:root {
  --bg-1: #02040c;
  --bg-2: #07111f;
  --panel: rgba(7, 16, 30, 0.7);
  --panel-strong: rgba(9, 18, 33, 0.84);
  --border: rgba(144, 179, 255, 0.22);
  --text: #edf4ff;
  --muted: rgba(224, 234, 255, 0.74);
  --accent: #7eb9ff;
  --accent-warm: #ffb76a;
  --accent-green: #8fefcf;
  --shadow: 0 24px 54px rgba(0, 0, 0, 0.34);
}

* {
  box-sizing: border-box;
}

html,
body {
  height: 100%;
}

body {
  margin: 0;
  font-family: "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  color: var(--text);
  background:
    radial-gradient(circle at 18% 10%, rgba(89, 118, 255, 0.16), transparent 22%),
    radial-gradient(circle at 86% 12%, rgba(255, 179, 93, 0.12), transparent 20%),
    radial-gradient(circle at 50% 85%, rgba(54, 102, 176, 0.1), transparent 26%),
    linear-gradient(180deg, var(--bg-1) 0%, var(--bg-2) 100%);
  overflow: hidden;
}

.planetarium-page {
  position: relative;
  width: 100vw;
  height: 100vh;
}

#spaceCanvas {
  display: block;
  width: 100%;
  height: 100%;
}

.topbar,
.legend-panel,
.bottom-ui {
  position: absolute;
  z-index: 2;
}

.topbar {
  top: 18px;
  left: 22px;
  right: 22px;
  display: flex;
  justify-content: space-between;
  gap: 18px;
  align-items: flex-start;
}

.brand-group,
.control-group {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  align-items: center;
}

.back-link,
.page-tag,
.control-btn,
.control-select,
.legend-panel,
.info-card,
.mission-card {
  backdrop-filter: blur(16px);
  background: var(--panel);
  border: 1px solid var(--border);
  box-shadow: var(--shadow);
}

.back-link,
.page-tag {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  padding: 0 16px;
  border-radius: 999px;
  color: var(--text);
  text-decoration: none;
  font-weight: 700;
}

.page-tag {
  color: #ffd59e;
}

.control-btn,
.control-select,
.preset-chip,
.mission-btn {
  appearance: none;
  border: 1px solid var(--border);
  border-radius: 14px;
  color: var(--text);
  background: rgba(10, 19, 34, 0.84);
  font-size: 0.95rem;
  cursor: pointer;
  transition: transform 160ms ease, border-color 160ms ease, background 160ms ease;
}

.control-btn:hover,
.control-select:hover,
.preset-chip:hover,
.mission-btn:hover {
  transform: translateY(-1px);
  border-color: rgba(173, 200, 255, 0.36);
}

.control-btn {
  padding: 12px 14px;
}

.control-btn.primary {
  background: linear-gradient(135deg, rgba(108, 157, 255, 0.96), rgba(72, 120, 232, 0.96));
}

.control-select {
  min-height: 46px;
  padding: 0 14px;
}

.legend-panel {
  top: 92px;
  left: 22px;
  width: min(430px, calc(100vw - 44px));
  padding: 18px 18px 20px;
  border-radius: 24px;
}

.legend-title,
.mini-title {
  font-size: 0.82rem;
  font-weight: 800;
  letter-spacing: 0.08em;
  color: #ffc983;
  text-transform: uppercase;
}

.legend-panel p,
.info-card p,
.mission-card p {
  margin: 10px 0 0;
  color: var(--muted);
  line-height: 1.68;
}

.preset-wrap,
.timeline-wrap,
.interaction-guide {
  margin-top: 18px;
}

.preset-wrap label,
.timeline-topline label,
.timeline-topline span,
.slider-grid label,
.slider-grid span {
  color: rgba(235, 243, 255, 0.88);
  font-size: 0.92rem;
}

.preset-grid,
.mission-list {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 10px;
}

.preset-chip,
.mission-btn {
  padding: 10px 14px;
}

.preset-chip.active,
.mission-btn.active {
  background: linear-gradient(135deg, rgba(255, 186, 104, 0.98), rgba(255, 131, 88, 0.95));
  border-color: rgba(255, 188, 132, 0.48);
  color: #111420;
  font-weight: 800;
}

.slider-grid {
  margin-top: 18px;
  display: grid;
  grid-template-columns: auto minmax(120px, 1fr) auto;
  gap: 12px;
  align-items: center;
}

.slider-grid input[type="range"],
.timeline-wrap input[type="range"] {
  width: 100%;
}

.slider-grid input[type="range"] {
  accent-color: var(--accent);
}

.timeline-topline {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  align-items: center;
}

.timeline-wrap input[type="range"] {
  margin-top: 10px;
  accent-color: var(--accent-warm);
}

.interaction-guide {
  display: grid;
  gap: 10px;
}

.guide-item {
  display: flex;
  justify-content: space-between;
  gap: 14px;
  padding: 12px 14px;
  border-radius: 16px;
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid rgba(160, 186, 245, 0.14);
}

.guide-item strong {
  color: #fff0d6;
}

.guide-item span {
  color: var(--muted);
  text-align: right;
}

.bottom-ui {
  left: 22px;
  right: 22px;
  bottom: 22px;
  display: flex;
  justify-content: space-between;
  gap: 18px;
  pointer-events: none;
}

.info-card,
.mission-card {
  width: min(360px, calc(50vw - 31px));
  padding: 18px 20px 20px;
  border-radius: 24px;
  pointer-events: auto;
}

.info-card {
  background: var(--panel-strong);
}

.info-card h2 {
  margin: 10px 0 8px;
  font-size: clamp(1.8rem, 3vw, 2.4rem);
}

.info-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
  margin: 16px 0 0;
}

.info-grid div {
  padding: 12px;
  border-radius: 16px;
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid rgba(160, 186, 245, 0.14);
}

.info-grid dt {
  font-size: 0.82rem;
  color: rgba(226, 236, 255, 0.6);
}

.info-grid dd {
  margin: 8px 0 0;
  font-weight: 700;
}

.mission-card {
  align-self: flex-end;
}

.mission-list {
  margin-top: 12px;
}

.mission-btn {
  width: 100%;
  text-align: left;
}

@media (max-width: 1120px) {
  body {
    overflow: auto;
  }

  .planetarium-page {
    min-height: 100vh;
    height: auto;
  }

  #spaceCanvas {
    position: fixed;
    inset: 0;
  }

  .topbar,
  .legend-panel,
  .bottom-ui {
    position: relative;
  }

  .topbar {
    top: auto;
    left: auto;
    right: auto;
    padding: 18px 18px 0;
  }

  .legend-panel {
    top: auto;
    left: auto;
    width: auto;
    margin: 12px 18px 0;
  }

  .bottom-ui {
    left: auto;
    right: auto;
    bottom: auto;
    padding: 18px;
    flex-direction: column;
    pointer-events: auto;
  }

  .info-card,
  .mission-card {
    width: auto;
  }
}

@media (max-width: 640px) {
  .topbar {
    gap: 12px;
  }

  .control-group {
    gap: 8px;
  }

  .control-btn,
  .control-select,
  .preset-chip,
  .mission-btn {
    width: 100%;
  }

  .slider-grid {
    grid-template-columns: 1fr;
  }

  .guide-item {
    flex-direction: column;
  }

  .guide-item span {
    text-align: left;
  }
}