/* ─────────────────────────────────────────────────────────
   Shared design system for the solar-system scenes.
   Page-specific rules stay in each page's own <style> block.
   ───────────────────────────────────────────────────────── */
:root {
  --bg: #050810;
  --ink: #e8ecf4;
  --ink-dim: #8893a8;
  --ink-faint: #707b91;
  --accent: #f4c560;
  --accent-warm: #e89248;
  --accent-cool: #6ab0ff;
  --line: rgba(232, 236, 244, 0.08);
  --panel: rgba(8, 12, 22, 0.72);
  --panel-bright: rgba(15, 22, 38, 0.85);
}

* { box-sizing: border-box; margin: 0; padding: 0; }

button:focus-visible,
a:focus-visible,
input:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
}

html, body {
  height: 100%;
  overflow: hidden;
  background: var(--bg);
  color: var(--ink);
  font-family: 'Newsreader', Georgia, serif;
  font-feature-settings: 'ss01', 'ss02';
  -webkit-font-smoothing: antialiased;
}

#canvas-container { position: fixed; inset: 0; z-index: 0; }
canvas { display: block; }

/* ──── Header ──── */
.header {
  position: fixed;
  top: 0; left: 0; right: 0;
  padding: 24px 32px;
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  z-index: 10;
  pointer-events: none;
}
.title { font-size: 22px; font-weight: 400; letter-spacing: 0.02em; line-height: 1.1; }
.title em { font-style: italic; color: var(--accent); }
.subtitle {
  font-family: 'Fragment Mono', monospace;
  font-size: 10px; letter-spacing: 0.18em; text-transform: uppercase;
  color: var(--ink-dim); margin-top: 6px;
}
.nav-link, .back-link {
  display: inline-block; margin-top: 10px;
  font-family: 'Fragment Mono', monospace;
  font-size: 9px; letter-spacing: 0.18em; text-transform: uppercase;
  color: var(--ink-dim); text-decoration: none; pointer-events: auto;
  border-bottom: 1px solid transparent; padding-bottom: 2px;
  transition: color 0.2s, border-color 0.2s;
}
.nav-link:hover, .back-link:hover { color: var(--accent); border-color: rgba(244, 197, 96, 0.4); }

.header-meta {
  text-align: right;
  font-family: 'Fragment Mono', monospace;
  font-size: 10px; letter-spacing: 0.18em; text-transform: uppercase;
  color: var(--ink-dim); line-height: 1.6;
}
.header-meta span { color: var(--accent); }

/* ──── Info Panel ──── */
.info-panel {
  position: fixed;
  top: 96px; left: 24px;
  width: 320px; max-width: calc(100vw - 48px);
  background: var(--panel);
  backdrop-filter: blur(20px) saturate(140%);
  -webkit-backdrop-filter: blur(20px) saturate(140%);
  border: 1px solid var(--line);
  border-radius: 2px; padding: 22px 24px; z-index: 10;
}
.info-label {
  font-family: 'Fragment Mono', monospace;
  font-size: 9px; letter-spacing: 0.2em; text-transform: uppercase;
  color: var(--accent); margin-bottom: 10px;
}
.info-title {
  font-size: 24px; font-weight: 400; letter-spacing: -0.01em;
  line-height: 1.15; margin-bottom: 12px; font-style: italic;
}
.info-body { font-size: 14px; line-height: 1.55; color: var(--ink-dim); font-weight: 300; }
.info-body strong { color: var(--ink); font-weight: 500; }
.mobile-info-toggle { display: none; }

/* ──── Bottom Controls ──── */
.controls {
  position: fixed; bottom: 24px; left: 50%; transform: translateX(-50%);
  background: var(--panel);
  backdrop-filter: blur(20px) saturate(140%);
  -webkit-backdrop-filter: blur(20px) saturate(140%);
  border: 1px solid var(--line); border-radius: 2px;
  padding: 14px 22px; display: flex; align-items: center; gap: 20px;
  z-index: 10; max-width: calc(100vw - 32px);
}
.play-btn {
  background: var(--accent); color: #1a1408; border: none;
  width: 36px; height: 36px; border-radius: 50%; cursor: pointer;
  display: flex; align-items: center; justify-content: center;
  transition: all 0.2s; flex-shrink: 0;
}
.play-btn:hover { background: #ffd47a; transform: scale(1.05); }
.play-btn svg { width: 14px; height: 14px; }

.speed-group { display: flex; align-items: center; gap: 12px; }
.speed-label {
  font-family: 'Fragment Mono', monospace; font-size: 9px;
  letter-spacing: 0.18em; text-transform: uppercase; color: var(--ink-dim);
}
.speed-slider {
  -webkit-appearance: none; appearance: none;
  width: 130px; height: 24px;
  background: linear-gradient(rgba(232, 236, 244, 0.15), rgba(232, 236, 244, 0.15)) center / 100% 2px no-repeat;
  outline: none; border-radius: 0;
}
.speed-slider::-webkit-slider-thumb {
  -webkit-appearance: none; appearance: none;
  width: 12px; height: 12px; border-radius: 50%; background: var(--accent);
  cursor: pointer; border: 2px solid var(--bg); box-shadow: 0 0 0 1px var(--accent);
}
.speed-slider::-moz-range-thumb {
  width: 12px; height: 12px; border-radius: 50%; background: var(--accent);
  cursor: pointer; border: 2px solid var(--bg);
}
.speed-value {
  font-family: 'Fragment Mono', monospace; font-size: 12px;
  color: var(--ink); min-width: 46px;
}
.divider { width: 1px; height: 24px; background: var(--line); }

.toggle-group { display: flex; gap: 8px; flex-wrap: wrap; }
.toggle-btn {
  background: transparent; border: 1px solid var(--line); color: var(--ink-dim);
  padding: 7px 12px; font-family: 'Fragment Mono', monospace;
  font-size: 9px; letter-spacing: 0.15em; text-transform: uppercase;
  border-radius: 2px; cursor: pointer; transition: all 0.2s; min-height: 32px;
}
.toggle-btn:hover { color: var(--ink); border-color: rgba(232,236,244,0.2); }
.toggle-btn.active {
  color: var(--accent); border-color: rgba(244, 197, 96, 0.4);
  background: rgba(244, 197, 96, 0.05);
}

/* ──── Hint ──── */
.hint {
  position: fixed; bottom: 24px; left: 24px;
  font-family: 'Fragment Mono', monospace; font-size: 9px;
  letter-spacing: 0.18em; text-transform: uppercase; color: var(--ink-faint);
  z-index: 10; line-height: 1.8;
}
.hint .key {
  display: inline-block; padding: 2px 6px; border: 1px solid var(--line);
  border-radius: 2px; margin: 0 4px; color: var(--ink-dim);
}

/* ──── 3D labels ──── */
.label-3d {
  position: absolute; font-family: 'Fragment Mono', monospace;
  font-size: 10px; letter-spacing: 0.2em; text-transform: uppercase;
  color: var(--ink); pointer-events: none; transform: translate(-50%, -50%);
  padding: 3px 7px; background: rgba(0,0,0,0.4); border: 1px solid var(--line);
  border-radius: 2px; white-space: nowrap; z-index: 5;
  backdrop-filter: blur(8px); -webkit-backdrop-filter: blur(8px);
  transition: opacity 0.3s, color 0.2s, border-color 0.2s;
}

/* ──── Loading ──── */
.loader {
  position: fixed; inset: 0; background: var(--bg);
  display: flex; align-items: center; justify-content: center;
  z-index: 100; transition: opacity 0.8s;
}
.loader.hidden {
  opacity: 0; pointer-events: none; visibility: hidden;
  transition: opacity 0.8s, visibility 0s 0.8s;
}
.loader-text {
  font-family: 'Fragment Mono', monospace; font-size: 10px;
  letter-spacing: 0.3em; text-transform: uppercase; color: var(--accent);
  animation: pulse 1.4s ease-in-out infinite;
}
@keyframes pulse { 0%, 100% { opacity: 0.4; } 50% { opacity: 1; } }

/* ──── Scene switcher (SPACE.buildNav) ──── */
.scene-nav {
  position: fixed; top: 20px; left: 50%; transform: translateX(-50%);
  z-index: 30; font-family: 'Fragment Mono', monospace;
}
.scene-nav-btn {
  background: var(--panel); backdrop-filter: blur(20px); -webkit-backdrop-filter: blur(20px);
  border: 1px solid var(--line); color: var(--ink-dim); border-radius: 2px;
  padding: 7px 14px; font-size: 9px; letter-spacing: 0.2em; text-transform: uppercase;
  cursor: pointer; transition: all 0.2s; white-space: nowrap; min-height: 32px;
}
.scene-nav-btn:hover, .scene-nav.open .scene-nav-btn { color: var(--accent); border-color: rgba(244,197,96,0.4); }
.scene-menu {
  position: absolute; top: 40px; left: 50%; transform: translateX(-50%);
  min-width: 190px; background: var(--panel-bright);
  backdrop-filter: blur(20px); -webkit-backdrop-filter: blur(20px);
  border: 1px solid var(--line); border-radius: 2px; padding: 6px;
  display: none; flex-direction: column; gap: 2px;
}
.scene-menu[hidden] { display: none; }
.scene-nav.open .scene-menu { display: flex; }
.scene-menu a {
  text-decoration: none; color: var(--ink-dim);
  font-size: 11px; letter-spacing: 0.12em; text-transform: uppercase;
  padding: 9px 12px; border-radius: 2px; display: flex; align-items: center; gap: 10px;
  transition: all 0.18s;
}
.scene-menu a:hover { color: var(--ink); background: rgba(255,255,255,0.04); }
.scene-menu a.current { color: var(--accent); }
.scene-menu a .dot { width: 6px; height: 6px; border-radius: 50%; background: currentColor; opacity: 0.5; }
.scene-menu a.current .dot { opacity: 1; }
@media (max-width: 820px) {
  .scene-nav { top: 12px; }
  .scene-nav-btn { padding: 6px 10px; font-size: 8px; }

  /* Keep the scene visible on phones. Educational copy becomes a small
     title drawer and is available on demand instead of covering the model. */
  .info-panel.mobile-info-panel {
    padding: 12px 64px 12px 16px;
    overflow: auto;
    transition: max-height 0.25s ease, padding 0.25s ease;
  }
  .info-panel.mobile-info-panel:not(.is-expanded) {
    max-height: 66px !important;
    overflow: hidden;
  }
  .info-panel.mobile-info-panel:not(.is-expanded) > :not(.info-label):not(.info-title):not(.mobile-info-toggle) {
    display: none !important;
  }
  .info-panel.mobile-info-panel > .info-label {
    margin-bottom: 4px;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
  }
  .info-panel.mobile-info-panel > .info-title {
    margin-bottom: 0;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
  }
  .info-panel.mobile-info-panel.is-expanded > .info-title {
    margin-bottom: 12px;
    white-space: normal;
  }
  .mobile-info-toggle {
    display: inline-flex;
    position: absolute;
    top: 50%;
    right: 12px;
    transform: translateY(-50%);
    align-items: center;
    justify-content: center;
    min-width: 42px;
    min-height: 32px;
    padding: 6px 8px;
    border: 1px solid rgba(244, 197, 96, 0.28);
    border-radius: 2px;
    background: rgba(244, 197, 96, 0.06);
    color: var(--accent);
    font-family: 'Fragment Mono', monospace;
    font-size: 8px;
    letter-spacing: 0.12em;
    text-transform: uppercase;
    cursor: pointer;
  }
  .info-panel.mobile-info-panel.is-expanded .mobile-info-toggle {
    top: 12px;
    transform: none;
  }
}

@media (max-height: 520px) and (orientation: landscape) {
  .header { padding: 12px 16px; }
  .title { font-size: 16px; }
  .subtitle, .header-meta, .hint, .divider, .speed-label { display: none; }
  .info-panel {
    top: 64px !important;
    bottom: auto !important;
    max-height: calc(100vh - 140px) !important;
    overflow: auto;
    padding: 14px 16px;
  }
  .info-title { font-size: 19px; }
  .info-body { font-size: 12px; }
  .controls {
    bottom: 8px;
    padding: 7px 10px;
    gap: 8px;
    flex-wrap: nowrap;
    max-width: calc(100vw - 24px);
  }
  .speed-slider { width: 80px; }
  .toggle-group { gap: 4px; flex-wrap: nowrap; }
  .toggle-btn { padding: 5px 7px; font-size: 7px; }
  .scene-nav { top: 8px; }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    scroll-behavior: auto !important;
    transition-duration: 0.01ms !important;
  }
}