* { box-sizing: border-box; margin: 0; padding: 0; }
    body {
      background-color: #05080f;
      color: #e2e8f0;
      font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Microsoft YaHei", sans-serif;
      display: flex;
      flex-direction: column;
      height: 100vh;
      overflow: hidden;
    }

    /* 语言切换 */
    .lang-switch {
      display: inline-flex;
      align-items: center;
      gap: 3px;
      background: rgba(15, 23, 42, 0.82);
      border: 1px solid rgba(148, 163, 184, 0.22);
      border-radius: 999px;
      padding: 3px 6px;
      backdrop-filter: blur(8px);
    }
    .lang-btn {
      background: transparent;
      border: none;
      color: #94a3b8;
      font-family: inherit;
      font-size: 0.78rem;
      font-weight: 600;
      padding: 3px 8px;
      border-radius: 999px;
      cursor: pointer;
      transition: all 0.15s;
    }
    .lang-btn:hover { color: #f8fafc; }
    .lang-btn.active {
      color: #0f172a;
      background: #38bdf8;
    }
    .lang-sep {
      color: #64748b;
      opacity: 0.4;
      font-size: 0.75rem;
    }

    header {
      padding: 10px 24px;
      background: linear-gradient(180deg, #0d1117 0%, #080c15 100%);
      border-bottom: 1px solid #1e293b;
      display: flex;
      justify-content: space-between;
      align-items: center;
      flex-shrink: 0;
    }
    header h1 {
      font-size: 1.05rem;
      font-weight: 600;
      background: linear-gradient(135deg, #38bdf8, #818cf8);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
    }
    header p { font-size: 0.75rem; color: #64748b; }

    .container {
      display: flex;
      flex: 1;
      overflow: hidden;
    }

    .canvas-container {
      flex: 1;
      position: relative;
      background: radial-gradient(ellipse at 10% 50%, #0c1220 0%, #040609 100%);
    }
    canvas { width: 100%; height: 100%; display: block; }

    /* 右侧任务面板 */
    .mission-panel {
      width: 290px;
      background: rgba(13, 17, 23, 0.97);
      border-left: 1px solid #1e293b;
      padding: 14px;
      display: flex;
      flex-direction: column;
      gap: 12px;
      overflow-y: auto;
      flex-shrink: 0;
    }
    .mission-panel::-webkit-scrollbar { width: 4px; }
    .mission-panel::-webkit-scrollbar-thumb { background: #334155; border-radius: 4px; }

    .section {
      background: #111827;
      padding: 12px;
      border-radius: 10px;
      border: 1px solid #1e293b;
    }
    .section-title {
      font-size: 0.72rem;
      font-weight: 600;
      color: #64748b;
      text-transform: uppercase;
      letter-spacing: 0.08em;
      margin-bottom: 10px;
    }

    /* 速度显示 */
    .speed-display {
      text-align: center;
      padding: 10px 0;
    }
    .speed-value {
      font-size: 2rem;
      font-weight: 700;
      background: linear-gradient(135deg, #4ade80, #38bdf8);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
    }
    .speed-unit { font-size: 0.75rem; color: #64748b; }
    .speed-sub {
      font-size: 0.78rem;
      margin-top: 4px;
    }
    .speed-gain { color: #4ade80; }
    .speed-loss { color: #f87171; }

    /* 飞行日志 */
    .log-item {
      display: flex;
      align-items: center;
      gap: 10px;
      padding: 7px 0;
      border-bottom: 1px solid #1e293b;
      font-size: 0.78rem;
    }
    .log-item:last-child { border-bottom: none; }
    .log-dot {
      width: 10px;
      height: 10px;
      border-radius: 50%;
      flex-shrink: 0;
      border: 2px solid;
      transition: all 0.3s;
    }
    .log-dot.visited {
      box-shadow: 0 0 6px currentColor;
    }
    .log-name { flex: 1; color: #94a3b8; }
    .log-name.visited { color: #e2e8f0; font-weight: 500; }
    .log-speed { font-family: monospace; font-size: 0.72rem; color: #4ade80; }

    /* 控制按钮 */
    .ctrl-row {
      display: flex;
      gap: 8px;
    }
    .ctrl-btn {
      flex: 1;
      padding: 8px;
      background: #1e293b;
      border: 1px solid #334155;
      color: #e2e8f0;
      border-radius: 8px;
      font-size: 0.78rem;
      font-family: inherit;
      cursor: pointer;
      transition: all 0.15s;
    }
    .ctrl-btn:hover { background: #334155; }
    .ctrl-label {
      display: flex;
      justify-content: space-between;
      font-size: 0.73rem;
      color: #94a3b8;
      margin-bottom: 3px;
    }
    .ctrl-label .val { color: #38bdf8; font-family: monospace; }
    input[type="range"] {
      width: 100%;
      accent-color: #3b82f6;
      cursor: pointer;
      margin-bottom: 8px;
    }

    /* 画布上的浮层 */
    .hud-speed {
      position: absolute;
      top: 14px;
      left: 14px;
      background: rgba(5, 8, 15, 0.85);
      border: 1px solid rgba(56, 189, 248, 0.2);
      padding: 10px 14px;
      border-radius: 10px;
      font-family: monospace;
      font-size: 0.75rem;
      color: #cbd5e1;
      pointer-events: none;
    }
    .hud-row { display: flex; justify-content: space-between; gap: 14px; margin-bottom: 3px; }
    .hud-row:last-child { margin-bottom: 0; }

    .hud-legend {
      position: absolute;
      bottom: 14px;
      left: 14px;
      background: rgba(5, 8, 15, 0.85);
      border: 1px solid rgba(56, 189, 248, 0.15);
      padding: 8px 12px;
      border-radius: 8px;
      font-size: 0.7rem;
      color: #94a3b8;
      pointer-events: none;
    }
    .legend-row { display: flex; align-items: center; gap: 6px; margin-bottom: 3px; }
    .legend-row:last-child { margin-bottom: 0; }
    .leg-line { width: 20px; height: 2px; border-radius: 1px; flex-shrink: 0; }

    /* 任务状态 */
    .mission-status {
      text-align: center;
      font-size: 0.82rem;
      color: #fbbf24;
      padding: 6px;
      background: rgba(251, 191, 36, 0.08);
      border-radius: 6px;
      min-height: 32px;
      display: flex;
      align-items: center;
      justify-content: center;
    }

/* ── Back-to-home button (shared across all pages) ── */
#homeBtn {
  position: fixed;
  top: 14px;
  left: 14px;
  z-index: 100;
  display: inline-flex;
  align-items: center;
  gap: 7px;
  height: 38px;
  padding: 0 18px 0 14px;
  background: rgba(15, 23, 42, 0.82);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid rgba(148, 163, 184, 0.22);
  border-radius: 19px;
  color: #e2e8f0;
  font-size: 0.85rem;
  font-weight: 600;
  line-height: 1;
  text-decoration: none;
  white-space: nowrap;
  cursor: pointer;
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.35);
  transition: background 0.25s ease, border-color 0.25s ease, transform 0.25s ease;
}
#homeBtn:hover {
  background: rgba(30, 41, 59, 0.95);
  border-color: rgba(148, 163, 184, 0.45);
  color: #ffffff;
  transform: translateY(-1px);
}
#homeBtn:active { transform: translateY(0); }

/* ── make room for the fixed #homeBtn ── */
header { padding-left: 132px; }
@media (max-width: 720px) { header { padding-left: 24px; } }