}

.course-material-body p,
.course-material-body li,
.course-material-body td,
.course-material-body th {
  color: var(--bbs-shell-text);
}

.course-material-body ul,
.course-material-body ol {
  padding-left: 1.45em;
}

.course-material-body li + li {
  margin-top: 0.42em;
}

.course-material-body strong {
  color: var(--bbs-shell-text);
}

.course-material-body blockquote {
  padding: 0.8em 1.05em;
  border-left: 3px solid var(--course-accent);
  background: var(--course-accent-soft);
  color: var(--bbs-shell-muted);
}

.course-material-body code {
  padding: 0.13em 0.36em;
  border: 1px solid var(--course-line);
  border-radius: 4px;
  background: rgba(0, 0, 0, 0.2);
  color: var(--course-accent);
  font-family: 'SFMono-Regular', Consolas, monospace;
  font-size: 0.88em;
}

.course-material-body pre {
  overflow: auto;
  padding: 16px 18px;
  border: 1px solid var(--course-line);
  border-radius: 9px;
  background: #071217;
}

.course-material-body pre code {
  padding: 0;
  border: 0;
  background: transparent;
  color: inherit;
}

.course-material-body .katex-display {
  margin: 1.65em 0;
  padding: 16px 12px;
  overflow-x: auto;
  overflow-y: hidden;
  border: 1px solid color-mix(in srgb, var(--course-accent) 22%, transparent);
  border-radius: 9px;
  background: color-mix(in srgb, var(--course-accent-soft) 52%, var(--course-surface-solid));
}

.course-material-body .katex {
  color: var(--bbs-shell-text);
}

.course-material-body img {
  max-width: 100%;
  height: auto;
  border-radius: 8px;
}

.knowledge-route-navigation {
  min-width: 0;
  position: relative;
  z-index: 1;
  display: grid;
  overflow: hidden;
  border: 1px solid var(--course-line-strong);
  border-radius: 16px;
  background: color-mix(in srgb, var(--course-surface-solid) 94%, transparent);
  box-shadow: 0 18px 46px rgba(1, 8, 11, 0.16);
}

.knowledge-route-header {
  min-width: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto auto;
  align-items: center;
  gap: 18px;
  padding: 13px 15px 11px;
  border-bottom: 1px solid var(--course-line);
}

.knowledge-route-header p,
.knowledge-route-header h2 {
  margin: 0;
}

.knowledge-route-header .course-kicker {
  margin-bottom: 4px;
  font-size: 0.58rem;
}

.knowledge-route-header h2 {
  color: var(--bbs-shell-text);
  font-size: 0.94rem;
  line-height: 1.2;
}

.knowledge-route-legend {
  display: flex;
  align-items: center;
  gap: 12px;
}

.knowledge-route-legend span {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  color: var(--bbs-shell-muted);
  font-size: 0.62rem;
  font-weight: 750;
  white-space: nowrap;
}

.knowledge-route-legend i {
  width: 20px;
  height: 0;
  border-top: 2px solid var(--course-accent);
}

.knowledge-route-legend i.is-related {
  border-top-style: dashed;
  opacity: 0.58;
}

.knowledge-route-discussion {
  min-height: 34px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0 11px;
  border: 1px solid color-mix(in srgb, var(--course-accent) 28%, var(--course-line));
  border-radius: 9px;
  background: var(--course-accent-soft);
  color: var(--course-accent) !important;
  font-size: 0.68rem;
  font-weight: 900;
  text-decoration: none;
  white-space: nowrap;
}

.knowledge-route-discussion:hover,
.knowledge-route-discussion:focus-visible {
  border-color: var(--course-accent);
  outline: none;
}

.knowledge-route-scroller {
  min-width: 0;
  overflow-x: auto;
  overflow-y: hidden;
  overscroll-behavior-x: contain;
  scrollbar-color: color-mix(in srgb, var(--course-accent) 30%, transparent) transparent;
  scrollbar-width: thin;
}

.knowledge-route-scroller:focus-visible {
  outline: 2px solid color-mix(in srgb, var(--course-accent) 58%, transparent);
  outline-offset: -2px;
}

.knowledge-route-scroller::-webkit-scrollbar {
  height: 7px;
}

.knowledge-route-scroller::-webkit-scrollbar-thumb {
  border: 2px solid transparent;
  border-radius: 999px;
  background: color-mix(in srgb, var(--course-accent) 34%, transparent);
  background-clip: padding-box;
}

.knowledge-route-canvas {
  position: relative;
  min-width: 100%;
  height: 158px;
  isolation: isolate;
  overflow: hidden;
  background:
    radial-gradient(
      circle at 50% 48%,
      color-mix(in srgb, var(--course-accent) 7%, transparent),
      transparent 52%
    ),
    linear-gradient(
      180deg,
      color-mix(in srgb, var(--course-surface-soft) 74%, transparent),
      transparent
    );
}

.knowledge-route-grid {
  position: absolute;
  inset: 0;
  z-index: 0;
  background-image:
    linear-gradient(
      to right,
      color-mix(in srgb, var(--course-accent) 7%, transparent) 1px,
      transparent 1px
    ),
    linear-gradient(
      to bottom,
      color-mix(in srgb, var(--course-accent) 7%, transparent) 1px,
      transparent 1px
    ),
    radial-gradient(
      circle,
      color-mix(in srgb, var(--course-accent) 13%, transparent) 1px,
      transparent 1.4px
    );
  background-size:
    80px 80px,
    80px 80px,
    20px 20px;
  opacity: 0.52;
  pointer-events: none;
  mask-image: linear-gradient(90deg, transparent, #000 7%, #000 93%, transparent);
}

.knowledge-route-edges {
  position: absolute;
  inset: 0;
  z-index: 1;
  overflow: visible;
  pointer-events: none;
}

.knowledge-route-edge,
.knowledge-route-edge-halo,
.knowledge-route-edge-pulse {
  fill: none;
  stroke-linecap: round;
  vector-effect: non-scaling-stroke;
}

.knowledge-route-edge-halo {
  stroke: var(--course-accent);
  stroke-width: 8;
  opacity: 0.07;
}

.knowledge-route-edge {
  stroke: var(--course-accent);
  stroke-width: 1.8;
  opacity: 0.76;
}

.knowledge-route-edge.is-related {
  stroke-dasharray: 5 7;
  stroke-width: 1.4;
  opacity: 0.46;
}

.knowledge-route-edge-halo.is-related {
  stroke-width: 5;
  opacity: 0.035;
}

.knowledge-route-edge-pulse {
  stroke: color-mix(in srgb, var(--course-accent) 78%, #ffffff);
  stroke-dasharray: 0.035 0.965;
  stroke-dashoffset: 0;
  stroke-width: 4;
  opacity: 0.78;
  filter: drop-shadow(0 0 4px var(--course-accent));
  animation: knowledge-route-signal 4s linear infinite;
  animation-delay: var(--route-edge-delay);
}

#knowledge-route-arrow path {
  fill: var(--course-accent);
}

@keyframes knowledge-route-signal {
  to {
    stroke-dashoffset: -1;
  }
}

.knowledge-route-node {
  position: absolute;
  z-index: 2;
  width: 152px;
  min-height: 62px;
  display: grid;
  grid-template-columns: 30px minmax(0, 1fr) 9px;
  align-items: center;
  gap: 8px;
  padding: 8px 9px;
  border: 1px solid var(--course-line);
  border-radius: 12px;
  background: color-mix(in srgb, var(--course-surface-solid) 92%, transparent);
  color: var(--bbs-shell-text) !important;
  box-shadow: 0 9px 24px rgba(1, 8, 11, 0.12);
  text-decoration: none;
  transform: translate(-50%, -50%);
  transition:
    border-color 160ms ease,
    background 160ms ease,
    box-shadow 160ms ease,
    transform 160ms ease;
}

a.knowledge-route-node:hover,
a.knowledge-route-node:focus-visible {
  z-index: 4;
  border-color: color-mix(in srgb, var(--course-accent) 55%, var(--course-line));
  background: color-mix(in srgb, var(--course-accent) 8%, var(--course-surface-solid));
  box-shadow: 0 14px 32px color-mix(in srgb, var(--course-accent) 15%, transparent);
  outline: none;
  transform: translate(-50%, calc(-50% - 3px));
}

.knowledge-route-node.is-current {
  z-index: 3;
  border-color: color-mix(in srgb, var(--course-accent) 68%, var(--course-line));
  background: color-mix(in srgb, var(--course-accent) 12%, var(--course-surface-solid));
  box-shadow:
    0 13px 32px color-mix(in srgb, var(--course-accent) 16%, transparent),
    0 0 0 3px color-mix(in srgb, var(--course-accent) 8%, transparent);
}

.knowledge-route-node-index {
  width: 30px;
  height: 30px;
  display: grid;
  place-items: center;
  border: 1px solid color-mix(in srgb, var(--course-accent) 22%, var(--course-line));
  border-radius: 9px;
  background: var(--course-accent-soft);
  color: var(--course-accent);
  font-family: 'SFMono-Regular', Consolas, monospace;
  font-size: 0.62rem;
  font-weight: 900;
}

.knowledge-route-node.is-current .knowledge-route-node-index {
  border-color: var(--course-accent);
  background: var(--course-primary);
  color: #ffffff;
}

.knowledge-route-node-copy {
  min-width: 0;
  display: grid;
  gap: 3px;
}

.knowledge-route-node-copy small {
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.knowledge-route-node-copy small {
  color: var(--bbs-shell-muted);
  font-family: 'SFMono-Regular', Consolas, monospace;
  font-size: 0.52rem;
  letter-spacing: 0.06em;
}

.knowledge-route-node-copy strong {
  display: -webkit-box;
  overflow: hidden;
  color: var(--bbs-shell-text);
  font-size: 0.7rem;
  line-height: 1.25;
  -webkit-box-orient: vertical;
  -webkit-line-clamp: 2;
}

.knowledge-route-node-state {
  width: 8px;
  height: 8px;
  border: 1px solid var(--course-line-strong);
  border-radius: 50%;
  background: var(--course-neutral-surface);
}

.knowledge-route-node.is-current .knowledge-route-node-state {
  border-color: var(--course-accent);
  background: var(--course-accent);
  box-shadow: 0 0 0 4px color-mix(in srgb, var(--course-accent) 10%, transparent);
}

.knowledge-route-node.is-learned .knowledge-route-node-state {
  border-color: #4ccba8;
  background: #4ccba8;
}

.knowledge-route-node.is-review .knowledge-route-node-state {
  border-color: var(--course-warning-text);
  background: var(--course-warning-text);
}

.knowledge-route-loading {
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  margin: 0;
  color: var(--bbs-shell-muted);
  font-size: 0.76rem;
}

.course-material-error {
  width: min(720px, calc(100% - 36px));
  min-height: 220px;
  margin: 120px auto 0;
  background: var(--course-surface-solid);
  color: var(--bbs-shell-muted);
}

.knowledge-chat {
  position: relative;
  z-index: 260;
}

.knowledge-chat-fab {
  position: fixed;
  right: max(22px, env(safe-area-inset-right));
  bottom: max(22px, env(safe-area-inset-bottom));
  z-index: 262;
  width: 60px;
  height: 60px;
  display: grid;
  place-items: center;
  padding: 0;
  border: 1px solid color-mix(in srgb, var(--course-accent) 44%, var(--course-line));
  border-radius: 50%;
  background: color-mix(in srgb, var(--course-primary) 90%, #071217);
  color: #ffffff;
  box-shadow:
    0 16px 38px rgba(1, 8, 11, 0.28),
    0 0 0 5px color-mix(in srgb, var(--course-accent) 9%, transparent);
  cursor: pointer;
  transition:
    border-color 180ms ease,
    box-shadow 180ms ease,
    transform 180ms ease;
}

.knowledge-chat-fab:hover,
.knowledge-chat-fab:focus-visible,
.knowledge-chat-fab.is-active {
  border-color: var(--course-accent);
  box-shadow:
    0 18px 44px rgba(1, 8, 11, 0.32),
    0 0 0 6px color-mix(in srgb, var(--course-accent) 14%, transparent),
    0 0 24px color-mix(in srgb, var(--course-accent) 24%, transparent);
  outline: none;
  transform: translateY(-2px);
}

.knowledge-chat-fab-orb {
  position: relative;
  width: 30px;
  height: 30px;
  display: grid;
  place-items: center;
  border: 1px solid rgba(255, 255, 255, 0.58);
  border-radius: 50%;
}

.knowledge-chat-fab-orb::before,
.knowledge-chat-fab-orb::after {
  content: '';
  position: absolute;
  border: 1px solid rgba(255, 255, 255, 0.42);
  border-radius: 50%;
}

.knowledge-chat-fab-orb::before {
  inset: 5px -5px;
  transform: rotate(42deg);
}

.knowledge-chat-fab-orb::after {
  inset: -5px 5px;
  transform: rotate(-42deg);
}

.knowledge-chat-fab-orb i {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: #ffffff;
  box-shadow: 0 0 10px #ffffff;
}

.knowledge-chat-fab-tooltip {
  position: absolute;
  top: 50%;
  right: calc(100% + 11px);
  width: max-content;
  padding: 7px 10px;
  border: 1px solid var(--course-line);
  border-radius: 8px;
  background: var(--course-surface-solid);
  color: var(--bbs-shell-text);
  font-size: 0.72rem;
  font-weight: 900;
  opacity: 0;
  pointer-events: none;
  transform: translate(6px, -50%);
  transition:
    opacity 160ms ease,
    transform 160ms ease;
}

.knowledge-chat-fab:hover .knowledge-chat-fab-tooltip,
.knowledge-chat-fab:focus-visible .knowledge-chat-fab-tooltip {
  opacity: 1;
  transform: translate(0, -50%);
}

.knowledge-chat-panel {
  position: fixed;
  right: max(22px, env(safe-area-inset-right));
  bottom: max(96px, calc(env(safe-area-inset-bottom) + 80px));
  z-index: 261;
  width: min(640px, calc(100vw - 44px));
  height: min(760px, calc(100dvh - 128px));
  min-height: min(520px, calc(100dvh - 128px));
  max-height: calc(100dvh - 128px);
  display: grid;
  grid-template-rows: auto auto minmax(0, 1fr);
  overflow: hidden;
  border: 1px solid var(--course-line-strong);
  border-radius: 22px;
  background: color-mix(in srgb, var(--course-surface-solid) 96%, transparent);
  color: var(--bbs-shell-text);
  box-shadow: 0 24px 70px rgba(1, 8, 11, 0.28);
  animation: knowledge-chat-enter 180ms ease-out;
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
}

.knowledge-chat-panel.hidden {
  display: none;
}

@keyframes knowledge-chat-enter {
  from {
    opacity: 0;
    transform: translateY(10px) scale(0.985);
  }

  to {
    opacity: 1;
    transform: translateY(0) scale(1);
  }
}

.knowledge-chat-header {
  display: grid;
  grid-template-columns: 44px minmax(0, 1fr) auto 34px;
  align-items: center;
  gap: 12px;
  padding: 17px 18px 15px;
  border-bottom: 1px solid var(--course-line);
}

.knowledge-chat-avatar {
  width: 44px;
  height: 44px;
  display: grid;
  place-items: center;
  border: 1px solid color-mix(in srgb, var(--course-accent) 42%, transparent);
  border-radius: 14px;
  background: var(--course-primary);
  color: #ffffff;
  font-family: var(--font-ui);
  font-size: 0.9rem;
  font-weight: 900;
  box-shadow: 0 0 18px color-mix(in srgb, var(--course-accent) 18%, transparent);
}

.knowledge-chat-header p,
.knowledge-chat-header h2 {
  margin: 0;
}

.knowledge-chat-header p {
  color: var(--course-accent);
  font-family: var(--font-ui);
  font-size: 0.62rem;
  font-weight: 900;
  letter-spacing: 0.13em;
  text-transform: uppercase;
}

.knowledge-chat-header h2 {
  margin-top: 3px;
  color: var(--bbs-shell-text);
  font-size: 1.08rem;
  line-height: 1.2;
}

.knowledge-chat-demo-badge {
  padding: 5px 9px;
  border: 1px solid var(--course-line);
  border-radius: 999px;
  background: var(--course-neutral-surface);
  color: var(--course-neutral-text);
  font-size: 0.64rem;
  font-weight: 800;
  white-space: nowrap;
}

.knowledge-chat-close {
  width: 34px;
  height: 34px;
  display: grid;
  place-items: center;
  padding: 0;
  border: 0;
  border-radius: 8px;
  background: transparent;
  color: var(--bbs-shell-muted);
  font-size: 1.35rem;
  cursor: pointer;
}

.knowledge-chat-close:hover,
.knowledge-chat-close:focus-visible {
  background: var(--course-neutral-surface);
  color: var(--bbs-shell-text);
  outline: none;
}

.knowledge-chat-tabs {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 6px;
  padding: 8px;
  border-bottom: 1px solid var(--course-line);
  background: color-mix(in srgb, var(--course-surface-soft) 72%, transparent);
}

.knowledge-chat-tab {
  min-width: 0;
  min-height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 8px 12px;
  border: 1px solid transparent;
  border-radius: 12px;
  background: transparent;
  color: var(--bbs-shell-muted);
  font-size: 0.82rem;
  font-weight: 850;
  cursor: pointer;
  transition:
    border-color 160ms ease,
    background 160ms ease,
    color 160ms ease;
}

.knowledge-chat-tab > span {
  color: var(--course-accent);
  font-size: 1rem;
  line-height: 1;
}

.knowledge-chat-tab small {
  min-width: 24px;
  padding: 3px 6px;
  border-radius: 999px;
  background: var(--course-neutral-surface);
  color: var(--course-neutral-text);
  font-size: 0.58rem;
  line-height: 1;
  text-align: center;
}

.knowledge-chat-tab:hover,
.knowledge-chat-tab:focus-visible {
  border-color: var(--course-line-strong);
  color: var(--bbs-shell-text);
  outline: none;
}

.knowledge-chat-tab.is-active {
  border-color: color-mix(in srgb, var(--course-accent) 30%, var(--course-line));
  background: var(--course-accent-soft);
  color: var(--bbs-shell-text);
  box-shadow: inset 0 -2px 0 color-mix(in srgb, var(--course-accent) 64%, transparent);
}

.knowledge-chat-tab.is-active small {
  background: color-mix(in srgb, var(--course-accent) 16%, var(--course-surface-solid));
  color: var(--course-accent);
}

.knowledge-chat-view {
  min-width: 0;
  min-height: 0;
  overflow: hidden;
}

.knowledge-chat-view.hidden,
.knowledge-chat-view[hidden] {
  display: none;
}

.knowledge-chat-max-view {
  display: grid;
  grid-template-rows: auto minmax(0, 1fr) auto auto auto;
}

.knowledge-chat-context {
  display: grid;
  gap: 4px;
  margin: 14px 16px 0;
  padding: 11px 13px;
  border: 1px solid color-mix(in srgb, var(--course-accent) 18%, var(--course-line));
  border-radius: 12px;
  background: var(--course-accent-soft);
}

.knowledge-chat-context span {
  color: var(--bbs-shell-muted);
  font-size: 0.64rem;
  font-weight: 800;
}

.knowledge-chat-context strong {
  overflow: hidden;
  color: var(--bbs-shell-text);
  font-size: 0.86rem;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.knowledge-chat-thread {
  min-height: 0;
  display: flex;
  flex-direction: column;
  gap: 14px;
  margin-top: 12px;
  padding: 5px 16px 15px;
  overflow-y: auto;
  overscroll-behavior: contain;
  scrollbar-width: thin;
}

.knowledge-chat-message {
  max-width: 86%;
  display: grid;
  gap: 5px;
  align-self: flex-start;
}

.knowledge-chat-message > span {
  color: var(--bbs-shell-muted);
  font-size: 0.64rem;
  font-weight: 800;
}

.knowledge-chat-message > p {
  margin: 0;
  padding: 12px 14px;
  border: 1px solid var(--course-line);
  border-radius: 6px 15px 15px;
  background: var(--course-surface-soft);
  color: var(--bbs-shell-text);
  font-size: 0.88rem;
  line-height: 1.7;
  white-space: pre-wrap;
}

.knowledge-chat-message.is-user {
  align-self: flex-end;
}

.knowledge-chat-message.is-user > span {
  text-align: right;
}

.knowledge-chat-message.is-user > p {
  border-color: color-mix(in srgb, var(--course-accent) 32%, transparent);
  border-radius: 15px 6px 15px 15px;
  background: var(--course-primary);
  color: #ffffff;
}

.knowledge-chat-prompts {
  display: flex;
  gap: 8px;
  padding: 0 16px 12px;
  overflow-x: auto;
}

.knowledge-chat-prompts button {
  min-height: 34px;
  flex: 0 0 auto;
  padding: 0 12px;
  border: 1px solid var(--course-line);
  border-radius: 999px;
  background: var(--course-surface-soft);
  color: var(--bbs-shell-text);
  font-size: 0.74rem;
  font-weight: 800;
  cursor: pointer;
}

.knowledge-chat-prompts button:hover,
.knowledge-chat-prompts button:focus-visible {
  border-color: var(--course-accent);
  color: var(--course-accent);
  outline: none;
}

.knowledge-chat-form {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  align-items: end;
  gap: 10px;
  margin: 0 16px;
  padding: 10px;
  border: 1px solid var(--course-line-strong);
  border-radius: 14px;
  background: var(--course-surface-soft);
}

.knowledge-chat-form textarea {
  width: 100%;
  min-height: 48px;
  max-height: 140px;
  resize: vertical;
  padding: 7px 5px;
  border: 0 !important;
  background: transparent !important;
  color: var(--bbs-shell-text) !important;
  font: inherit;
  font-size: 0.86rem;
  line-height: 1.55;
  outline: none;
}

.knowledge-chat-form textarea::placeholder {
  color: var(--bbs-shell-muted) !important;
}

.knowledge-chat-form button {
  min-width: 62px;
  min-height: 42px;
  padding: 0 13px;
  border: 0;
  border-radius: 10px;
  background: var(--course-primary);
  color: #ffffff;
  font-size: 0.78rem;
  font-weight: 900;
  cursor: pointer;
}

.knowledge-chat-privacy {
  margin: 8px 16px 12px;
  color: var(--bbs-shell-muted);
  font-size: 0.64rem;
  text-align: center;
}

.knowledge-discussion-view {
  display: grid;
  grid-template-rows: auto minmax(0, 1fr);
  background:
    linear-gradient(
      180deg,
      color-mix(in srgb, var(--course-accent) 5%, transparent),
      transparent 130px
    ),
    var(--course-surface-solid);
}

.knowledge-discussion-toolbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  padding: 15px 18px;
  border-bottom: 1px solid var(--course-line);
}

.knowledge-discussion-toolbar p,
.knowledge-discussion-toolbar h3 {
  margin: 0;
}

.knowledge-discussion-toolbar p {
  color: var(--course-accent);
  font-family: var(--font-ui);
  font-size: 0.6rem;
  font-weight: 900;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.knowledge-discussion-toolbar h3 {
  margin-top: 3px;
  color: var(--bbs-shell-text);
  font-size: 0.92rem;
}

.knowledge-discussion-toolbar-actions {
  display: flex;
  align-items: center;
  gap: 8px;
}

.knowledge-discussion-toolbar-actions button,
.knowledge-discussion-toolbar-actions a,
.knowledge-discussion-detail-actions button,
.knowledge-discussion-detail-actions a,
.knowledge-discussion-empty a {
  min-height: 32px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0 10px;
  border: 1px solid var(--course-line);
  border-radius: 9px;
  background: var(--course-surface-soft);
  color: var(--bbs-shell-text);
  font-size: 0.68rem;
  font-weight: 850;
  text-decoration: none;
  cursor: pointer;
}

.knowledge-discussion-toolbar-actions button:hover,
.knowledge-discussion-toolbar-actions button:focus-visible,
.knowledge-discussion-toolbar-actions a:hover,
.knowledge-discussion-toolbar-actions a:focus-visible,
.knowledge-discussion-detail-actions button:hover,
.knowledge-discussion-detail-actions button:focus-visible,
.knowledge-discussion-detail-actions a:hover,
.knowledge-discussion-detail-actions a:focus-visible,
.knowledge-discussion-empty a:hover,
.knowledge-discussion-empty a:focus-visible {
  border-color: var(--course-accent);
  color: var(--course-accent);
  outline: none;
}

.knowledge-discussion-toolbar-actions button:disabled {
  cursor: wait;
  opacity: 0.58;
}

.knowledge-discussion-list-view {
  min-height: 0;
  padding: 14px 16px 18px;
  overflow-y: auto;
  overscroll-behavior: contain;
  scrollbar-width: thin;
}

.knowledge-discussion-list-view.hidden,
.knowledge-discussion-list-view[hidden] {
  display: none;
}

.knowledge-discussion-status {
  margin: 0 0 10px;
  padding: 11px 13px;
  border: 1px solid var(--course-line);
  border-radius: 11px;
  background: var(--course-surface-soft);
  color: var(--bbs-shell-muted);
  font-size: 0.76rem;
  line-height: 1.5;
}

.knowledge-discussion-status.is-error {
  border-color: color-mix(in srgb, #e35c6f 38%, var(--course-line));
  background: color-mix(in srgb, #e35c6f 8%, var(--course-surface-soft));
  color: color-mix(in srgb, #e35c6f 74%, var(--bbs-shell-text));
}

.knowledge-discussion-list {
  display: grid;
  gap: 9px;
}

.knowledge-discussion-card {
  position: relative;
  width: 100%;
  min-width: 0;
  display: grid;
  grid-template-columns: 4px minmax(0, 1fr) auto;
  align-items: center;
  gap: 13px;
  padding: 13px 14px 13px 0;
  overflow: hidden;
  border: 1px solid var(--course-line);
  border-radius: 13px;
  background: color-mix(in srgb, var(--course-surface-soft) 88%, transparent);
  color: var(--bbs-shell-text);
  text-align: left;
  cursor: pointer;
  transition:
    border-color 160ms ease,
    background 160ms ease,
    box-shadow 160ms ease,
    transform 160ms ease;
}

.knowledge-discussion-card:hover,
.knowledge-discussion-card:focus-visible {
  border-color: color-mix(in srgb, var(--course-accent) 46%, var(--course-line));
  background: color-mix(in srgb, var(--course-accent) 7%, var(--course-surface-soft));
  box-shadow: 0 12px 28px color-mix(in srgb, var(--course-primary) 10%, transparent);
  outline: none;
  transform: translateY(-1px);
}

.knowledge-discussion-card-accent {
  width: 4px;
  height: calc(100% + 28px);
  background: color-mix(in srgb, var(--course-accent) 48%, var(--course-line));
}

.knowledge-discussion-card:hover .knowledge-discussion-card-accent,
.knowledge-discussion-card:focus-visible .knowledge-discussion-card-accent {
  background: var(--course-accent);
}

.knowledge-discussion-card-main {
  min-width: 0;
  display: grid;
  gap: 5px;
}

.knowledge-discussion-card-topline {
  min-width: 0;
  display: flex;
  align-items: center;
  gap: 7px;
  color: var(--bbs-shell-muted);
  font-size: 0.62rem;
  font-weight: 800;
}

.knowledge-discussion-badges {
  display: flex;
  align-items: center;
  gap: 5px;
}

.knowledge-discussion-badges:empty {
  display: none;
}

.knowledge-discussion-badges span {
  padding: 3px 6px;
  border-radius: 999px;
  font-size: 0.56rem;
  font-weight: 900;
  line-height: 1;
}

.knowledge-discussion-badges .is-pinned {
  background: color-mix(in srgb, var(--course-accent) 14%, var(--course-surface-solid));
  color: var(--course-accent);
}

.knowledge-discussion-badges .is-featured {
  background: color-mix(in srgb, #d99b30 14%, var(--course-surface-solid));
  color: var(--course-warning-text);
}

.knowledge-discussion-card-main > strong {
  overflow: hidden;
  color: var(--bbs-shell-text);
  font-size: 0.86rem;
  line-height: 1.35;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.knowledge-discussion-card-meta {
  overflow: hidden;
  color: var(--bbs-shell-muted);
  font-size: 0.66rem;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.knowledge-discussion-card-stats {
  display: grid;
  grid-template-columns: repeat(2, auto) 22px;
  align-items: center;
  gap: 8px;
  color: var(--bbs-shell-muted);
  font-size: 0.61rem;
  font-weight: 750;
  white-space: nowrap;
}

.knowledge-discussion-card-stats i {
  color: var(--course-accent);
  font-size: 1rem;
  font-style: normal;
  text-align: right;
}

.knowledge-discussion-empty {
  min-height: 310px;
  display: grid;
  place-items: center;
  align-content: center;
  gap: 8px;
  padding: 28px;
  border: 1px dashed var(--course-line-strong);
  border-radius: 14px;
  background: var(--course-surface-soft);
  color: var(--bbs-shell-muted);
  text-align: center;
}

.knowledge-discussion-empty > span {
  color: var(--course-accent);
  font-size: 2.1rem;
}

.knowledge-discussion-empty strong {
  color: var(--bbs-shell-text);
  font-size: 0.92rem;
}

.knowledge-discussion-empty p {
  max-width: 340px;
  margin: 0 0 6px;
  font-size: 0.76rem;
  line-height: 1.6;
}

.knowledge-discussion-detail {
  min-height: 0;
  padding: 16px 19px 20px;
  overflow-y: auto;
  overscroll-behavior: contain;
  scrollbar-width: thin;
}

.knowledge-discussion-detail.hidden,
.knowledge-discussion-detail[hidden] {
  display: none;
}

.knowledge-discussion-detail-actions {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  margin-bottom: 18px;
}

.knowledge-discussion-detail-heading {
  padding-bottom: 16px;
  border-bottom: 1px solid var(--course-line);
}

.knowledge-discussion-detail-heading h3 {
  margin: 8px 0 7px;
  color: var(--bbs-shell-text);
  font-size: 1.18rem;
  line-height: 1.35;
}

.knowledge-discussion-detail-heading p {
  margin: 0;
  color: var(--bbs-shell-muted);
  font-size: 0.72rem;
}

.knowledge-discussion-detail-body {
  min-height: 180px;
  padding: 18px 0 8px;
  color: var(--bbs-shell-text) !important;
  font-size: 0.86rem;
  line-height: 1.72;
  overflow-wrap: anywhere;
}

.knowledge-discussion-detail-body :where(p, li, strong, h1, h2, h3, h4) {
  color: var(--bbs-shell-text) !important;
}

.knowledge-discussion-detail-body .katex-display {
  max-width: 100%;
  overflow-x: auto;
  overflow-y: hidden;
}

.knowledge-discussion-detail-stats {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  padding-top: 13px;
  border-top: 1px solid var(--course-line);
}

.knowledge-discussion-detail-stats span {
  padding: 6px 8px;
  border-radius: 8px;
  background: var(--course-neutral-surface);
  color: var(--bbs-shell-muted);
  font-size: 0.66rem;
}

.knowledge-discussion-detail-stats strong {
  color: var(--bbs-shell-text);
}

.knowledge-discussion-loading {
  display: grid;
  gap: 10px;
  padding-top: 4px;
}

.knowledge-discussion-loading span {
  height: 12px;
  border-radius: 999px;
  background: linear-gradient(
    90deg,
    var(--course-neutral-surface),
    color-mix(in srgb, var(--course-accent) 11%, var(--course-neutral-surface)),
    var(--course-neutral-surface)
  );
  background-size: 220% 100%;
  animation: knowledge-discussion-loading 1.2s ease-in-out infinite;
}

.knowledge-discussion-loading span:nth-child(2) {
  width: 86%;
}

.knowledge-discussion-loading span:nth-child(3) {
  width: 68%;
}

@keyframes knowledge-discussion-loading {
  from {
    background-position: 100% 0;
  }

  to {
    background-position: -100% 0;
  }
}

@media (max-width: 720px) {
  .course-material-header {
    grid-template-columns: minmax(0, 1fr);
    gap: 18px;
  }

  .knowledge-actions {
    min-width: 0;
    justify-content: flex-start;
  }

  .knowledge-actions button {
    flex: 1 1 140px;
  }

  .course-material-section-heading {
    align-items: flex-start;
    flex-direction: column;
    gap: 8px;
  }

  .course-material-section-note {
    white-space: normal;
  }
}

@media (max-width: 520px) {
  .course-material-immersive {
    padding-right: 16px;
    padding-bottom: 90px;
    padding-left: 16px;
  }

  .course-material-context {
    align-items: flex-start;
    flex-direction: column;
    gap: 8px;
  }

  .course-material-header h1 {
    font-size: clamp(2.1rem, 12vw, 3.3rem);
  }

  .course-material-section {
    padding: 20px 16px;
    border-radius: 10px;
  }

  .course-material-back {
    width: 44px;
    padding: 0;
  }

  .course-material-back strong {
    display: none;
  }

  .knowledge-route-navigation {
    border-radius: 13px;
  }

  .knowledge-route-header {
    grid-template-columns: minmax(0, 1fr) auto;
    gap: 10px;
    padding: 10px 11px 9px;
  }

  .knowledge-route-header h2 {
    font-size: 0.84rem;
  }

  .knowledge-route-legend {
    display: none;
  }

  .knowledge-route-discussion {
    min-height: 32px;
    padding: 0 9px;
    font-size: 0.64rem;
  }

  .knowledge-chat-fab {
    right: max(14px, env(safe-area-inset-right));
    bottom: max(14px, env(safe-area-inset-bottom));
    width: 54px;
    height: 54px;
  }

  .knowledge-chat-fab.is-active {
    opacity: 0;
    pointer-events: none;
    transform: scale(0.84);
  }

  .knowledge-chat-panel {
    right: 12px;
    left: 12px;
    bottom: max(12px, env(safe-area-inset-bottom));
    width: auto;
    height: calc(100dvh - 24px);
    min-height: 0;
    max-height: calc(100dvh - 24px);
    border-radius: 16px;
  }

  .knowledge-chat-header {
    grid-template-columns: 40px minmax(0, 1fr) 32px;
    gap: 9px;
    padding-top: 13px;
    padding-bottom: 12px;
    padding-right: 10px;
    padding-left: 10px;
  }

  .knowledge-chat-avatar {
    width: 40px;
    height: 40px;
  }

  .knowledge-chat-demo-badge {
    display: none;
  }

  .knowledge-chat-tabs {
    padding: 7px;
  }

  .knowledge-chat-tab {
    min-height: 42px;
    gap: 6px;
    padding-right: 8px;
    padding-left: 8px;
    font-size: 0.76rem;
  }

  .knowledge-chat-context {
    margin-right: 12px;
    margin-left: 12px;
  }

  .knowledge-chat-thread {
    padding-right: 12px;
    padding-left: 12px;
  }

  .knowledge-chat-prompts {
    padding-right: 12px;
    padding-left: 12px;
  }

  .knowledge-chat-form {
    margin-right: 12px;
    margin-left: 12px;
  }

  .knowledge-discussion-toolbar {
    align-items: flex-start;
    flex-direction: column;
    gap: 10px;
    padding: 12px;
  }

  .knowledge-discussion-toolbar-actions {
    width: 100%;
  }

  .knowledge-discussion-toolbar-actions a {
    flex: 1;
  }

  .knowledge-discussion-list-view {
    padding: 11px 12px 15px;
  }

  .knowledge-discussion-card {
    grid-template-columns: 4px minmax(0, 1fr);
    gap: 11px;
    padding-top: 12px;
    padding-bottom: 12px;
  }

  .knowledge-discussion-card-stats {
    grid-column: 2;
    grid-template-columns: repeat(2, auto) 1fr;
    justify-content: start;
  }

  .knowledge-discussion-card-stats i {
    text-align: right;
  }

  .knowledge-discussion-detail {
    padding: 13px 14px 18px;
  }

  .knowledge-discussion-detail-heading h3 {
    font-size: 1.08rem;
  }

  .knowledge-chat-fab-tooltip {
    display: none;
  }
}

@media (prefers-reduced-motion: reduce) {
  .knowledge-chat-panel {
    animation: none;
  }

  .knowledge-chat-fab,
  .knowledge-chat-fab-tooltip {
    transition: none;
  }

  .knowledge-discussion-loading span {
    animation: none;
  }

  .knowledge-route-edge-pulse {
    display: none;
    animation: none;
  }
}

/* Final placement overrides for the knowledge workspace. */
.course-material-immersive {
  padding: 72px 24px 36px;
}

.knowledge-tools {
  position: fixed;
  top: 72px;
  bottom: 24px;
  left: max(24px, calc((100vw - 1840px) / 2));
  width: var(--knowledge-tools-width);
  height: auto;
}

.knowledge-workbench .course-material-reader {
  width: 100%;
  max-width: none;
  min-width: 0;
  gap: 24px;
  margin: 0;
}

.knowledge-workbench .course-material-body {
  max-width: none;
}

.knowledge-chat {
  min-width: 0;
  position: fixed;
  top: 72px;
  right: max(24px, calc((100vw - 1840px) / 2));
  bottom: 24px;
  z-index: 260;
  width: var(--knowledge-interaction-width);
  height: auto;
  display: none;
}

.knowledge-panel-resizer {
  grid-column: 3;
  position: fixed;
  top: 72px;
  right: calc(max(24px, calc((100vw - 1840px) / 2)) + var(--knowledge-interaction-width) + 12px);
  bottom: 24px;
  width: 8px;
  height: auto;
}

.knowledge-workbench.is-interaction-open .knowledge-chat {
  display: block;
}

.knowledge-chat-panel {
  position: static;
  inset: auto;
  width: 100%;
  height: 100%;
  min-height: 0;
  max-height: none;
  border-radius: 16px;
  box-shadow: 0 18px 54px rgba(1, 8, 11, 0.2);
  animation: knowledge-chat-side-enter 180ms ease-out;
}

.knowledge-chat-fab.is-active {
  opacity: 1;
  pointer-events: auto;
  transform: none;
}

@media (max-width: 920px) {
  .course-material-immersive {
    padding-right: 14px;
    padding-left: 14px;
  }

  .knowledge-chat,
  .knowledge-workbench.is-interaction-open .knowledge-chat {
    position: fixed;
    inset: 0 0 0 auto;
    z-index: 280;
    width: min(92vw, 520px);
    height: 100dvh;
  }

  .knowledge-chat-panel {
    width: 100%;
    height: 100dvh;
    border-radius: 16px 0 0 16px;
  }

  .knowledge-tools {
    top: 72px;
    bottom: 24px;
    left: 14px;
    width: 62px;
  }
}

@media (max-width: 620px) {
  .course-material-immersive {
    padding: 72px 10px 92px;
  }

  .knowledge-chat,
  .knowledge-workbench.is-interaction-open .knowledge-chat {
    width: 100vw;
  }

  .knowledge-chat-panel {
    border-radius: 0;
  }

  .knowledge-tools {
    top: 72px;
    right: auto;
    bottom: 12px;
    left: 10px;
    width: 54px;
  }
}