/* The course track and its nodes share one ellipse. Keep the island clear in its centre. */
body.world-page .island-course-stage {
  display: block;
  min-height: 100dvh;
  padding: 96px clamp(14px, 2.4vw, 36px) 38px;
  overflow: visible;
  animation: none;
}

body.world-page .island-course-stage > header {
  display: block;
  width: min(100%, 1260px);
  margin: 0 auto 12px;
  text-align: left;
}

body.world-page .island-course-back {
  position: fixed;
  z-index: 45;
  top: 16px;
  left: calc(var(--bbs-shell-width, 216px) + 16px);
  min-height: 48px;
  padding: 10px 16px;
  box-shadow: 0 6px 18px rgba(5, 30, 38, 0.12);
}

.island-course-heading {
  display: grid;
  gap: 10px;
}

#island-course-title:focus {
  outline: none;
}

.island-course-system {
  --course-planet-size: clamp(120px, 12vw, 160px);
  position: relative;
  width: min(100%, 1260px);
  height: 1000px;
  margin: 0 auto;
  isolation: isolate;
  touch-action: pan-y pinch-zoom;
}

body.world-page .island-course-orbit {
  position: absolute;
  inset: 0;
  display: block;
  width: 100%;
  height: 100%;
  min-height: 0;
  padding: 0;
  margin: 0;
  perspective: none;
  transform-style: flat;
  pointer-events: none;
}

body.world-page .island-course-orbit::before {
  content: none;
}

body.world-page .island-course-orbit::after {
  top: 46%;
  left: 50%;
  width: calc(100% - 280px);
  height: 68%;
  aspect-ratio: auto;
  transform: translate(-50%, -50%);
  animation: none;
  background: none;
  border: 1px solid var(--world-orbit-line);
  box-shadow: 0 0 24px var(--world-orbit-line-soft);
}

.island-course-hub {
  position: absolute;
  z-index: 3;
  top: 46%;
  left: 50%;
  width: min(400px, calc(100% - var(--course-planet-size) - 300px));
  aspect-ratio: 1;
  padding: 0;
  border: 0;
  border-radius: 50%;
  background: none;
  transform: translate(-50%, -50%);
  cursor: pointer;
}

.island-course-hub img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: contain;
  filter: drop-shadow(0 20px 22px rgba(6, 34, 43, 0.26));
  pointer-events: none;
}

.island-course-hub:focus-visible,
.island-course-control:focus-visible {
  outline: 3px solid var(--world-orbit-focus);
  outline-offset: 6px;
}

.island-course-hub[aria-pressed='true'] {
  outline: 2px dashed var(--world-orbit-focus);
  outline-offset: 10px;
}

body.world-page .island-course-node:nth-child(n) {
  position: absolute;
  width: var(--course-planet-size);
  top: var(--course-track-y, 46%);
  left: var(--course-track-x, calc(100% - 140px));
  z-index: 4;
  margin: 0;
  transform: translate(-50%, -50%);
  animation: none;
  opacity: 1;
  pointer-events: auto;
  transition:
    left 520ms ease,
    top 520ms ease;
}

.island-course-node[data-course-slot='0'] {
  --course-track-x: calc(100% - 140px);
  --course-track-y: 46%;
}

.island-course-node[data-course-slot='1'] {
  --course-track-x: calc(75% - 70px);
  --course-track-y: 75.4449%;
}

.island-course-node[data-course-slot='2'] {
  --course-track-x: calc(25% + 70px);
  --course-track-y: 75.4449%;
}

.island-course-node[data-course-slot='3'] {
  --course-track-x: 140px;
  --course-track-y: 46%;
}

.island-course-node[data-course-slot='4'] {
  --course-track-x: calc(25% + 70px);
  --course-track-y: 16.5551%;
}

.island-course-node[data-course-slot='5'] {
  --course-track-x: calc(75% - 70px);
  --course-track-y: 16.5551%;
}

body.world-page .island-course-planet > .island-course-identity {
  top: calc(100% - 8px);
  bottom: auto;
  width: 218px;
  padding: 12px;
}

/* The far arc has compact labels above the planets, never across the central island. */
body.world-page
  .island-course-node:is([data-course-slot='4'], [data-course-slot='5'])
  .island-course-identity {
  top: auto;
  bottom: calc(100% - 8px);
}

.island-course-node:is([data-course-slot='4'], [data-course-slot='5'])
  .island-course-identity
  > span {
  display: none;
}

.island-course-control {
  position: absolute;
  z-index: 8;
  top: 46%;
  display: grid;
  place-items: center;
  width: 46px;
  height: 46px;
  padding: 0;
  border: 1px solid var(--world-orbit-line);
  border-radius: 50%;
  background: var(--world-orbit-control);
  color: var(--world-paper);
  font: 700 30px/1 var(--font-zh-ui);
  transform: translateY(-50%);
  cursor: pointer;
}

.island-course-control[data-course-step='-1'] {
  left: 0;
}

.island-course-control[data-course-step='1'] {
  right: 0;
}

body.world-page .island-course-instruction,
body.world-page .island-course-status {
  max-width: 1120px;
  margin: 8px auto 0;
  color: var(--world-muted) !important;
  font-family: var(--font-zh-body);
  font-weight: var(--font-zh-body-weight, 400);
  font-size: max(15px, 0.85rem);
  line-height: 1.6;
  text-align: center;
}

@media (max-width: 900px) {
  .island-course-system {
    height: 900px;
  }

  body.world-page .island-course-back {
    left: 14px;
  }

  body.world-page .island-course-stage {
    padding-bottom: calc(132px + env(safe-area-inset-bottom, 0px));
  }
}

@media (max-width: 640px) {
  body.world-page .island-course-stage {
    padding-top: 150px;
  }

  body.world-page .island-course-stage > header {
    text-align: left;
  }

  body.world-page .island-course-back {
    top: 78px;
    min-height: 44px;
  }

  .island-course-system {
    --course-planet-size: 96px;
    height: 1100px;
  }

  .island-course-hub {
    top: 48%;
    width: min(66vw, 250px);
  }

  body.world-page .island-course-orbit::after {
    top: 48%;
    width: calc(100% - 110px);
    height: 700px;
  }

  /* A taller ellipse with a 30-degree phase keeps every stop clear of the island on phones. */
  .island-course-node[data-course-slot='0'] {
    --course-track-x: calc(93.3013% - 47.6314px);
    --course-track-y: calc(48% + 175px);
  }

  .island-course-node[data-course-slot='1'] {
    --course-track-x: 50%;
    --course-track-y: calc(48% + 350px);
  }

  .island-course-node[data-course-slot='2'] {
    --course-track-x: calc(6.6987% + 47.6314px);
    --course-track-y: calc(48% + 175px);
  }

  .island-course-node[data-course-slot='3'] {
    --course-track-x: calc(6.6987% + 47.6314px);
    --course-track-y: calc(48% - 175px);
  }

  .island-course-node[data-course-slot='4'] {
    --course-track-x: 50%;
    --course-track-y: calc(48% - 350px);
  }

  .island-course-node[data-course-slot='5'] {
    --course-track-x: calc(93.3013% - 47.6314px);
    --course-track-y: calc(48% - 175px);
  }

  body.world-page .island-course-planet > .island-course-identity {
    width: 190px;
    padding: 10px;
  }

  body.world-page
    .island-course-node:is([data-course-slot='0'], [data-course-slot='5'])
    .island-course-identity {
    left: auto;
    right: 0;
    transform: none;
  }

  body.world-page
    .island-course-node:is([data-course-slot='2'], [data-course-slot='3'])
    .island-course-identity {
    left: 0;
    transform: none;
  }

  body.world-page .island-course-node[data-course-slot='3'] .island-course-identity {
    top: auto;
    bottom: calc(100% - 8px);
  }

  .island-course-node[data-course-slot='3'] .island-course-identity > span {
    display: none;
  }

  .island-course-control {
    top: 48%;
    width: 42px;
    height: 42px;
  }
}

@media (prefers-reduced-motion: reduce) {
  body.world-page .island-course-node:nth-child(n) {
    transition: none;
  }
}