.card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: var(--sp-4);
    position: relative;
    overflow: visible;
  }

  .grid-2 { display: grid; grid-template-columns: 1fr 1fr; gap: var(--sp-4); }
  .grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: var(--sp-4); }

  .obj-list {
    list-style: none;
    margin: var(--sp-3) 0;
  }

  .obj-list li {
    padding: var(--sp-3) var(--sp-4) var(--sp-3) 2.5rem;
    border-radius: var(--radius-sm);
    margin-bottom: var(--sp-2);
    font-size: var(--fs-base);
    line-height: 1.5;
    background: var(--surface2);
    border: 1px solid var(--border);
    position: relative;
  }

  .obj-list li::before {
    content: attr(data-num);
    position: absolute;
    left: var(--sp-3);
    top: var(--sp-3);
    font-family: 'JetBrains Mono', monospace;
    font-size: var(--fs-xs);
    font-weight: 700;
    color: var(--accent);
  }

  .callout {
    display: flex;
    gap: var(--sp-3);
    padding: var(--sp-3) var(--sp-4);
    border-radius: var(--radius-md);
    font-size: var(--fs-base);
    line-height: 1.55;
  }

  .callout .icon { flex-shrink: 0; font-size: var(--fs-lg); }
  .callout.info     { background: var(--accent-bg);  border: 1px solid var(--accent-border); color: #0f1a60; }
  .callout.warn     { background: var(--orange-bg);  border: 1px solid var(--orange-border); color: #5e2a00; }
  .callout.success  { background: var(--green-bg);   border: 1px solid var(--green-border);  color: #084020; }
  .callout.question { background: var(--purple-bg);  border: 1px solid var(--purple-border); color: #2e1a80; }

  .flow {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--sp-3);
    flex-wrap: wrap;
    margin: var(--sp-4) 0;
  }

  .flow-box {
    padding: var(--sp-3) var(--sp-4);
    border-radius: var(--radius-md);
    font-size: var(--fs-base);
    font-weight: 600;
    text-align: center;
    border: 1px solid var(--border);
    background: var(--surface);
    min-width: 7rem;
  }

  .flow .flow-box ~ .flow-box {
    position: relative;
    margin-left: 1.5rem;
  }

  .flow .flow-box ~ .flow-box::before {
    content: '\2192';
    position: absolute;
    right: calc(100% + 0.25rem);
    top: 50%;
    transform: translateY(-50%);
    color: var(--text-dim);
    font-size: 1.3rem;
    pointer-events: none;
  }

  .hidden-content {
    max-height: 0;
    overflow: hidden;
    opacity: 0;
    margin-top: 0;
    transition: max-height 0.45s ease, opacity 0.35s ease, margin-top 0.35s ease;
  }

  .hidden-content.revealed {
    max-height: 32rem;
    opacity: 1;
    margin-top: var(--sp-3);
  }

  .hidden-content.revealed.settled {
    max-height: none;
    overflow: visible;
  }

  .template-note {
    margin-top: var(--sp-3);
    border: 1px dashed var(--accent-border);
    border-radius: var(--radius-md);
    padding: var(--sp-3);
    color: #0f1a60;
    font-size: var(--fs-sm);
    background: rgba(42,79,214,0.07);
  }

  .nav-btn {
    font-family: 'Inter', sans-serif;
    font-size: 0.72rem;
    font-weight: 600;
    padding: 0.19rem 0.70rem;
    border-radius: var(--radius-sm);
    border: 1px solid var(--border);
    background: var(--surface2);
    color: var(--text);
    cursor: pointer;
    transition: all 0.2s;
    white-space: nowrap;
  }

  .nav-btn:hover { background: var(--border); }

  .nav-btn.primary {
    background: var(--accent);
    border-color: var(--accent);
    color: #fff;
  }
  .nav-btn.primary:hover { background: #1a3aa8; }

  .nav-btn:disabled { opacity: 0.4; cursor: not-allowed; }

  .bottom-bar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    position: absolute;
    left: 0;
    right: 0;
    bottom: 0;
    height: var(--deck-nav-height);
    padding: 0 0.85rem;
    box-sizing: border-box;
    background: rgba(232,236,252,0.95);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-top: 1px solid var(--border);
    z-index: 10;
    flex-shrink: 0;
  }

  .progress-track {
    flex: 1;
    height: 0.16rem;
    background: var(--surface2);
    border-radius: 0.2rem;
    margin: 0 0.85rem;
    overflow: hidden;
  }

  .progress-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--accent), var(--purple));
    border-radius: 0.2rem;
    transition: width 0.4s ease;
  }

  .slide-counter {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.68rem;
    color: var(--text-dim);
    min-width: 3.1rem;
    text-align: center;
  }

  .math { text-align: center; font-size: var(--fs-lg); margin: 0.6rem auto; }