/* ────────────────────────────────────
     GLOBAL RESET & FONTS
     ──────────────────────────────────── */
  *, *::before, *::after { margin:0; padding:0; box-sizing:border-box; }

  html {
    scroll-behavior: smooth;
    
    font-family: 'Inter', system-ui, -apple-system, 'Segoe UI', Roboto, sans-serif;
    background: #f8f9fc;
    color: #1e1f2b;
    -webkit-font-smoothing: antialiased;
  }

  /* ────────────────────────────────────
     HEADER / TEXT SECTION
     ──────────────────────────────────── */
  .page {
    width: 100%;
    max-width: 1400px;
    margin: 0 auto;
    padding: 40px 20px 20px;
  }

  .badge {
    display: inline-block;
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.18em;
    color: #7c3aed;
    background: rgba(124,58,237,0.08);
    padding: 6px 14px;
    border-radius: 99px;
    margin-bottom: 14px;
  }

  .title {
    font-size: clamp(1.75rem, 5vw, 3rem);
    font-weight: 800;
    line-height: 1.15;
    margin-bottom: 10px;
    color: #0f0f1a;
  }

  .desc {
    max-width: 700px;
    font-size: clamp(0.9rem, 2vw, 1.1rem);
    line-height: 1.7;
    color: #5b5d6e;
    margin-bottom: 24px;
  }

  .chips {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin-bottom: 14px;
  }
  .chip {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    font-size: 0.8rem;
    font-weight: 500;
    color: #4a4c5c;
    background: #fff;
    border: 1px solid #e2e4ed;
    padding: 6px 14px;
    border-radius: 99px;
    white-space: nowrap;
  }

  /* ────────────────────────────────────
     3D VIEWER CONTAINER
     ──────────────────────────────────── */
  .viewer-wrap {
    position: relative;
    width: 100%;
    height: 55vh;
    min-height: 340px;
    border-radius: 20px;
    overflow: hidden;
    background: #0f0f14;
    box-shadow:
      0 4px 32px rgba(124,58,237,0.08),
      0 1px 4px rgba(0,0,0,0.06);
    border: 1px solid rgba(0,0,0,0.06);
  }

  #viewer-canvas {
    display: block;
    width: 100%;
    height: 100%;
  }

  /* ────────────────────────────────────
     LOADING SPINNER
     ──────────────────────────────────── */
  #loading-overlay {
    position: absolute;
    inset: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    background: #0f0f14;
    z-index: 10;
    transition: opacity 0.45s ease;
    pointer-events: none;
    border-radius: 20px;
  }
  #loading-overlay.hidden { opacity: 0; }

  .spinner {
    width: 40px; height: 40px;
    border: 3px solid rgba(255,255,255,0.1);
    border-top-color: #8b5cf6;
    border-radius: 50%;
    animation: spin 0.75s linear infinite;
  }
  @keyframes spin { to { transform:rotate(360deg) } }

  /* ────────────────────────────────────
     HINT TEXT
     ──────────────────────────────────── */
  #hint-bar {
    position: absolute;
    bottom: 16px;
    left: 50%;
    transform: translateX(-50%);
    color: rgba(255,255,255,0.5);
    font-size: 0.7rem;
    letter-spacing: 0.04em;
    pointer-events: none;
    z-index: 5;
    transition: opacity 1.4s;
    white-space: nowrap;
  }

  /* ────────────────────────────────────
     TOOLBAR BUTTONS
     ──────────────────────────────────── */
  #toolbar {
    position: absolute;
    top: 12px;
    right: 12px;
    display: flex;
    gap: 6px;
    z-index: 6;
  }
  #toolbar button {
    width: 34px; height: 34px;
    border-radius: 8px;
    border: 1px solid rgba(255,255,255,0.1);
    background: rgba(20,20,32,0.75);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    color: rgba(255,255,255,0.7);
    cursor: pointer;
    font-size: 15px;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.2s;
  }
  #toolbar button:hover {
    background: rgba(255,255,255,0.18);
    color: #fff;
    border-color: rgba(255,255,255,0.3);
  }
  #toolbar button.active {
    background: #7c3aed;
    border-color: #7c3aed;
    color: #fff;
  }

  /* ────────────────────────────────────
     RESPONSIVE BREAKPOINTS
     ──────────────────────────────────── */
  @media (min-width: 600px) {
    .page { padding: 50px 28px 24px; }
    .viewer-wrap { height: 62vh; min-height: 420px; }
    #hint-bar { font-size: 0.75rem; }
  }

  @media (min-width: 900px) {
    .page { padding: 60px 40px 30px; }
    .viewer-wrap { height: 72vh; min-height: 500px; border-radius: 24px; }
    #hint-bar { font-size: 0.8rem; bottom: 20px; }
    .chip { font-size: 0.85rem; padding: 7px 16px; }
  }

  @media (min-width: 1300px) {
    .viewer-wrap { height: 78vh; min-height: 560px; }
  }

  /* small phones */
  @media (max-width: 399px) {
    .page { padding: 24px 12px 12px; }
    .viewer-wrap { height: 50vh; min-height: 280px; border-radius: 14px; }
    #toolbar { top: 8px; right: 8px; gap: 4px; }
    #toolbar button { width: 30px; height: 30px; font-size: 13px; }
    #hint-bar { bottom: 10px; font-size: 0.65rem; }
    .chip { font-size: 0.7rem; padding: 4px 10px; }
  }