.selector-container {
        max-width: 1000px;
        margin-left: auto;
        margin-right: auto;
      }
      .selector-sessions-history {
        margin-top: 40px;
        padding-bottom: 40px;
      }
      .sessions-history-title {
        font-size: 1.1rem;
        font-weight: 600;
        color: var(--text);
        margin: 0 0 16px 0;
      }
      .table-responsive {
        overflow-x: auto;
      }
      .sessions-history-table {
        width: 100%;
        border-collapse: collapse;
        font-size: 0.88rem;
      }
      .sessions-history-table th,
      .sessions-history-table td {
        padding: 10px 12px;
        text-align: left;
        border-bottom: 1px solid var(--border);
      }
      .sessions-history-table th {
        font-weight: 600;
        font-size: 0.78rem;
        text-transform: uppercase;
        letter-spacing: 0.05em;
        color: var(--text-secondary);
      }
      .sessions-history-table .text-right {
        text-align: right;
      }
      .sessions-history-date {
        white-space: nowrap;
      }
      .sessions-step-badge {
        display: inline-block;
        padding: 2px 7px;
        background: var(--bg-surface-alt);
        border: 1px solid var(--border);
        border-radius: var(--radius-pill);
        font-size: 0.75rem;
        font-weight: 600;
        color: var(--text-secondary);
      }
      .sessions-result {
        display: inline-block;
        padding: 2px 8px;
        border-radius: var(--radius-pill);
        font-size: 0.78rem;
        font-weight: 600;
      }
      .sessions-result--complete {
        background: color-mix(in srgb, var(--success, #22c55e) 12%, transparent);
        color: var(--success, #16a34a);
      }
      .sessions-result--ended {
        background: color-mix(in srgb, var(--text-secondary) 10%, transparent);
        color: var(--text-secondary);
      }
      .sessions-view-link {
        color: var(--primary);
        font-size: 0.82rem;
        font-weight: 500;
        text-decoration: none;
        white-space: nowrap;
      }
      .sessions-view-link:hover {
        text-decoration: underline;
      }

      /* Session Summary Page */
      .fc-summary-page {
        padding-top: 32px;
        padding-bottom: 48px;
      }
      .fc-summary-header {
        display: flex;
        justify-content: space-between;
        align-items: flex-start;
        margin-bottom: 24px;
        gap: 16px;
        flex-wrap: wrap;
      }
      .fc-summary-header__titles {
        min-width: 0;
      }
      .fc-summary-header__actions {
        flex-shrink: 0;
      }
      .fc-summary-title {
        margin: 4px 0 4px 0;
        font-size: 1.75rem;
        font-weight: 700;
        color: var(--text);
      }
      .fc-summary-meta {
        font-size: 0.88rem;
      }
      .fc-summary-badge {
        display: inline-block;
        padding: 1px 7px;
        border-radius: var(--radius-pill);
        font-size: 0.78rem;
        font-weight: 600;
      }
      .fc-summary-badge--complete {
        background: color-mix(in srgb, var(--success, #22c55e) 12%, transparent);
        color: var(--success, #16a34a);
      }
      .fc-summary-badge--ended {
        background: color-mix(in srgb, var(--text-secondary) 10%, transparent);
        color: var(--text-secondary);
      }
      .fc-summary-card {
        padding: 24px;
        margin-bottom: 16px;
      }
      .fc-summary-grid {
        margin-bottom: 24px;
      }
      .fc-summary-time {
        font-variant-numeric: tabular-nums;
        letter-spacing: 0.04em;
      }
      .fc-summary-progress {
        margin-top: 8px;
      }
      .fc-summary-actions {
        margin-top: 24px;
      }

      .selector-header {
        margin-bottom: 0;
      }
      .selector-notices {
        margin-bottom: 24px;
      }
      .selector-notices:not(:has(.flash-list)) {
        display: none;
      }
      .selector-title {
        margin: 0 0 4px 0;
        font-size: 1.75rem;
        font-weight: 700;
        color: var(--text);
      }
      .step-toggle-bar {
        display: flex;
        gap: 8px;
        margin-bottom: 16px;
      }
      .selector-columns-grid {
        display: grid;
        grid-template-columns: 1.2fr 1.2fr;
        gap: 24px;
        margin-bottom: 0;
        align-items: stretch;
      }
      @media (max-width: 992px) {
        .selector-columns-grid {
          grid-template-columns: 1fr;
        }
      }
      .selector-left-panel,
      .selector-right-stack {
        min-height: 460px;
      }
      .selector-left-panel {
        display: flex;
        flex-direction: column;
        min-height: 0;
      }
      .selector-left-panel .panel-body-scroll {
        flex: 1;
        max-height: none;
        min-height: 0;
      }
      .selector-right-stack {
        display: flex;
        flex-direction: column;
        gap: 12px;
        min-height: 0;
      }
      .selector-right-panel {
        flex: 1;
        min-height: 0;
        display: flex;
        flex-direction: column;
        margin-bottom: 0;
      }
      .selector-right-panel .panel-body-scroll {
        flex: 1;
        max-height: none;
        min-height: 0;
      }
      @media (min-width: 993px) {
        .selector-left-panel,
        .selector-right-stack {
          height: calc(100vh - var(--header-height, 64px) - var(--site-footer-height, 52px) - 270px);
          min-height: 380px;
          max-height: 640px;
        }
      }
      .selector-action-bar {
        flex-shrink: 0;
        display: flex;
        justify-content: flex-end;
        align-items: center;
        gap: 16px;
        flex-wrap: wrap;
        padding: 4px 0 0;
      }
      .selector-action-count {
        font-weight: 600;
        font-size: 1rem;
      }
      .filter-panel-card {
        padding: 20px;
        margin-bottom: 0;
        display: flex;
        flex-direction: column;
      }
      .panel-header-row {
        display: flex;
        align-items: center;
        justify-content: space-between;
        gap: 12px;
        margin-bottom: 16px;
      }
      .panel-header {
        margin: 0;
        font-size: 1.25rem;
        font-weight: 600;
        color: var(--text);
      }
      .fc-panel-select-toggle {
        width: 18px;
        height: 18px;
        margin: 0;
        flex-shrink: 0;
        cursor: pointer;
        accent-color: var(--accent-blue);
      }
      .system-row.is-disabled,
      .subtopic-row.is-disabled {
        opacity: 0.45;
        cursor: not-allowed;
        pointer-events: none;
      }
      .system-row.is-disabled:hover,
      .subtopic-row.is-disabled:hover {
        background-color: transparent;
      }
      .panel-body-scroll {
        max-height: 400px;
        overflow-y: auto;
        padding-right: 8px;
        display: flex;
        flex-direction: column;
        gap: 12px;
      }
      .category-row-container {
        border-bottom: 1px solid var(--border);
        padding-bottom: 12px;
      }
      .category-row-container:last-child {
        border-bottom: none;
        padding-bottom: 0;
      }
      .category-row {
        display: flex;
        align-items: center;
        justify-content: space-between;
        gap: 12px;
      }
      .category-name {
        font-weight: 500;
        color: var(--text);
        font-size: 0.95rem;
      }
      .chevron-btn {
        background: transparent;
        border: none;
        color: var(--muted);
        cursor: pointer;
        font-size: 1.2rem;
        padding: 0 4px;
        display: flex;
        align-items: center;
        justify-content: center;
        transition: transform 0.2s ease;
      }
      .chevron-btn.is-active {
        transform: rotate(90deg);
      }
      .accordion-content {
        max-height: 0;
        overflow: hidden;
        transition: max-height 0.3s cubic-bezier(0.4, 0, 0.2, 1), opacity 0.3s ease;
        opacity: 0;
        padding-left: 24px;
        display: flex;
        flex-direction: column;
        gap: 8px;
      }
      .accordion-content.is-open {
        max-height: 1000px;
        opacity: 1;
        margin-top: 8px;
      }
      .system-row {
        display: flex;
        align-items: center;
        justify-content: space-between;
        padding: 10px 12px;
        border-radius: var(--radius-sm);
        cursor: pointer;
        transition: background-color var(--duration-fast) var(--ease-standard);
        gap: 8px;
        user-select: none;
      }
      .system-row:hover {
        background-color: var(--bg-surface-alt);
      }
      .system-row-left {
        display: flex;
        align-items: center;
        gap: 8px;
        flex-grow: 1;
      }
      .system-row-meta {
        font-size: 0.9rem;
        color: var(--text-secondary);
      }
      .subtopic-row {
        display: flex;
        align-items: center;
        justify-content: space-between;
        padding: 10px 12px;
        gap: 8px;
        user-select: none;
      }
      .subtopic-row-left {
        display: flex;
        align-items: center;
        gap: 8px;
        flex-grow: 1;
      }
      .subtopic-row-meta {
        font-size: 0.9rem;
        color: var(--text-secondary);
      }
      .start-study-btn {
        padding: 0 32px;
        height: 46px;
        font-size: 1.05rem;
      }
      #fc-start:disabled {
        opacity: 0.4 !important;
        cursor: not-allowed !important;
        pointer-events: none !important;
        filter: none !important;
      }
      .checkbox-grid-custom {
        display: flex;
        flex-direction: column;
        gap: 12px;
        width: 100%;
      }
      .nbme-row {
        padding: 4px 0;
      }
      .filter-row-grid {
        display: flex;
        flex-wrap: wrap;
        align-items: flex-start;
        gap: 20px 120px;
      }
      .fc-filter-bar {
        padding: 16px 24px;
        margin-bottom: 24px;
        border: 1px solid var(--border);
        border-radius: var(--radius-md);
        background-color: var(--bg-surface);
      }
      .fc-filter-bar-group {
        display: flex;
        flex-direction: column;
        gap: 8px;
        flex: 0 0 auto;
      }
      .fc-filter-bar-group--filters {
        flex: 1 1 280px;
        min-width: 0;
      }
      .fc-filter-bar-label {
        margin: 0;
        font-weight: 600;
        color: var(--text-secondary);
        font-size: 0.85rem;
        text-transform: uppercase;
        letter-spacing: 0.05em;
        line-height: 1.2;
        white-space: nowrap;
      }
      .fc-filter-bar-controls {
        display: flex;
        align-items: center;
        min-height: 38px;
      }
      .fc-filter-bar-controls--filters {
        gap: 24px;
        flex-wrap: wrap;
      }
      .fc-filter-checkbox {
        display: flex;
        align-items: center;
        gap: 8px;
        margin: 0;
        padding: 0;
        border: none;
        background: transparent;
        cursor: pointer;
        user-select: none;
      }
      .fc-filter-checkbox input[type="checkbox"] {
        width: 18px;
        height: 18px;
        margin: 0;
        cursor: pointer;
        accent-color: var(--accent-blue);
      }
      .fc-filter-checkbox span {
        font-weight: 500;
        font-size: 0.95rem;
        color: var(--text);
        white-space: nowrap;
      }
      .fc-filter-count {
        color: var(--muted);
        font-size: 0.85rem;
        font-weight: normal;
      }
      .fc-limit-input {
        width: 88px;
        height: 38px;
        padding: 0 12px;
        border-radius: var(--radius-sm);
        border: 1px solid var(--border);
        background-color: var(--bg-surface);
        color: var(--text);
        font-weight: 600;
        font-size: 0.95rem;
        box-sizing: border-box;
      }
      @media (max-width: 768px) {
        .filter-row-grid {
          flex-direction: column;
          gap: 20px;
        }
        .fc-filter-bar-group--filters {
          flex-basis: auto;
          width: 100%;
        }
        .fc-filter-bar-controls--filters {
          gap: 16px;
        }
      }
      :root {
        --color-rating-reviewed: rgba(22, 163, 74, 0.12);   /* subtle green tint */
        --color-rating-flag: rgba(255, 193, 7, 0.12);       /* subtle amber/yellow tint */
      }

      .session-container {
        display: flex;
        align-items: center;
        justify-content: center;
        min-height: calc(100vh - var(--header-height) - var(--footer-height) - 96px);
        box-sizing: border-box;
        width: 100%;
      }

      .card-study {
        max-width: 720px;
        width: 100%;
        margin: 32px auto;
        padding: 0 !important;
        overflow: hidden;
      }

      .session-loading {
        text-align: center;
        padding: 48px 0;
        width: 100%;
      }

      /* Card Meta Bar */
      .card-meta-bar {
        display: flex;
        justify-content: space-between;
        align-items: center;
        padding: 16px 24px;
        border-bottom: 1px solid var(--border);
        background-color: var(--bg-surface);
      }
      .meta-left {
        display: flex;
        align-items: center;
        gap: 10px;
      }
      .meta-right {
        display: flex;
        align-items: center;
        gap: 16px;
      }

      /* NBME badge */
      .nbme-badge {
        display: inline-flex;
        align-items: center;
        padding: 4px 10px;
        background-color: var(--bg-surface-alt);
        border: 1px solid var(--border);
        border-radius: var(--radius-pill);
        font-size: 0.8rem;
        font-weight: 600;
        color: var(--text-secondary);
        user-select: none;
      }

      /* Session stopwatch timer */
      .fc-timer {
        font-size: 0.85rem;
        font-weight: 600;
        font-variant-numeric: tabular-nums;
        color: var(--text-secondary);
        letter-spacing: 0.03em;
        user-select: none;
      }

      /* .btn--danger-outline and .btn--undo moved to style.css (shared .btn modifiers) */

      /* Linear Progress Bar (bleeding edge-to-edge) */
      .linear-progress-container {
        width: 100%;
        height: 4px;
        background-color: var(--bg-surface-alt);
        position: relative;
        overflow: hidden;
      }
      .linear-progress-fill {
        height: 100%;
        width: 0%;
        background-color: var(--brand);
        border-radius: var(--radius-pill);
        transition: width 0.3s ease;
      }

      /* Vignette Panel */
      .vignette-panel {
        padding: 16px 24px;
        background-color: var(--bg-surface-alt);
        border-bottom: 1px solid var(--border);
      }
      .section-label {
        font-size: 0.75rem;
        text-transform: uppercase;
        letter-spacing: 0.05em;
        font-weight: 600;
        color: var(--muted);
        margin-bottom: 8px;
      }
      .vignette-content {
        font-size: var(--vignette-font-size, 0.95rem);
        line-height: 1.6;
        color: var(--text-secondary);
        white-space: pre-wrap;
      }
      .vignette-zoom-controls {
        display: inline-flex;
        align-items: center;
        gap: 6px;
      }
      .zoom-btn {
        background: none;
        border: 1px solid var(--border);
        border-radius: 4px;
        width: 26px;
        height: 24px;
        display: inline-flex;
        align-items: center;
        justify-content: center;
        font-size: 0.75rem;
        font-weight: bold;
        color: var(--text-secondary);
        cursor: pointer;
        transition: all 0.2s ease;
        padding: 0;
      }
      .zoom-btn:hover {
        background-color: var(--bg-surface-alt);
        color: var(--brand);
        border-color: var(--brand);
      }
      .session-disclaimer {
        text-align: left;
        font-size: 0.75rem;
        color: var(--muted);
        line-height: 1.5;
        margin-top: 16px;
        margin-bottom: 24px;
        max-width: 100%;
        padding: 16px 24px 0 24px;
        border-top: 1px solid var(--border);
      }

      /* Question & Answer Sections */
      .question-section,
      .answer-section {
        padding: 40px 24px 32px 24px;
        display: flex;
        flex-direction: column;
        align-items: center;
        text-align: center;
      }
      .question-text {
        font-size: calc(var(--vignette-font-size, 0.95rem) + 0.25rem);
        font-weight: 600;
        line-height: 1.65;
        color: var(--text);
        margin: 16px 0 24px 0;
        width: 100%;
        max-width: 600px;
        white-space: pre-wrap;
        text-align: center;
      }
      .answer-text {
        font-size: calc(var(--vignette-font-size, 0.95rem) + 0.25rem);
        font-weight: 700;
        line-height: 1.65;
        color: var(--text);
        margin: 16px 0 0 0;
        width: 100%;
        max-width: 600px;
        white-space: pre-wrap;
        text-align: center;
      }

      /* Show Answer Button & shortcut */
      .show-answer-wrapper {
        display: flex;
        justify-content: center;
        width: 100%;
        margin-top: 24px;
      }
      .show-answer-btn {
        height: 48px !important;
        padding: 0 32px !important;
        min-width: 140px;
        font-weight: 600 !important;
        border-radius: var(--radius-btn) !important;
        display: inline-flex;
        align-items: center;
        gap: 8px;
      }
      .shortcut-kbd {
        font-family: inherit;
        font-size: 0.75rem;
        background-color: rgba(0, 0, 0, 0.1);
        border-radius: 4px;
        padding: 2px 6px;
        margin-left: 4px;
        opacity: 0.8;
      }

      /* Divider separating states */
      .state-divider {
        margin: 4px 0;
        border: 0;
        border-top: 1px solid var(--border);
      }

      /* NBME Pearl Section */
      .pearl-section {
        padding: 16px 24px;
        border-top: 1px solid var(--border);
      }
      .pearl-content-box {
        padding: 16px;
        background-color: var(--bg-surface-alt);
        border-radius: var(--radius-sm);
        border: 1px solid var(--border);
        margin-top: 8px;
        text-align: left;
      }
      .pearl-text {
        font-size: 0.95rem;
        line-height: 1.6;
        color: var(--text-secondary);
        white-space: pre-wrap;
      }

      /* Rating & Action Section */
      .rating-section {
        padding: 24px 24px 32px 24px;
        border-top: 1px solid var(--border);
      }
            .learn-more-links {
        display: flex;
        flex-direction: column;
        align-items: center;
        text-align: center;
        gap: 10px;
        margin-bottom: 24px;
        color: var(--text-secondary);
        font-size: 0.95rem;
        font-weight: 500;
      }
      .learn-more-links__title {
        text-align: center;
        width: 100%;
      }
      .learn-more-links__list {
        width: 100%;
        display: flex;
        flex-direction: column;
        gap: 8px;
        align-items: stretch;
      }
      .learn-more-link-item {
        display: flex;
        align-items: center;
        justify-content: center;
        gap: 8px;
        padding: 10px 14px;
        border-radius: var(--radius-sm);
        border: 1px solid var(--border);
        background-color: var(--bg-surface-alt);
        color: var(--text-secondary);
        text-decoration: none;
        transition: all var(--duration-fast) var(--ease-standard);
        width: 100%;
        text-align: center;
      }
      .learn-more-link-item:hover {
        color: var(--text);
        border-color: var(--brand);
        transform: translateY(-1px);
      }
      .learn-more-link-item__text {
        overflow-wrap: anywhere;
        text-align: center;
      }
      .learn-more-favicon {
        width: 20px;
        height: 20px;
        border-radius: 4px;
        object-fit: cover;
        flex-shrink: 0;
      }

      /* Rating Buttons Row */
      .rating-row {
        display: flex;
        gap: 8px;
        width: 100%;
        margin-top: 12px;
      }
      .rating-btn {
        flex: 1;
        min-height: 60px;
        display: flex;
        flex-direction: column;
        align-items: center;
        justify-content: center;
        gap: 6px;
        border-radius: var(--radius-btn) !important;
        cursor: pointer;
        padding: 8px 12px;
        transition: all var(--duration-fast) var(--ease-standard);
      }
      .rating-btn-label {
        font-size: 0.95rem;
        font-weight: 600;
        color: var(--text);
      }
      .rating-btn-kbd {
        display: inline-flex;
        align-items: center;
        justify-content: center;
        background-color: var(--bg-surface-alt);
        border: 1px solid var(--border);
        border-radius: 4px;
        min-width: 20px;
        height: 20px;
        padding: 0 6px;
        font-size: 0.75rem;
        font-weight: 600;
        color: var(--muted);
        line-height: 1;
      }
      .rating-btn--reviewed {
        background-color: rgba(16, 185, 129, 0.06) !important;
        border: 1px solid rgba(16, 185, 129, 0.18) !important;
      }
      .rating-btn--reviewed:hover {
        background-color: rgba(16, 185, 129, 0.14) !important;
        border-color: rgba(16, 185, 129, 0.35) !important;
        transform: translateY(-1px);
      }
      .rating-btn--flag {
        background-color: rgba(245, 158, 11, 0.06) !important;
        border: 1px solid rgba(245, 158, 11, 0.18) !important;
      }
      .rating-btn--flag:hover {
        background-color: rgba(245, 158, 11, 0.14) !important;
        border-color: rgba(245, 158, 11, 0.35) !important;
        transform: translateY(-1px);
      }

      /* Show Question link */
      .show-question-toggle {
        font-size: 0.85rem;
        color: var(--muted);
        cursor: pointer;
        font-weight: 500;
        user-select: none;
        transition: color var(--duration-fast) var(--ease-standard);
      }
      .show-question-toggle:hover {
        color: var(--text-secondary);
        text-decoration: underline;
      }

      /* Completion State Card styles */
      .completion-card {
        max-width: 720px;
        width: 100%;
        margin: 32px auto;
      }
      .completion-body {
        display: flex;
        flex-direction: column;
        gap: 16px;
        align-items: center;
        padding: 40px 24px;
      }

      /* Responsive Rules */
      @media (max-width: 768px) {
        .session-container {
          padding-left: 12px;
          padding-right: 12px;
        }
        .card-study {
          margin-top: 16px;
          margin-bottom: 16px;
        }
        .card-meta-bar,
        .vignette-panel,
        .question-section,
        .answer-section,
        .pearl-section,
        .rating-section {
          padding-left: 16px !important;
          padding-right: 16px !important;
        }
        .question-text,
        .answer-text {
          font-size: 1.05rem !important;
        }
        .rating-row {
          flex-direction: column !important;
          gap: 8px !important;
        }
        .rating-btn {
          width: 100% !important;
          min-height: 52px !important;
          flex: none !important;
        }
        .learn-more-links {
          width: 100% !important;
          text-align: center !important;
          justify-content: center !important;
        }
        .card-meta-bar {
          flex-wrap: wrap !important;
          gap: 8px;
        }
      }

      .fc-limit-selector-container {
        display: flex;
        align-items: center;
        gap: 8px;
        margin-right: 4px;
      }
      .fc-limit-selector-container .fc-limit-input {
        width: 80px;
        text-align: center;
        padding: 0 8px;
      }