:root {
      --bg-deep: #030712;
      --bg-panel: linear-gradient(
        168deg,
        rgba(14, 28, 56, 0.96) 0%,
        rgba(8, 20, 46, 0.92) 45%,
        rgba(5, 14, 34, 0.94) 100%
      );
      --border: rgba(110, 205, 255, 0.35);
      --border-dim: rgba(70, 160, 220, 0.14);
      --accent: #5ae8ff;
      --accent-dim: rgba(90, 232, 255, 0.42);
      --accent-hot: #b8f0ff;
      --text: #eef8ff;
      --text-muted: rgba(185, 218, 248, 0.74);
      --modal-glass: linear-gradient(
        155deg,
        rgba(18, 34, 68, 0.97) 0%,
        rgba(8, 18, 44, 0.96) 48%,
        rgba(4, 12, 30, 0.98) 100%
      );
      --modal-line: rgba(120, 200, 255, 0.26);
      --modal-kicker: rgba(165, 218, 255, 0.58);
      --sidebar-open-w: clamp(240px, 26vw, 308px);
      --glass-inset: inset 0 1px 0 rgba(255, 255, 255, 0.08);
      --shadow-panel: 6px 0 36px rgba(0, 6, 24, 0.58), inset -1px 0 0 rgba(120, 200, 255, 0.12);
    }

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

    html {
      height: 100%;
    }

    body {
      font-family: "DM Sans", "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
      background:
        radial-gradient(ellipse 100% 70% at 50% -15%, rgba(45, 130, 190, 0.14), transparent 52%),
        radial-gradient(ellipse 55% 50% at 100% 40%, rgba(25, 90, 160, 0.09), transparent 48%),
        radial-gradient(ellipse 70% 55% at 0% 85%, rgba(20, 70, 140, 0.07), transparent 50%),
        var(--bg-deep);
      color: var(--text);
      height: 100%;
      min-height: 0;
      overflow: hidden;
      display: flex;
      flex-direction: column;
    }

    /** 侧栏 + 画布同行排列；全屏时整块进入全屏以保留控制面板 */
    .app-shell {
      flex: 1;
      display: flex;
      align-items: stretch;
      min-height: 0;
      min-width: 0;
      width: 100%;
      background: inherit;
    }

    .app-shell:fullscreen,
    .app-shell:-webkit-full-screen {
      background:
        radial-gradient(ellipse 100% 70% at 50% -15%, rgba(45, 130, 190, 0.14), transparent 52%),
        radial-gradient(ellipse 55% 50% at 100% 40%, rgba(25, 90, 160, 0.09), transparent 48%),
        radial-gradient(ellipse 70% 55% at 0% 85%, rgba(20, 70, 140, 0.07), transparent 50%),
        var(--bg-deep);
    }

    .sidebar {
      width: var(--sidebar-open-w);
      min-width: 0;
      flex-shrink: 0;
      overflow: hidden;
      background: var(--bg-panel);
      border-right: 1px solid var(--border-dim);
      box-shadow: var(--shadow-panel);
      backdrop-filter: blur(18px) saturate(1.25);
      -webkit-backdrop-filter: blur(18px) saturate(1.25);
      display: flex;
      flex-direction: column;
      z-index: 10;
      position: relative;
      transition: width 0.34s cubic-bezier(0.22, 1, 0.36, 1), border-color 0.32s ease;
    }

    .sidebar::before {
      content: "";
      position: absolute;
      inset: 0 0 0 0;
      background: linear-gradient(180deg, rgba(255, 255, 255, 0.06) 0%, transparent 28%);
      pointer-events: none;
      z-index: 0;
    }

    .sidebar::after {
      content: "";
      position: absolute;
      top: 0;
      bottom: 0;
      right: 0;
      width: 1px;
      background: linear-gradient(
        180deg,
        transparent,
        rgba(120, 210, 255, 0.45) 35%,
        rgba(120, 210, 255, 0.45) 65%,
        transparent
      );
      pointer-events: none;
      opacity: 0.65;
      z-index: 1;
    }

    .sidebar.collapsed {
      width: 0;
      border-right-color: transparent;
      pointer-events: none;
    }

    .sidebar-inner {
      flex: 1;
      display: flex;
      flex-direction: column;
      overflow-y: auto;
      overflow-x: hidden;
      padding: 1.35rem 1.2rem 1.05rem;
      min-width: var(--sidebar-open-w);
      box-sizing: border-box;
      position: relative;
      z-index: 2;
      scrollbar-width: thin;
      scrollbar-color: rgba(100, 190, 255, 0.35) transparent;
    }

    /* —— 版权（与「热力环流/地球自转」控制面板一致）—— */
    .copyright-entry {
      margin-top: auto;
      padding-top: 12px;
      margin-bottom: 0;
      border-top: 1px solid rgba(45, 67, 127, 0.35);
    }

    .copyright-text-btn {
      display: block;
      width: 100%;
      padding: 10px 12px;
      font-size: 13px;
      font-family: inherit;
      color: #9fb4e8;
      background: transparent;
      border: 1px solid rgba(45, 67, 127, 0.55);
      border-radius: 8px;
      cursor: pointer;
      text-align: center;
      transition: background 0.2s, border-color 0.2s, color 0.2s;
    }

    .copyright-text-btn:hover {
      background: rgba(16, 34, 74, 0.45);
      border-color: #35509a;
      color: #d4e6ff;
    }

    .copyright-modal {
      max-width: 440px;
    }

    .copyright-modal .modal-title {
      text-align: center;
    }

    .copyright-modal .modal-actions {
      justify-content: center;
    }

    .copyright-qr-grid {
      display: flex;
      flex-wrap: wrap;
      justify-content: center;
      align-items: flex-start;
      gap: 14px 16px;
      margin-bottom: 14px;
    }

    .copyright-qr-item {
      margin: 0;
      flex: 1 1 150px;
      max-width: 200px;
      min-width: 0;
      text-align: center;
    }

    .copyright-qr-caption {
      margin: 8px 0 0;
      font-size: 12px;
      line-height: 1.35;
      color: #9fb4e8;
    }

    .copyright-qr-image {
      display: block;
      width: 100%;
      max-width: 200px;
      height: auto;
      margin: 0 auto;
      border-radius: 8px;
      border: 1px solid rgba(45, 67, 127, 0.5);
    }

    .copyright-note {
      margin: 0;
      font-size: 13px;
      line-height: 1.55;
      color: #c8d6ff;
      text-align: center;
    }

    .modal-overlay {
      position: fixed;
      inset: 0;
      z-index: 20000;
      display: flex;
      align-items: center;
      justify-content: center;
      padding: 16px;
      background: rgba(0, 0, 0, 0.5);
      box-sizing: border-box;
    }

    .modal-overlay[hidden] {
      display: none !important;
    }

    .modal-dialog {
      width: 100%;
      max-width: 380px;
      padding: 18px 16px;
      border-radius: 12px;
      background: linear-gradient(180deg, #0a1428 0%, #050a14 100%);
      border: 1px solid #2d437f;
      box-shadow: 0 12px 40px rgba(0, 0, 0, 0.55);
      color: #e0e9ff;
    }

    .modal-title {
      margin: 0 0 14px;
      font-size: 17px;
      font-weight: 600;
      color: #b8d4ff;
    }

    .modal-actions {
      display: flex;
      gap: 10px;
      margin-top: 18px;
      justify-content: flex-end;
    }

    .modal-btn {
      padding: 8px 18px;
      font-size: 14px;
      border-radius: 8px;
      cursor: pointer;
      border: 1px solid #35509a;
      background: #10214b;
      color: #eff3ff;
      font-family: inherit;
    }

    .modal-btn:hover {
      background: #18306c;
    }

    .modal-btn-primary {
      border-color: #4a6caf;
      background: #1a3a7a;
    }

    .sidebar-inner::-webkit-scrollbar {
      width: 5px;
    }

    .sidebar-inner::-webkit-scrollbar-thumb {
      background: linear-gradient(180deg, rgba(100, 200, 255, 0.45), rgba(60, 140, 200, 0.25));
      border-radius: 8px;
    }

    .sidebar.collapsed .sidebar-inner {
      min-width: 0;
      opacity: 0;
      transition: opacity 0.15s ease;
    }

    .sidebar h1 {
      font-size: 1.18rem;
      font-weight: 600;
      letter-spacing: 0.08em;
      margin-bottom: 1.05rem;
      background: linear-gradient(115deg, var(--accent-hot) 0%, var(--accent) 48%, rgba(130, 210, 255, 0.95) 100%);
      -webkit-background-clip: text;
      background-clip: text;
      color: transparent;
      text-shadow: none;
      filter: drop-shadow(0 0 20px rgba(90, 232, 255, 0.35));
    }

    .control-group {
      margin-bottom: 1.08rem;
      padding: 0.72rem 0.72rem 0.82rem;
      border-radius: 12px;
      background: linear-gradient(145deg, rgba(8, 26, 52, 0.42) 0%, rgba(4, 14, 34, 0.28) 100%);
      border: 1px solid var(--border-dim);
      box-shadow: var(--glass-inset), 0 8px 28px rgba(0, 10, 35, 0.22);
    }

    .control-group > label {
      display: block;
      font-size: 0.68rem;
      color: rgba(170, 210, 245, 0.88);
      margin-bottom: 0.42rem;
      text-transform: uppercase;
      letter-spacing: 0.11em;
      font-weight: 600;
    }

    .control-group > label::before {
      content: "";
      display: inline-block;
      width: 4px;
      height: 4px;
      margin-right: 0.45rem;
      vertical-align: middle;
      border-radius: 1px;
      background: var(--accent);
      box-shadow: 0 0 10px var(--accent-dim);
    }

    .speed-row {
      display: flex;
      align-items: center;
      gap: 0.6rem;
    }

    .speed-row input[type="range"] {
      flex: 1;
      accent-color: var(--accent);
      height: 5px;
      border-radius: 999px;
      background: linear-gradient(90deg, rgba(30, 70, 110, 0.6), rgba(15, 45, 85, 0.45));
      outline: none;
    }

    .speed-row input[type="range"]::-webkit-slider-thumb {
      appearance: none;
      width: 15px;
      height: 15px;
      border-radius: 50%;
      background: radial-gradient(circle at 30% 28%, #fff 0%, var(--accent) 42%, #2088b8 100%);
      box-shadow: 0 0 12px var(--accent-dim), 0 2px 6px rgba(0, 8, 24, 0.45);
      cursor: pointer;
    }

    .speed-row input[type="range"]::-moz-range-thumb {
      width: 15px;
      height: 15px;
      border: none;
      border-radius: 50%;
      background: radial-gradient(circle at 30% 28%, #fff 0%, var(--accent) 42%, #2088b8 100%);
      box-shadow: 0 0 12px var(--accent-dim), 0 2px 6px rgba(0, 8, 24, 0.45);
      cursor: pointer;
    }

    .speed-row input[type="range"]::-moz-range-track {
      height: 5px;
      border-radius: 999px;
      background: linear-gradient(90deg, rgba(30, 70, 110, 0.6), rgba(15, 45, 85, 0.45));
    }

    .speed-val {
      font-family: "JetBrains Mono", ui-monospace, monospace;
      font-variant-numeric: tabular-nums;
      font-size: 0.82rem;
      font-weight: 500;
      color: var(--accent);
      min-width: 3.2rem;
      text-align: right;
      text-shadow: 0 0 18px var(--accent-dim);
    }

    .btn-play-pause {
      flex-shrink: 0;
      width: 40px;
      height: 40px;
      padding: 0;
      display: flex;
      align-items: center;
      justify-content: center;
      border-radius: 10px;
      border: 1px solid rgba(120, 215, 255, 0.42);
      background: linear-gradient(
        155deg,
        rgba(55, 155, 175, 0.58) 0%,
        rgba(28, 92, 125, 0.72) 50%,
        rgba(18, 62, 105, 0.82) 100%
      );
      color: rgba(240, 252, 255, 0.96);
      cursor: pointer;
      box-shadow: var(--glass-inset), 0 4px 16px rgba(0, 12, 40, 0.28);
      transition: border-color 0.2s ease, box-shadow 0.22s ease, transform 0.18s ease;
    }

    .btn-play-pause:hover {
      border-color: rgba(140, 230, 255, 0.58);
      box-shadow: var(--glass-inset), 0 0 20px var(--accent-dim);
      transform: translateY(-1px);
    }

    .btn-play-pause:active {
      transform: translateY(0);
    }

    .btn-play-pause .bpp-icon {
      width: 20px;
      height: 20px;
      display: block;
      pointer-events: none;
    }

    .btn-play-pause .bpp-play {
      display: none;
    }

    .btn-play-pause.is-paused .bpp-pause {
      display: none;
    }

    .btn-play-pause.is-paused .bpp-play {
      display: block;
    }

    .btn-play-pause:focus-visible {
      outline: 2px solid var(--accent);
      outline-offset: 2px;
    }

    .btn-row {
      display: flex;
      gap: 0.52rem;
      flex-wrap: wrap;
    }

    button.btn {
      background: linear-gradient(
        155deg,
        rgba(48, 105, 155, 0.58) 0%,
        rgba(22, 58, 105, 0.62) 48%,
        rgba(14, 42, 82, 0.72) 100%
      );
      border: 1px solid rgba(110, 200, 255, 0.32);
      color: var(--text);
      padding: 0.48rem 0.88rem;
      border-radius: 9px;
      cursor: pointer;
      font-size: 0.82rem;
      font-weight: 500;
      letter-spacing: 0.04em;
      box-shadow:
        var(--glass-inset),
        0 6px 18px rgba(0, 12, 40, 0.28);
      transition:
        border-color 0.22s ease,
        box-shadow 0.22s ease,
        transform 0.18s ease,
        background 0.22s ease;
    }

    button.btn:hover {
      border-color: rgba(130, 225, 255, 0.55);
      box-shadow:
        var(--glass-inset),
        0 0 22px var(--accent-dim),
        0 8px 26px rgba(0, 18, 48, 0.38);
      transform: translateY(-1px);
    }

    button.btn:active {
      transform: translateY(0);
    }

    button.btn.primary {
      background: linear-gradient(
        155deg,
        rgba(55, 155, 175, 0.62) 0%,
        rgba(28, 92, 125, 0.72) 50%,
        rgba(18, 62, 105, 0.82) 100%
      );
      border-color: rgba(120, 215, 255, 0.42);
    }

    button.btn.active-planet-common {
      border-color: var(--accent);
      color: var(--accent-hot);
      box-shadow:
        var(--glass-inset),
        0 0 18px var(--accent-dim),
        inset 0 0 20px rgba(90, 232, 255, 0.12);
    }

    .planet-common-btns {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 0.46rem;
    }

    .planet-common-btns .btn-span-2 {
      grid-column: 1 / -1;
    }

    .checks {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 0.48rem 0.55rem;
      align-items: flex-start;
    }

    .checks label {
      font-size: 0.76rem;
      display: flex;
      align-items: center;
      gap: 0.42rem;
      cursor: pointer;
      color: rgba(195, 225, 248, 0.88);
      padding: 0.38rem 0.48rem;
      border-radius: 8px;
      background: rgba(4, 18, 42, 0.35);
      border: 1px solid rgba(80, 160, 220, 0.12);
      transition: border-color 0.2s ease, background 0.2s ease;
    }

    .checks label:hover {
      border-color: rgba(110, 200, 255, 0.28);
      background: rgba(8, 28, 58, 0.42);
    }

    .checks input {
      accent-color: var(--accent);
      width: 15px;
      height: 15px;
    }

    .hint {
      font-size: 0.72rem;
      color: rgba(195, 222, 248, 0.82);
      margin-top: 0.85rem;
      padding: 0.62rem 0.72rem;
      border-radius: 10px;
      border: 1px solid rgba(100, 190, 255, 0.2);
      border-left-width: 3px;
      border-left-color: rgba(90, 232, 255, 0.65);
      background: linear-gradient(105deg, rgba(8, 36, 72, 0.55) 0%, rgba(4, 18, 42, 0.38) 100%);
      line-height: 1.52;
      box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.05);
    }

    .sidebar-footer {
      padding: 0.72rem 1.05rem;
      font-size: 0.66rem;
      color: rgba(165, 200, 235, 0.62);
      border-top: 1px solid var(--border-dim);
      background: linear-gradient(180deg, transparent, rgba(4, 14, 34, 0.55));
      transition: opacity 0.15s ease;
      letter-spacing: 0.04em;
      position: relative;
      z-index: 2;
    }

    .sidebar.collapsed .sidebar-footer {
      opacity: 0;
      pointer-events: none;
    }

    /** fixed：始终在视口内显示；收起后移到左缘避免被缩进侧栏盖住 */
    .sidebar-toggle {
      position: fixed;
      top: 50%;
      transform: translateY(-50%);
      z-index: 200;
      width: 28px;
      height: 54px;
      padding: 0;
      background: linear-gradient(90deg, rgba(12, 28, 58, 0.95), rgba(8, 20, 48, 0.88));
      border: 1px solid rgba(110, 200, 255, 0.35);
      border-radius: 0 10px 10px 0;
      cursor: pointer;
      display: flex;
      align-items: center;
      justify-content: center;
      color: var(--accent);
      font-size: 0.78rem;
      box-shadow:
        4px 0 22px rgba(0, 12, 40, 0.5),
        inset 0 1px 0 rgba(255, 255, 255, 0.08);
      transition:
        left 0.34s cubic-bezier(0.22, 1, 0.36, 1),
        border-radius 0.22s ease,
        box-shadow 0.22s ease,
        border-color 0.2s ease;
      left: calc(var(--sidebar-open-w) - 14px);
    }

    body.sidebar-collapsed .sidebar-toggle {
      left: 10px;
      border-radius: 10px;
      border-left: 1px solid rgba(110, 200, 255, 0.35);
    }

    .sidebar-toggle:hover {
      border-color: rgba(140, 225, 255, 0.55);
      color: var(--accent-hot);
      box-shadow:
        4px 0 26px rgba(90, 220, 255, 0.22),
        inset 0 1px 0 rgba(255, 255, 255, 0.12);
    }
    .viewport-wrap {
      flex: 1;
      position: relative;
      min-width: 0;
      min-height: 0;
      height: 100%;
      display: flex;
      flex-direction: column;
      align-items: stretch;
      justify-content: flex-start;
    }

    .viewport-animation-hint {
      position: absolute;
      left: 50%;
      transform: translateX(-50%);
      z-index: 14;
      max-width: min(520px, calc(100% - 9.5rem));
      margin: 0;
      padding: 0.42rem 0.95rem;
      text-align: center;
      font-size: 0.78rem;
      line-height: 1.45;
      font-weight: 500;
      letter-spacing: 0.02em;
      color: rgba(228, 246, 255, 0.94);
      text-shadow:
        0 0 14px rgba(0, 12, 36, 0.92),
        0 1px 2px rgba(0, 0, 0, 0.82);
      pointer-events: none;
      border: 1px solid rgba(110, 200, 255, 0.28);
      border-radius: 999px;
      background: linear-gradient(
        155deg,
        rgba(14, 38, 72, 0.62) 0%,
        rgba(8, 24, 52, 0.52) 100%
      );
      backdrop-filter: blur(12px) saturate(1.15);
      -webkit-backdrop-filter: blur(12px) saturate(1.15);
      box-shadow:
        0 8px 28px rgba(0, 12, 36, 0.35),
        inset 0 1px 0 rgba(255, 255, 255, 0.06);
    }

    .viewport-animation-hint--top {
      top: 0.72rem;
    }

    .viewport-animation-hint--bottom {
      bottom: 0.85rem;
      top: auto;
    }

    #canvas-container {
      flex: 1;
      width: 100%;
      min-height: 0;
      position: relative;
      touch-action: none;
      background:
        radial-gradient(ellipse 72% 58% at 50% 42%, rgba(24, 72, 120, 0.35) 0%, transparent 62%),
        radial-gradient(ellipse at center, #0c1e38 0%, #030812 58%);
      transform: translateY(-4vh);
    }

    #canvas-container::after {
      content: "";
      position: absolute;
      inset: 0;
      pointer-events: none;
      z-index: 1;
      opacity: 0.45;
      background:
        radial-gradient(ellipse at center, transparent 35%, rgba(0, 4, 14, 0.55) 100%),
        repeating-linear-gradient(
          0deg,
          transparent,
          transparent 3px,
          rgba(80, 160, 220, 0.035) 3px,
          rgba(80, 160, 220, 0.035) 4px
        );
      mix-blend-mode: soft-light;
    }

    #canvas-container canvas {
      display: block;
      position: relative;
      z-index: 0;
      touch-action: none;
    }

    .labels-layer {
      position: absolute;
      inset: 0;
      z-index: 3;
      overflow: hidden;
      pointer-events: none;
    }

    .labels-layer .body-label {
      position: absolute;
      left: 0;
      top: 0;
      transform: translate(-50%, -115%);
      padding: 4px 11px;
      border-radius: 6px;
      font-size: 11px;
      font-weight: 600;
      letter-spacing: 0.08em;
      color: #f2fcff;
      text-shadow:
        0 0 12px rgba(0, 20, 48, 0.95),
        0 1px 3px rgba(0, 0, 0, 0.85);
      background: linear-gradient(
        165deg,
        rgba(12, 38, 72, 0.82) 0%,
        rgba(6, 22, 52, 0.78) 100%
      );
      border: 1px solid rgba(130, 210, 255, 0.38);
      backdrop-filter: blur(8px);
      -webkit-backdrop-filter: blur(8px);
      box-shadow:
        0 4px 18px rgba(0, 8, 28, 0.45),
        inset 0 1px 0 rgba(255, 255, 255, 0.1);
      white-space: nowrap;
      visibility: hidden;
    }

    .labels-layer .body-label-comet {
      color: #e8f4ff;
      border-color: rgba(160, 220, 255, 0.48);
      background: linear-gradient(
        165deg,
        rgba(18, 42, 78, 0.84) 0%,
        rgba(8, 28, 58, 0.8) 100%
      );
    }

    .overlay-box {
      background: linear-gradient(
        158deg,
        rgba(10, 30, 62, 0.82) 0%,
        rgba(6, 20, 48, 0.78) 55%,
        rgba(4, 14, 38, 0.85) 100%
      );
      border: 1px solid rgba(110, 200, 255, 0.34);
      border-radius: 12px;
      padding: 0.78rem 0.95rem;
      backdrop-filter: blur(16px) saturate(1.25);
      -webkit-backdrop-filter: blur(16px) saturate(1.25);
      pointer-events: none;
      box-shadow:
        0 12px 40px rgba(0, 8, 32, 0.45),
        inset 0 1px 0 rgba(255, 255, 255, 0.08),
        inset 0 0 40px rgba(90, 200, 255, 0.04);
      position: relative;
      overflow: hidden;
    }

    .overlay-data.overlay-box {
      padding: 0.62rem 0.72rem 0.68rem;
    }

    .overlay-data.overlay-box::before {
      content: "";
      position: absolute;
      top: 0;
      left: 0;
      right: 18%;
      height: 2px;
      background: linear-gradient(90deg, rgba(90, 232, 255, 0.95), transparent);
      pointer-events: none;
    }

    .overlay-data.overlay-box::after {
      content: "";
      position: absolute;
      bottom: 6px;
      right: 8px;
      width: 36px;
      height: 36px;
      border-right: 1px solid rgba(130, 210, 255, 0.35);
      border-bottom: 1px solid rgba(130, 210, 255, 0.35);
      border-radius: 0 0 8px 0;
      pointer-events: none;
      opacity: 0.65;
    }

    .overlay-box h3 {
      font-size: 0.68rem;
      font-weight: 700;
      letter-spacing: 0.14em;
      text-transform: uppercase;
      color: rgba(185, 235, 255, 0.95);
      margin: 0;
      text-shadow: 0 0 20px rgba(90, 232, 255, 0.25);
    }

    .overlay-box p {
      font-size: 0.78rem;
      color: var(--text-muted);
      line-height: 1.5;
    }

    .overlay-data {
      position: absolute;
      bottom: 0.85rem;
      right: 1rem;
      width: fit-content;
      max-width: min(268px, calc(100% - 1.5rem));
      pointer-events: auto;
      z-index: 12;
      transition:
        padding 0.28s cubic-bezier(0.22, 1, 0.36, 1),
        box-shadow 0.28s ease;
    }

    .overlay-data.collapsed {
      padding-bottom: 0.55rem;
    }

    .overlay-data-header {
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 0.5rem;
      margin-bottom: 0.48rem;
      position: relative;
      z-index: 2;
    }

    .overlay-data.collapsed .overlay-data-header {
      margin-bottom: 0;
    }

    .overlay-data-toggle {
      flex-shrink: 0;
      width: 26px;
      height: 26px;
      padding: 0;
      display: flex;
      align-items: center;
      justify-content: center;
      border-radius: 7px;
      border: 1px solid rgba(110, 200, 255, 0.32);
      background: rgba(8, 28, 58, 0.55);
      color: rgba(200, 235, 255, 0.9);
      cursor: pointer;
      transition:
        border-color 0.2s ease,
        color 0.2s ease,
        background 0.2s ease,
        transform 0.18s ease;
    }

    .overlay-data-toggle:hover {
      border-color: rgba(140, 230, 255, 0.55);
      color: var(--accent-hot);
      background: rgba(14, 42, 78, 0.72);
    }

    .overlay-data-toggle-icon {
      display: block;
      transition: transform 0.28s cubic-bezier(0.22, 1, 0.36, 1);
    }

    .overlay-data.collapsed .overlay-data-toggle-icon {
      transform: rotate(180deg);
    }

    .overlay-data-body {
      overflow: hidden;
      max-height: 420px;
      opacity: 1;
      transition:
        max-height 0.32s cubic-bezier(0.22, 1, 0.36, 1),
        opacity 0.22s ease;
    }

    .overlay-data.collapsed .overlay-data-body {
      max-height: 0;
      opacity: 0;
      pointer-events: none;
    }

    .overlay-data dl {
      display: grid;
      grid-template-columns: max-content minmax(0, max-content);
      gap: 0.26rem 0.5rem;
      font-size: 0.7rem;
      position: relative;
      z-index: 1;
    }

    .overlay-data dt {
      color: rgba(155, 200, 235, 0.72);
      font-weight: 500;
    }

    .overlay-data dd {
      font-family: "JetBrains Mono", ui-monospace, monospace;
      font-variant-numeric: tabular-nums;
      font-size: 0.69rem;
      font-weight: 450;
      color: rgba(228, 246, 255, 0.96);
      line-height: 1.38;
      word-break: keep-all;
      white-space: nowrap;
      letter-spacing: -0.02em;
      text-shadow: 0 0 14px rgba(90, 200, 255, 0.12);
    }

    .viewport-top-actions {
      position: absolute;
      top: 0.72rem;
      right: 0.85rem;
      z-index: 18;
      display: flex;
      flex-direction: row;
      align-items: center;
      gap: 0.48rem;
      pointer-events: none;
    }

    .viewport-top-actions > * {
      pointer-events: auto;
    }

    .viewport-reset-toggle {
      flex-shrink: 0;
      width: 40px;
      height: 40px;
      padding: 0;
      display: flex;
      align-items: center;
      justify-content: center;
      border-radius: 10px;
      border: 1px solid rgba(110, 200, 255, 0.38);
      background: linear-gradient(
        155deg,
        rgba(14, 38, 72, 0.88) 0%,
        rgba(8, 24, 52, 0.85) 100%
      );
      color: rgba(235, 248, 255, 0.96);
      cursor: pointer;
      backdrop-filter: blur(14px);
      -webkit-backdrop-filter: blur(14px);
      box-shadow:
        0 8px 28px rgba(0, 12, 36, 0.42),
        inset 0 1px 0 rgba(255, 255, 255, 0.08);
      transition:
        border-color 0.22s ease,
        box-shadow 0.22s ease,
        color 0.2s ease,
        transform 0.18s ease;
    }

    .viewport-reset-toggle:hover {
      border-color: rgba(140, 230, 255, 0.58);
      color: var(--accent-hot);
      box-shadow:
        0 0 22px var(--accent-dim),
        0 10px 32px rgba(0, 14, 42, 0.38);
      transform: translateY(-1px);
    }

    .viewport-reset-toggle:active {
      transform: translateY(0);
    }

    .viewport-reset-toggle:focus-visible {
      outline: 2px solid var(--accent);
      outline-offset: 2px;
    }

    .viewport-fs-toggle {
      position: relative;
      top: auto;
      right: auto;
      z-index: 18;
      padding: 0.46rem 0.95rem;
      background: linear-gradient(
        155deg,
        rgba(14, 38, 72, 0.88) 0%,
        rgba(8, 24, 52, 0.85) 100%
      );
      border: 1px solid rgba(110, 200, 255, 0.38);
      border-radius: 10px;
      color: rgba(235, 248, 255, 0.96);
      font-size: 0.73rem;
      font-family: inherit;
      font-weight: 600;
      letter-spacing: 0.08em;
      cursor: pointer;
      backdrop-filter: blur(14px);
      -webkit-backdrop-filter: blur(14px);
      box-shadow:
        0 8px 28px rgba(0, 12, 36, 0.42),
        inset 0 1px 0 rgba(255, 255, 255, 0.08);
      transition:
        border-color 0.22s ease,
        box-shadow 0.22s ease,
        color 0.2s ease,
        transform 0.18s ease;
      pointer-events: auto;
    }

    .viewport-fs-toggle:hover {
      border-color: rgba(140, 230, 255, 0.58);
      color: var(--accent-hot);
      box-shadow:
        0 0 22px var(--accent-dim),
        0 10px 32px rgba(0, 14, 42, 0.38);
      transform: translateY(-1px);
    }

    .viewport-fs-toggle:active {
      transform: translateY(0);
    }

    .viewport-fs-toggle:focus-visible {
      outline: 2px solid var(--accent);
      outline-offset: 2px;
    }

    /* Modal — 天文档案卡片风格 */
    .modal-backdrop {
      position: fixed;
      inset: 0;
      z-index: 400;
      display: none;
      align-items: center;
      justify-content: center;
      padding: clamp(1rem, 4vw, 2rem);
      background:
        radial-gradient(ellipse 80% 60% at 50% 30%, rgba(25, 70, 120, 0.22), transparent 55%),
        rgba(2, 6, 18, 0.78);
      backdrop-filter: blur(14px) saturate(1.15);
      -webkit-backdrop-filter: blur(14px) saturate(1.15);
    }

    .modal-backdrop.visible {
      display: flex;
      animation: modalBackdropIn 0.38s ease forwards;
    }

    @keyframes modalBackdropIn {
      from { opacity: 0; }
      to { opacity: 1; }
    }

    .modal {
      font-family: "DM Sans", "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
      background: var(--modal-glass);
      border: 1px solid var(--modal-line);
      border-radius: 18px;
      max-width: min(560px, 100%);
      width: 100%;
      max-height: min(86vh, 680px);
      overflow: hidden;
      display: flex;
      flex-direction: column;
      box-shadow:
        0 0 0 1px rgba(255, 255, 255, 0.06) inset,
        0 40px 120px rgba(0, 8, 40, 0.72),
        0 0 100px rgba(62, 224, 255, 0.07);
      position: relative;
      animation: modalCardIn 0.45s cubic-bezier(0.22, 1, 0.36, 1) forwards;
    }

    .modal::before {
      content: "";
      position: absolute;
      top: 0;
      left: 0;
      right: 0;
      height: 1px;
      background: linear-gradient(
        90deg,
        transparent 0%,
        rgba(130, 210, 255, 0.45) 22%,
        rgba(255, 210, 170, 0.35) 50%,
        rgba(130, 210, 255, 0.45) 78%,
        transparent 100%
      );
      pointer-events: none;
      z-index: 2;
    }

    .modal::after {
      content: "";
      position: absolute;
      inset: 0;
      border-radius: inherit;
      pointer-events: none;
      box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.05);
      z-index: 1;
    }

    @keyframes modalCardIn {
      from {
        opacity: 0;
        transform: translateY(18px) scale(0.96);
      }
      to {
        opacity: 1;
        transform: translateY(0) scale(1);
      }
    }

    .modal-header {
      padding: 1.25rem 1.35rem 1.1rem;
      border-bottom: 1px solid rgba(120, 200, 255, 0.12);
      display: flex;
      justify-content: space-between;
      align-items: flex-start;
      gap: 1rem;
      position: relative;
      z-index: 3;
      background: linear-gradient(180deg, rgba(255, 255, 255, 0.03) 0%, transparent 100%);
    }

    .modal-title-area {
      min-width: 0;
    }

    .modal-kicker {
      display: block;
      font-size: 0.62rem;
      font-weight: 600;
      letter-spacing: 0.28em;
      text-transform: uppercase;
      color: var(--modal-kicker);
      margin-bottom: 0.45rem;
    }

    .modal-header h2 {
      font-family: "Noto Serif SC", "PingFang SC", "Microsoft YaHei", serif;
      font-size: 1.42rem;
      font-weight: 600;
      letter-spacing: 0.06em;
      color: #eaf8ff;
      text-shadow: 0 0 40px rgba(100, 200, 255, 0.25);
      line-height: 1.25;
    }

    .modal-header .en {
      font-size: 0.8rem;
      font-style: italic;
      font-weight: 400;
      letter-spacing: 0.04em;
      color: rgba(180, 215, 245, 0.72);
      margin-top: 0.35rem;
    }

    .modal-close {
      background: rgba(8, 24, 52, 0.65);
      border: 1px solid rgba(120, 200, 255, 0.22);
      color: rgba(220, 235, 255, 0.85);
      width: 38px;
      height: 38px;
      border-radius: 50%;
      cursor: pointer;
      font-size: 1.25rem;
      line-height: 1;
      flex-shrink: 0;
      display: flex;
      align-items: center;
      justify-content: center;
      transition: border-color 0.22s ease, background 0.22s ease, color 0.22s ease, transform 0.2s ease;
    }

    .modal-close:hover {
      border-color: rgba(100, 210, 255, 0.55);
      background: rgba(30, 70, 110, 0.55);
      color: var(--accent);
      transform: rotate(90deg);
    }

    .modal-body {
      padding: 1.15rem 1.35rem 1.35rem;
      overflow-y: auto;
      font-size: 0.9rem;
      line-height: 1.82;
      color: rgba(235, 245, 255, 0.94);
      letter-spacing: 0.03em;
      position: relative;
      z-index: 3;
      scrollbar-width: thin;
      scrollbar-color: rgba(100, 180, 255, 0.35) transparent;
    }

    .modal-body::-webkit-scrollbar {
      width: 6px;
    }

    .modal-body::-webkit-scrollbar-thumb {
      background: rgba(100, 180, 255, 0.28);
      border-radius: 6px;
    }

    .modal-body .modal-photo-wrap {
      margin: 0 0 1.15rem;
      padding: 0;
      border-radius: 14px;
      overflow: hidden;
      border: 1px solid rgba(120, 200, 255, 0.18);
      background:
        radial-gradient(ellipse 70% 50% at 50% 0%, rgba(40, 90, 140, 0.35), transparent 65%),
        rgba(4, 14, 36, 0.92);
      display: none;
      text-align: center;
      box-shadow:
        inset 0 1px 0 rgba(255, 255, 255, 0.06),
        0 16px 48px rgba(0, 8, 28, 0.55);
      position: relative;
    }

    .modal-body .modal-photo-wrap.is-visible {
      display: block;
      animation: modalPhotoReveal 0.55s ease 0.08s both;
    }

    @keyframes modalPhotoReveal {
      from {
        transform: translateY(8px) scale(0.985);
      }
      to {
        transform: translateY(0) scale(1);
      }
    }

    .modal-body .modal-photo-wrap img {
      width: 100%;
      max-height: min(42vh, 340px);
      height: auto;
      object-fit: contain;
      vertical-align: middle;
      display: block;
    }

    .modal-body .modal-photo-wrap::after {
      content: "";
      position: absolute;
      inset: 0;
      border-radius: inherit;
      pointer-events: none;
      box-shadow: inset 0 0 0 1px rgba(255, 255, 255, 0.06);
    }

    .modal-body .meta {
      font-size: 0.76rem;
      color: rgba(175, 210, 240, 0.82);
      margin-bottom: 1rem;
      padding: 0.65rem 0.85rem;
      border-radius: 10px;
      border: 1px solid rgba(120, 200, 255, 0.12);
      background: rgba(4, 18, 42, 0.45);
      line-height: 1.65;
    }

    .modal-body .meta .modal-param-grid {
      margin: 0;
      padding: 0;
    }

    .modal-body .meta .modal-param-row {
      display: grid;
      grid-template-columns: minmax(7rem, 38%) 1fr;
      gap: 0.28rem 0.75rem;
      align-items: baseline;
      padding: 0.4rem 0;
      border-bottom: 1px solid rgba(120, 200, 255, 0.1);
    }

    .modal-body .meta .modal-param-row:last-child {
      border-bottom: none;
      padding-bottom: 0;
    }

    .modal-body .meta .modal-param-grid dt {
      margin: 0;
      font-size: 0.71rem;
      font-weight: 600;
      letter-spacing: 0.04em;
      color: rgba(145, 205, 248, 0.92);
    }

    .modal-body .meta .modal-param-grid dd {
      margin: 0;
      font-size: 0.73rem;
      line-height: 1.58;
      color: rgba(218, 235, 255, 0.96);
    }

    .modal-body .meta .modal-param-fallback + .modal-param-fallback {
      margin-top: 0.35rem;
    }

    .modal-footer {
      padding: 0 1.35rem 1.35rem;
      position: relative;
      z-index: 3;
      flex-shrink: 0;
    }

    .btn-modal-primary {
      width: 100%;
      padding: 0.65rem 1rem;
      border-radius: 999px;
      border: 1px solid rgba(100, 200, 255, 0.38);
      background: linear-gradient(
        165deg,
        rgba(55, 130, 165, 0.65) 0%,
        rgba(28, 72, 110, 0.85) 50%,
        rgba(18, 52, 88, 0.92) 100%
      );
      color: #f0fbff;
      font-size: 0.88rem;
      font-weight: 600;
      letter-spacing: 0.12em;
      cursor: pointer;
      box-shadow:
        0 4px 24px rgba(40, 120, 180, 0.35),
        inset 0 1px 0 rgba(255, 255, 255, 0.12);
      transition: transform 0.2s ease, box-shadow 0.22s ease, border-color 0.2s ease;
    }

    .btn-modal-primary:hover {
      border-color: rgba(130, 230, 255, 0.65);
      box-shadow:
        0 6px 32px rgba(62, 200, 255, 0.28),
        inset 0 1px 0 rgba(255, 255, 255, 0.15);
      transform: translateY(-1px);
    }

    .btn-modal-primary:active {
      transform: translateY(0);
    }

    @media (prefers-reduced-motion: reduce) {
      button.btn:hover,
      .viewport-fs-toggle:hover,
      .viewport-reset-toggle:hover,
      .btn-play-pause:hover {
        transform: none;
      }
      .modal-backdrop.visible {
        animation: none;
      }
      .modal {
        animation: none;
      }
      .modal-body .modal-photo-wrap.is-visible {
        animation: none;
      }
      .modal-close:hover {
        transform: none;
      }
      .btn-modal-primary:hover {
        transform: none;
      }
    }

    .loading {
      position: absolute;
      inset: 0;
      display: flex;
      align-items: center;
      justify-content: center;
      background:
        radial-gradient(ellipse at center, rgba(20, 60, 100, 0.35), transparent 55%),
        var(--bg-deep);
      z-index: 50;
      flex-direction: column;
      gap: 1rem;
      transition: opacity 0.5s ease;
    }

    .loading.hidden {
      opacity: 0;
      pointer-events: none;
    }

    .loading span {
      font-size: 0.82rem;
      font-weight: 500;
      letter-spacing: 0.06em;
      color: rgba(185, 220, 248, 0.82);
      text-shadow: 0 0 24px rgba(90, 200, 255, 0.2);
    }

    .spinner {
      width: 44px;
      height: 44px;
      border: 2px solid rgba(110, 200, 255, 0.12);
      border-top-color: var(--accent);
      border-right-color: rgba(90, 232, 255, 0.45);
      border-radius: 50%;
      animation: spin 0.9s linear infinite;
      box-shadow: 0 0 24px rgba(90, 232, 255, 0.22);
    }

    @keyframes spin {
      to { transform: rotate(360deg); }
    }

    @media (max-width: 480px) {
      .viewport-animation-hint {
        font-size: 0.68rem;
        max-width: calc(100% - 2rem);
        padding: 0.38rem 0.72rem;
        line-height: 1.4;
      }

      .modal-body .meta .modal-param-row {
        grid-template-columns: 1fr;
        gap: 0.15rem 0;
      }
    }

    @media (max-width: 900px) {
      body {
        flex-direction: column;
      }

      .app-shell {
        flex-direction: column;
      }

      :root {
        --sidebar-open-w: 100%;
      }

      .sidebar:not(.collapsed) {
        width: 100%;
        max-height: 46vh;
      }

      .sidebar.collapsed {
        width: 0;
        max-height: 0;
      }

      .sidebar-toggle {
        left: 12px !important;
        top: auto;
        bottom: 18px;
        transform: none;
        border-radius: 8px;
        border-left: 1px solid var(--border);
      }
    }