:root {
    --bg-primary: #0b0f17;
    --bg-secondary: #131a26;
    --bg-tertiary: #1b2536;
    --bg-card: #111722;
    --border-color: #243247;
    --text-primary: #f0f4fc;
    --text-secondary: #9cb1d1;
    --text-muted: #5e7394;
    --accent-blue: #3b82f6;
    --accent-cyan: #06b6d4;
    --accent-green: #10b981;
    --accent-amber: #f59e0b;
    --accent-rose: #f43f5e;
  }
  * { box-sizing: border-box; margin: 0; padding: 0; }
  body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.5;
    padding: 20px;
  }
  .container { max-width: 1440px; margin: 0 auto; }
  header {
    background: linear-gradient(135deg, #101622 0%, #1a2333 100%);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 20px 28px;
    margin-bottom: 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 16px;
  }
  h1 { font-size: 1.5rem; font-weight: 700; color: #fff; display: flex; align-items: center; gap: 12px; }
  .subtitle { color: var(--text-secondary); font-size: 0.85rem; margin-top: 4px; }
  .status-badge {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 6px 14px;
    border-radius: 9999px;
    font-weight: 700;
    font-size: 0.8rem;
    letter-spacing: 0.05em;
    background: rgba(16, 185, 129, 0.15);
    color: var(--accent-green);
    border: 1px solid rgba(16, 185, 129, 0.4);
  }
  .epistemic-tag {
    display: inline-block;
    padding: 2px 8px;
    border-radius: 4px;
    font-size: 0.7rem;
    font-weight: 700;
    letter-spacing: 0.03em;
    text-transform: uppercase;
  }
  .tag-geo { background: rgba(37, 99, 235, 0.2); color: #60a5fa; border: 1px solid rgba(37, 99, 235, 0.4); }
  .tag-hypo { background: rgba(139, 92, 246, 0.2); color: #c084fc; border: 1px solid rgba(139, 92, 246, 0.4); }
  .tag-approx { background: rgba(245, 158, 11, 0.2); color: #fbbf24; border: 1px solid rgba(245, 158, 11, 0.4); }

  /* Grid layout */
  .grid-2 { display: grid; grid-template-columns: 2.1fr 1fr; gap: 20px; margin-bottom: 20px; }
  .grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; margin-bottom: 20px; }
  @media (max-width: 1080px) {
    .grid-2, .grid-3 { grid-template-columns: 1fr; }
  }

  /* Cards */
  .card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 10px;
    padding: 18px;
    position: relative;
  }
  .card-title {
    font-size: 0.95rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 14px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 8px;
  }

  /* 3D Viewport */
  .viewport-container {
    position: relative;
    background: #06090e;
    border-radius: 8px;
    overflow: hidden;
    height: 520px;
    border: 1px solid var(--border-color);
  }
  #gl-canvas {
    width: 100%;
    height: 100%;
    display: block;
  }
  #static-img-view {
    width: 100%;
    height: 100%;
    object-fit: contain;
    display: none;
    background: #06090e;
  }

  /* Viewport Overlay Controls */
  .viewport-overlay {
    position: absolute;
    top: 12px;
    left: 12px;
    background: rgba(11, 15, 23, 0.82);
    backdrop-filter: blur(8px);
    border: 1px solid var(--border-color);
    border-radius: 6px;
    padding: 8px 12px;
    font-size: 0.75rem;
    color: var(--text-secondary);
    display: flex;
    flex-direction: column;
    gap: 4px;
    pointer-events: none;
  }
  .viewport-cam-bar {
    position: absolute;
    bottom: 12px;
    right: 12px;
    display: flex;
    gap: 6px;
    background: rgba(11, 15, 23, 0.85);
    backdrop-filter: blur(8px);
    border: 1px solid var(--border-color);
    border-radius: 6px;
    padding: 4px 6px;
  }
  .cam-btn {
    background: var(--bg-tertiary);
    color: var(--text-secondary);
    border: 1px solid var(--border-color);
    padding: 4px 8px;
    border-radius: 4px;
    cursor: pointer;
    font-size: 0.7rem;
    font-weight: 600;
  }
  .cam-btn:hover { background: var(--accent-blue); color: #fff; }

  /* Legend */
  .flow-legend {
    position: absolute;
    bottom: 12px;
    left: 12px;
    background: rgba(11, 15, 23, 0.85);
    backdrop-filter: blur(8px);
    border: 1px solid var(--border-color);
    border-radius: 6px;
    padding: 6px 12px;
    font-size: 0.72rem;
    color: var(--text-secondary);
  }
  .legend-bar {
    height: 8px;
    width: 130px;
    background: linear-gradient(to right, #1e50c8, #06b6d4, #10b981, #f59e0b, #f43f5e);
    border-radius: 4px;
    margin: 4px 0 2px 0;
  }
  .legend-labels { display: flex; justify-content: space-between; font-size: 0.65rem; color: var(--text-muted); }

  /* View tabs */
  .view-tabs {
    display: flex;
    gap: 6px;
    margin-top: 12px;
    flex-wrap: wrap;
  }
  .view-btn {
    background: var(--bg-secondary);
    color: var(--text-secondary);
    border: 1px solid var(--border-color);
    padding: 6px 12px;
    border-radius: 6px;
    cursor: pointer;
    font-size: 0.8rem;
    font-weight: 600;
    transition: all 0.15s ease;
  }
  .view-btn:hover { background: var(--bg-tertiary); color: #fff; }
  .view-btn.active {
    background: var(--accent-blue);
    color: #fff;
    border-color: var(--accent-blue);
  }
  .btn-preset {
    flex: 1;
    background: var(--bg-secondary);
    color: var(--text-secondary);
    border: 1px solid var(--border-color);
    padding: 5px 6px;
    border-radius: 4px;
    font-size: 0.72rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.15s ease;
  }
  .btn-preset:hover {
    background: var(--bg-tertiary);
    color: #fff;
  }
  .btn-preset.active {
    background: var(--accent-blue);
    color: #fff;
    border-color: var(--accent-blue);
  }

  /* Sliders & Controls */
  .control-group {
    margin-bottom: 14px;
  }
  .control-header {
    display: flex;
    justify-content: space-between;
    font-size: 0.8rem;
    color: var(--text-secondary);
    margin-bottom: 4px;
  }
  .control-header strong { color: var(--text-primary); font-family: ui-monospace, monospace; }
  input[type="range"] {
    width: 100%;
    height: 6px;
    background: var(--bg-tertiary);
    border-radius: 4px;
    outline: none;
    -webkit-appearance: none;
  }
  input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 16px;
    height: 16px;
    border-radius: 50%;
    background: var(--accent-cyan);
    cursor: pointer;
    border: 2px solid #fff;
  }

  /* Toggle Buttons */
  .btn-toggle-group {
    display: flex;
    gap: 4px;
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 6px;
    padding: 2px;
  }
  .btn-toggle {
    flex: 1;
    background: transparent;
    border: none;
    color: var(--text-muted);
    padding: 6px;
    font-size: 0.75rem;
    font-weight: 600;
    border-radius: 4px;
    cursor: pointer;
  }
  .btn-toggle.active {
    background: var(--accent-blue);
    color: #fff;
  }

  /* Metric rows */
  .metric-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 6px 0;
    border-bottom: 1px solid rgba(36, 50, 71, 0.4);
    font-size: 0.85rem;
  }
  .metric-row:last-child { border-bottom: none; }
  .metric-label { color: var(--text-secondary); }
  .metric-val { font-weight: 600; font-family: ui-monospace, SFMono-Regular, Menlo, monospace; }

  /* Gate pills */
  .gate-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 6px 10px;
    background: var(--bg-secondary);
    border-radius: 6px;
    margin-bottom: 6px;
    font-size: 0.8rem;
  }
  .gate-pass { color: var(--accent-green); font-weight: 700; }

  /* Artifact links table */
  .artifact-table { width: 100%; border-collapse: collapse; font-size: 0.8rem; }
  .artifact-table th, .artifact-table td {
    text-align: left;
    padding: 8px 10px;
    border-bottom: 1px solid var(--border-color);
  }
  .artifact-table th { color: var(--text-muted); font-size: 0.7rem; text-transform: uppercase; }
  .artifact-table a { color: var(--accent-cyan); text-decoration: none; font-weight: 600; }
  .artifact-table a:hover { text-decoration: underline; }

  .notice-banner {
    background: rgba(245, 158, 11, 0.1);
    border: 1px solid rgba(245, 158, 11, 0.3);
    border-radius: 8px;
    padding: 10px 14px;
    font-size: 0.75rem;
    color: #fde68a;
    margin-bottom: 20px;
    display: flex;
    align-items: center;
    gap: 8px;
  }

  footer {
    margin-top: 28px;
    text-align: center;
    color: var(--text-muted);
    font-size: 0.75rem;
    border-top: 1px solid var(--border-color);
    padding-top: 14px;
  }

/* Asynchronous mesh loading overlay */
.loading-overlay {
  position: absolute;
  top: 0; left: 0; right: 0; bottom: 0;
  background: rgba(4, 6, 9, 0.92);
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 16px;
  z-index: 100;
  transition: opacity 0.3s ease;
}
.spinner {
  width: 44px;
  height: 44px;
  border: 3px solid rgba(59, 130, 246, 0.2);
  border-top-color: var(--accent-blue, #3b82f6);
  border-radius: 50%;
  animation: spin 1s linear infinite;
}
@keyframes spin {
  to { transform: rotate(360deg); }
}