.container {
    max-width: 580px;
  }

  .settings-section-title {
    font-size: 1.25rem;
    margin-bottom: var(--s-md);
  }

  .checkbox-label {
    display: flex;
    align-items: center;
    gap: var(--s-sm);
  }

  .checkbox-label input[type="checkbox"] {
    width: auto;
  }

  .settings-input {
    width: 100%;
    padding: 10px 14px;
    border: 1px solid var(--border);
    border-radius: 8px;
  }

  .theme-section-title {
    font-size: var(--text-sm);
    font-weight: 600;
    color: var(--mid-gray);
    margin: var(--s-xl) 0 var(--s-md) 0;
    text-transform: uppercase;
    letter-spacing: var(--ls-normal);
  }

  .theme-section-title:first-child {
    margin-top: 0;
  }

  .preset-selector {
    margin-bottom: var(--s-xl);
    padding-bottom: var(--s-xl);
    border-bottom: 1px solid var(--mid-gray-light);
  }

  .preset-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: var(--s-sm);
  }

  .preset-card {
    padding: var(--s-sm);
    border: 2px solid var(--mid-gray-light);
    border-radius: 0;
    cursor: pointer;
    transition: all 0.15s ease;
    background: var(--white);
    text-align: center;
  }

  .preset-card:hover {
    border-color: var(--dark-gray);
  }

  .preset-card.active {
    border-color: var(--blue);
    box-shadow: var(--focus-ring);
  }

  .preset-colors {
    display: flex;
    gap: 2px;
    margin-bottom: var(--s-xs);
    justify-content: center;
  }

  .preset-color-dot {
    width: 12px;
    height: 12px;
    border-radius: 50%;
    border: 1px solid rgba(0,0,0,0.1);
  }

  .preset-name {
    font-size: var(--text-xs);
    font-weight: 600;
    color: var(--black);
    margin-bottom: 2px;
  }

  .preset-desc {
    font-size: 0.65rem;
    color: var(--mid-gray);
    line-height: 1.2;
    display: none;
  }

  @media (max-width: 500px) {
    .preset-grid {
      grid-template-columns: repeat(2, 1fr);
    }
  }

  .color-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--s-md) var(--s-md);
  }

  .color-grid .form-group {
    margin-bottom: 0;
  }

  .color-grid .help-text {
    font-size: 0.7rem;
  }

  .color-input-row {
    display: flex;
    gap: var(--s-sm);
    align-items: center;
  }

  .color-input-row input[type="color"] {
    width: 40px;
    height: 32px;
    padding: 2px;
    border: 1px solid var(--mid-gray-light);
    border-radius: 0;
    cursor: pointer;
    background: var(--white);
  }

  .color-input-row input[type="color"]::-webkit-color-swatch-wrapper {
    padding: 2px;
  }

  .color-input-row input[type="color"]::-webkit-color-swatch {
    border: none;
    border-radius: 0;
  }

  .color-hex-input {
    width: 80px !important;
    font-family: var(--font-ui);
    font-size: var(--text-xs);
    text-transform: uppercase;
    padding: var(--s-sm) !important;
  }

  .theme-preview {
    margin-top: var(--s-xl);
    padding: var(--s-md);
    background: var(--white);
    border: 2px solid var(--black);
    border-radius: 0;
  }

  .preview-label {
    font-size: var(--text-xs);
    text-transform: uppercase;
    letter-spacing: var(--ls-normal);
    color: var(--mid-gray);
    margin-bottom: var(--s-md);
  }

  .preview-buttons {
    display: flex;
    gap: var(--s-sm);
    flex-wrap: wrap;
    align-items: center;
    margin-bottom: var(--s-md);
  }

  .preview-phases {
    display: flex;
    gap: var(--s-sm);
    flex-wrap: wrap;
  }

  .phase-pill {
    padding: var(--s-xs) var(--s-md);
    border-radius: 0;
    font-size: var(--text-xs);
    font-weight: 600;
    color: white;
  }

  .preview-heatmap {
    margin-top: var(--s-md);
  }

  .preview-heatmap-label {
    font-size: var(--text-xs);
    color: var(--mid-gray);
    margin-bottom: var(--s-sm);
  }

  .preview-heatmap-grid {
    display: flex;
    gap: 3px;
  }

  .preview-heatmap-week {
    display: flex;
    flex-direction: column;
    gap: 3px;
  }

  .preview-heatmap-cell {
    width: 10px;
    height: 10px;
    border-radius: 0;
  }

  .preview-heatmap-cell.level-0 { background: var(--heatmap-empty, var(--warm-gray)); }
  .preview-heatmap-cell.level-1 { background: var(--heatmap-l1, #9be9a8); }
  .preview-heatmap-cell.level-2 { background: var(--heatmap-l2, #40c463); }
  .preview-heatmap-cell.level-3 { background: var(--heatmap-l3, #30a14e); }
  .preview-heatmap-cell.level-4 { background: var(--heatmap-l4, #216e39); }

  .phase-pill.opening {
    background: var(--color-phase-opening);
  }

  .phase-pill.middlegame {
    background: var(--color-phase-middlegame);
  }

  .phase-pill.endgame {
    background: var(--color-phase-endgame);
  }

  .preview-primary {
    background: var(--blue) !important;
    border-color: var(--blue) !important;
  }

  .preview-success {
    background: var(--correct) !important;
    border-color: var(--correct) !important;
  }

  .preview-error {
    background: var(--red) !important;
    border-color: var(--red) !important;
  }

  /* Board styling */
  .board-preview-container {
    display: flex;
    gap: var(--s-md);
    align-items: flex-start;
  }

  .board-preview {
    width: 160px;
    height: 160px;
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    grid-template-rows: repeat(4, 1fr);
    border-radius: 0;
    overflow: hidden;
    border: 2px solid var(--black);
    flex-shrink: 0;
  }

  .board-preview .square {
    display: flex;
    align-items: center;
    justify-content: center;
  }

  .board-preview .square img {
    width: 80%;
    height: 80%;
    object-fit: contain;
  }

  .board-preview .square.light {
    background: var(--preview-board-light, #f0d9b5);
  }

  .board-preview .square.dark {
    background: var(--preview-board-dark, #b58863);
  }

  .board-settings-controls {
    flex: 1;
  }

  .piece-set-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--s-sm);
    margin-bottom: var(--s-md);
  }

  .piece-set-card {
    padding: var(--s-sm) var(--s-md);
    border: 2px solid var(--mid-gray-light);
    border-radius: 0;
    cursor: pointer;
    transition: all 0.15s ease;
    background: var(--white);
    text-align: center;
    font-size: var(--text-sm);
    font-weight: 500;
  }

  .piece-set-card:hover {
    border-color: var(--dark-gray);
  }

  .piece-set-card.active {
    border-color: var(--blue);
    box-shadow: var(--focus-ring);
  }

  .board-color-presets {
    display: flex;
    flex-wrap: wrap;
    gap: var(--s-sm);
    margin-bottom: var(--s-md);
  }

  .board-color-preset {
    width: 40px;
    height: 40px;
    border-radius: 0;
    cursor: pointer;
    border: 2px solid var(--mid-gray-light);
    overflow: hidden;
    transition: all 0.15s ease;
    display: grid;
    grid-template-columns: 1fr 1fr;
    grid-template-rows: 1fr 1fr;
  }

  .board-color-preset:hover {
    transform: scale(1.1);
  }

  .board-color-preset.active {
    border-color: var(--blue);
    box-shadow: var(--focus-ring);
  }

  .board-color-preset .light {
    grid-column: 1;
    grid-row: 1;
  }

  .board-color-preset .dark {
    grid-column: 2;
    grid-row: 2;
  }

  .board-color-preset .light-alt {
    grid-column: 2;
    grid-row: 1;
  }

  .board-color-preset .dark-alt {
    grid-column: 1;
    grid-row: 2;
  }

  .board-custom-colors {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--s-md);
  }

/* Feature toggles */
.feature-toggles {
  display: flex;
  flex-direction: column;
  gap: var(--s-xl);
}

.feature-group-title {
  font-family: var(--font-ui);
  font-weight: 600;
  font-size: var(--text-base);
  color: var(--mid-gray);
  text-transform: uppercase;
  letter-spacing: var(--ls-normal);
  margin-bottom: var(--s-sm);
}

.feature-toggle-row {
  display: flex;
  align-items: center;
  gap: var(--s-sm);
  padding: var(--s-xs) 0;
  cursor: pointer;
  font-size: var(--text-base);
}

.feature-toggle-row input[type="checkbox"] {
  width: auto;
}

.status.preview-warning {
  background: var(--color-warning-bg);
  color: var(--color-warning);
}