.ab-card {
    --ab-bg: #fff;
    --ab-border: rgba(244, 63, 94, 0.2);
    --ab-shadow: rgba(244, 63, 94, 0.08);
    --ab-sidebar-bg: rgba(255, 241, 242, 0.5);
    --ab-sidebar-border: rgba(244, 63, 94, 0.15);
    --ab-primary: #f43f5e;
    --ab-primary-hover: #e11d48;
    --ab-primary-soft: rgba(244, 63, 94, 0.05);
    --ab-primary-soft-border: rgba(244, 63, 94, 0.3);
    --ab-toggle-bg: #f1f5f9;
    --ab-toggle-text: #475569;
    --ab-group-bg: #fff;
    --ab-group-border: #e2e8f0;
    --ab-text: #0f172a;
    --ab-text-muted: #475569;
    --ab-text-secondary: #334155;
    --ab-text-label: #334155;
    --ab-input-border: #cbd5e1;
    --ab-input-bg: #fff;
    --ab-canvas-bg: #f8fafc;
    --ab-canvas-border: #cbd5e1;
    --ab-conf-track: #e2e8f0;
    --ab-sig-bg: linear-gradient(135deg, rgba(16,185,129,0.05), rgba(209,250,229,0.4));
    --ab-sig-border: rgba(16, 185, 129, 0.3);
    --ab-sig-value: #059669;
    --ab-sig-desc: #047857;
    --ab-nosig-bg: linear-gradient(135deg, rgba(239,68,68,0.05), rgba(254,226,226,0.4));
    --ab-nosig-border: rgba(239, 68, 68, 0.3);
    --ab-nosig-value: #dc2626;
    --ab-nosig-desc: #b91c1c;
    --ab-alert-bg: #fffbeb;
    --ab-alert-border: #fde68a;
    --ab-alert-title: #d97706;
    --ab-alert-body: #92400e;
    --ab-alert-link: #b45309;
    --ab-pval-title: #475569;
    --ab-pval-value: #0f172a;
    --ab-lift-header: #334155;
    --ab-lift-value: #0f172a;
    --ab-lift-text: #475569;
    --ab-copy-header: #e11d48;
    --ab-copy-text: #1e293b;

    display: flex;
    flex-direction: column;
    background: var(--ab-bg);
    border-radius: 1.5rem;
    border: 1px solid var(--ab-border);
    box-shadow: 0 10px 40px var(--ab-shadow);
    overflow: hidden;
    margin: 2rem 0;
  }

  .theme-dark .ab-card {
    --ab-bg: #18181b;
    --ab-border: rgba(251, 113, 133, 0.2);
    --ab-shadow: rgba(244, 63, 94, 0.1);
    --ab-sidebar-bg: rgba(39, 39, 42, 0.8);
    --ab-sidebar-border: rgba(251, 113, 133, 0.15);
    --ab-primary: #fb7185;
    --ab-primary-hover: #f43f5e;
    --ab-primary-soft: rgba(251, 113, 133, 0.07);
    --ab-primary-soft-border: rgba(251, 113, 133, 0.25);
    --ab-toggle-bg: #27272a;
    --ab-toggle-text: #a1a1aa;
    --ab-group-bg: #27272a;
    --ab-group-border: #3f3f46;
    --ab-text: #f4f4f5;
    --ab-text-muted: #a1a1aa;
    --ab-text-secondary: #d4d4d8;
    --ab-text-label: #d4d4d8;
    --ab-input-border: #52525b;
    --ab-input-bg: #3f3f46;
    --ab-canvas-bg: #27272a;
    --ab-canvas-border: #3f3f46;
    --ab-conf-track: #3f3f46;
    --ab-sig-bg: linear-gradient(135deg, rgba(16,185,129,0.08), rgba(6,78,59,0.2));
    --ab-sig-border: rgba(16, 185, 129, 0.25);
    --ab-sig-value: #34d399;
    --ab-sig-desc: #6ee7b7;
    --ab-nosig-bg: linear-gradient(135deg, rgba(239,68,68,0.08), rgba(127,29,29,0.2));
    --ab-nosig-border: rgba(239, 68, 68, 0.25);
    --ab-nosig-value: #f87171;
    --ab-nosig-desc: #fca5a5;
    --ab-alert-bg: #27272a;
    --ab-alert-border: #52525b;
    --ab-alert-title: #fbbf24;
    --ab-alert-body: #d4d4d8;
    --ab-alert-link: #fb923c;
    --ab-pval-title: #a1a1aa;
    --ab-pval-value: #f4f4f5;
    --ab-lift-header: #d4d4d8;
    --ab-lift-value: #f4f4f5;
    --ab-lift-text: #a1a1aa;
    --ab-copy-header: #fb7185;
    --ab-copy-text: #e4e4e7;
  }

  .ab-sidebar {
    background: var(--ab-sidebar-bg);
    border-bottom: 1px solid var(--ab-sidebar-border);
    padding: 1.5rem;
    display: flex;
    flex-direction: column;
    gap: 1.25rem;
  }

  @media (min-width: 768px) {
    .ab-card { flex-direction: row; }
    .ab-sidebar {
      width: 340px;
      flex-shrink: 0;
      border-bottom: none;
      border-right: 1px solid var(--ab-sidebar-border);
      gap: 1.5rem;
    }
  }

  .ab-sidebar-heading {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--ab-text);
    margin-bottom: 1.25rem;
  }
  .ab-sidebar-heading [data-icon] {
    color: var(--ab-primary);
    font-size: 1.5em;
  }

  .ab-toggle {
    display: flex;
    background: var(--ab-toggle-bg);
    border-radius: 0.75rem;
    padding: 0.25rem;
    gap: 0.25rem;
    margin-bottom: 0.5rem;
  }
  .ab-toggle-btn {
    flex: 1;
    padding: 0.5rem;
    border-radius: 0.5rem;
    border: none;
    background: transparent;
    color: var(--ab-toggle-text);
    font-size: 0.85rem;
    font-weight: 700;
    cursor: pointer;
    transition: all 0.2s ease;
  }
  .ab-toggle-btn.active {
    background: var(--ab-primary);
    color: #fff;
    box-shadow: 0 2px 4px rgba(244, 63, 94, 0.2);
  }

  .ab-group {
    background: var(--ab-group-bg);
    border: 1px solid var(--ab-group-border);
    border-radius: 1rem;
    padding: 1rem;
    display: flex;
    flex-direction: column;
    gap: 1rem;
  }
  .ab-group-title {
    font-weight: 800;
    font-size: 0.95rem;
    display: flex;
    align-items: center;
    gap: 0.4rem;
    color: var(--ab-text-muted);
  }
  .ab-group-title-b { color: var(--ab-primary); }

  .ab-input-row {
    display: flex;
    flex-direction: column;
    gap: 0.35rem;
  }
  .ab-input-row label {
    font-size: 0.8rem;
    font-weight: 700;
    color: var(--ab-text-label);
    display: flex;
    justify-content: space-between;
  }
  .ab-math {
    font-style: italic;
    font-weight: 600;
    color: var(--ab-text-muted);
  }
  .ab-input-row input,
  .ab-select {
    width: 100%;
    padding: 0.6rem 0.75rem;
    border-radius: 0.5rem;
    border: 1px solid var(--ab-input-border);
    background: var(--ab-input-bg);
    color: var(--ab-text);
    font-size: 0.95rem;
    font-weight: 600;
    transition: all 0.2s;
  }
  .ab-input-row input:focus,
  .ab-select:focus {
    outline: none;
    border-color: var(--ab-primary);
    box-shadow: 0 0 0 2px rgba(244, 63, 94, 0.15);
  }
  .ab-direction-row { margin-top: 0.75rem; }

  .ab-main {
    flex: 1;
    display: flex;
    flex-direction: column;
    padding: 1.5rem;
    gap: 2rem;
  }

  .ab-alert {
    background: var(--ab-alert-bg);
    border: 1px solid var(--ab-alert-border);
    padding: 1rem;
    border-radius: 0.75rem;
  }
  .ab-alert-title {
    color: var(--ab-alert-title);
    font-weight: 800;
    font-size: 0.9rem;
    margin-bottom: 0.25rem;
  }
  .ab-alert-body {
    color: var(--ab-alert-body);
    font-size: 0.85rem;
    margin: 0;
    font-weight: 500;
  }
  .ab-alert-link {
    color: var(--ab-alert-link);
    text-decoration: underline;
    font-weight: 700;
  }

  .ab-results-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 1rem;
  }

  @media (min-width: 640px) {
    .ab-results-grid { grid-template-columns: auto 1fr; }
  }

  .ab-pvalue-block {
    background: var(--ab-canvas-bg);
    border: 1px solid var(--ab-group-border);
    border-radius: 1rem;
    padding: 1.5rem;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    text-align: center;
    transition: all 0.3s;
  }
  .ab-pvalue-block.significant {
    background: var(--ab-sig-bg);
    border-color: var(--ab-sig-border);
  }
  .ab-pvalue-block.not-significant {
    background: var(--ab-nosig-bg);
    border-color: var(--ab-nosig-border);
  }
  .ab-pval-title {
    font-size: 0.9rem;
    font-weight: 700;
    color: var(--ab-pval-title);
    margin-bottom: 0.5rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
  }
  .ab-pval-value {
    font-size: 3.5rem;
    font-weight: 800;
    line-height: 1;
    color: var(--ab-pval-value);
  }
  .significant .ab-pval-value { color: var(--ab-sig-value); }
  .not-significant .ab-pval-value { color: var(--ab-nosig-value); }
  .ab-pval-desc {
    font-size: 1rem;
    font-weight: 700;
    margin-top: 0.75rem;
    max-width: 200px;
    color: var(--ab-text-muted);
  }
  .significant .ab-pval-desc { color: var(--ab-sig-desc); }
  .not-significant .ab-pval-desc { color: var(--ab-nosig-desc); }

  .ab-lift-block {
    background: var(--ab-canvas-bg);
    border: 1px solid var(--ab-group-border);
    border-radius: 1rem;
    padding: 1.5rem;
    display: flex;
    flex-direction: column;
    justify-content: center;
  }
  .ab-lift-header {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.9rem;
    font-weight: 700;
    color: var(--ab-lift-header);
    margin-bottom: 1rem;
  }
  .ab-lift-header [data-icon] { color: var(--ab-primary); }
  .ab-lift-content {
    display: flex;
    align-items: baseline;
    gap: 1rem;
  }
  .ab-lift-value {
    font-size: 2.5rem;
    font-weight: 800;
    color: var(--ab-lift-value);
  }
  .ab-lift-value.positive { color: var(--ab-sig-value); }
  .ab-lift-value.negative { color: var(--ab-nosig-value); }
  .ab-lift-text {
    font-size: 1rem;
    font-weight: 500;
    color: var(--ab-lift-text);
  }
  .ab-conf-bar-wrap {
    margin-top: 1.5rem;
    background: var(--ab-conf-track);
    height: 12px;
    border-radius: 6px;
    overflow: hidden;
  }
  .ab-conf-bar-fill {
    height: 100%;
    background: var(--ab-primary);
    width: 0%;
    transition: width 0.5s cubic-bezier(0.4, 0, 0.2, 1);
  }
  .ab-conf-text {
    font-size: 0.8rem;
    font-weight: 700;
    color: var(--ab-text-muted);
    margin-top: 0.5rem;
    text-align: right;
  }

  .ab-visual {
    background: var(--ab-group-bg);
    border: 1px solid var(--ab-group-border);
    border-radius: 1rem;
    padding: 1.5rem;
  }
  .ab-block-title {
    font-size: 0.9rem;
    font-weight: 700;
    color: var(--ab-text-secondary);
    margin-bottom: 0.5rem;
    display: flex;
    align-items: center;
    gap: 0.4rem;
  }
  .ab-block-title [data-icon] { color: var(--ab-primary); }
  .ab-chart-desc {
    font-size: 0.85rem;
    color: var(--ab-text-muted);
    margin-bottom: 1rem;
    font-weight: 500;
  }
  #curves-canvas {
    width: 100%;
    height: 240px;
    display: block;
    background: var(--ab-canvas-bg);
    border-radius: 0.75rem;
    border: 1px dashed var(--ab-canvas-border);
  }

  .ab-copy-block {
    background: var(--ab-primary-soft);
    border: 1px dashed var(--ab-primary-soft-border);
    border-radius: 1rem;
    padding: 1.5rem;
    position: relative;
  }
  .ab-copy-header {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--ab-copy-header);
    font-weight: 800;
    font-size: 0.9rem;
    margin-bottom: 0.5rem;
  }
  .ab-copy-text {
    font-size: 1.05rem;
    line-height: 1.6;
    color: var(--ab-copy-text);
    margin: 0;
    font-style: italic;
    font-weight: 500;
  }
  .ab-copy-btn {
    position: absolute;
    bottom: 1.25rem;
    right: 1.5rem;
    background: var(--ab-primary);
    color: #fff;
    border: none;
    border-radius: 0.5rem;
    padding: 0.5rem 0.75rem;
    font-size: 0.75rem;
    font-weight: 700;
    display: flex;
    align-items: center;
    gap: 0.25rem;
    cursor: pointer;
    transition: background 0.2s;
  }
  .ab-copy-btn:hover { background: var(--ab-primary-hover); }

  @media (max-width: 600px) {
    .ab-card {
      border-radius: 1rem;
      margin: 0;
    }
    .ab-sidebar { padding: 1.25rem; }
    .ab-main {
      padding: 1.25rem;
      gap: 1.25rem;
    }
    .ab-pval-value { font-size: 2.5rem; }
    .ab-pval-desc {
      font-size: 0.875rem;
      max-width: unset;
    }
    .ab-lift-value { font-size: 1.75rem; }
    .ab-lift-text { font-size: 0.875rem; }
    .ab-lift-content {
      gap: 0.5rem;
      flex-wrap: wrap;
    }
    .ab-visual { padding: 1rem; }
    #curves-canvas { height: 180px; }
    .ab-copy-block {
      padding: 1rem;
      padding-bottom: 4rem;
    }
    .ab-copy-text { font-size: 0.9rem; }
  }