/* ==========================================================================
   5. Bookshelf, Continuous Reader, Typography Controls & Wikipedia
   ========================================================================== */

/* ==========================================================================
   Stage 5: Interactive Reader & Bookshelf Styles
   ========================================================================== */

.reader-view {
    max-width: 1100px;
    margin: 0 auto;
    padding: 24px 20px 80px;
}

.bookshelf-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 16px;
    margin-bottom: 28px;
    padding-bottom: 20px;
    border-bottom: 1px solid var(--border-color);
}

.bookshelf-title-wrap h2 {
    font-size: 24px;
    font-weight: 700;
    color: var(--text-main);
    display: flex;
    align-items: center;
    gap: 8px;
}

.bookshelf-title-wrap .subtitle {
    font-size: 14px;
    color: var(--text-muted);
    margin-top: 4px;
}

.bookshelf-actions {
    display: flex;
    align-items: center;
    gap: 12px;
}

.file-upload-label {
    cursor: pointer;
    display: inline-flex;
    align-items: center;
    gap: 6px;
}

.bookshelf-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 20px;
}

.book-card {
    background-color: var(--bg-surface);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 20px;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    transition: var(--transition);
    position: relative;
    box-shadow: var(--shadow-sm);
}

.book-card:hover {
    border-color: var(--border-focus);
    box-shadow: var(--shadow-md);
    transform: translateY(-2px);
}

.book-card-top {
    display: flex;
    align-items: flex-start;
    gap: 14px;
    margin-bottom: 14px;
}

.book-cover-icon {
    font-size: 32px;
    background: var(--bg-input);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    width: 52px;
    height: 64px;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.book-card-info {
    flex: 1;
    min-width: 0;
}

.book-card-title {
    font-size: 16px;
    font-weight: 700;
    color: var(--text-main);
    margin-bottom: 4px;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.book-card-author {
    font-size: 13px;
    color: var(--text-muted);
    margin-bottom: 8px;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.book-card-badges {
    display: flex;
    align-items: center;
    gap: 8px;
}

.badge-format {
    text-transform: uppercase;
    font-size: 10px;
    font-weight: 700;
    padding: 2px 6px;
    border-radius: var(--radius-sm);
    background: var(--tag-bg);
    color: var(--tag-text);
}

.badge-words {
    font-size: 12px;
    color: var(--text-dim);
}

.book-progress-wrap {
    margin: 14px 0 16px;
}

.book-progress-labels {
    display: flex;
    justify-content: space-between;
    font-size: 12px;
    color: var(--text-dim);
    margin-bottom: 6px;
}

.book-progress-bar-bg {
    width: 100%;
    height: 6px;
    background-color: var(--bg-input);
    border-radius: var(--radius-full);
    overflow: hidden;
}

.book-progress-bar-fill {
    height: 100%;
    background-color: var(--primary);
    border-radius: var(--radius-full);
    transition: width 0.3s ease;
}

.book-card-actions {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 8px;
    padding-top: 12px;
    border-top: 1px solid var(--border-color);
}

/* Bookshelf Divider between General Books & RFC Specifications */
.bookshelf-divider {
    margin: 48px 0 36px;
    border: 0;
    height: 1px;
    background: linear-gradient(90deg, transparent, var(--border-color) 15%, var(--border-color) 85%, transparent);
}

/* RFC Specifications Section */
.rfc-section {
    margin-top: 8px;
}

.rfc-header {
    margin-bottom: 20px;
}

.rfc-title-row {
    display: flex;
    align-items: center;
    gap: 14px;
}

.rfc-icon-badge {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 44px;
    height: 44px;
    font-size: 24px;
    background: rgba(14, 165, 233, 0.12);
    border: 1px solid rgba(14, 165, 233, 0.28);
    border-radius: var(--radius-md);
    flex-shrink: 0;
}

.rfc-heading {
    font-size: 20px;
    font-weight: 700;
    color: var(--text-main);
    margin: 0;
}

.rfc-fetch-box {
    background: var(--bg-surface);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 20px 24px;
    margin-bottom: 24px;
    box-shadow: var(--shadow-sm);
}

.rfc-fetch-form {
    margin-bottom: 16px;
}

.rfc-input-wrap {
    display: flex;
    align-items: stretch;
    gap: 10px;
}

.rfc-input-prefix {
    display: inline-flex;
    align-items: center;
    padding: 0 14px;
    font-weight: 700;
    font-size: 13px;
    letter-spacing: 0.05em;
    color: #38bdf8;
    background: rgba(56, 189, 248, 0.12);
    border: 1px solid rgba(56, 189, 248, 0.25);
    border-radius: var(--radius-md);
    user-select: none;
}

.rfc-input {
    flex: 1;
    min-width: 0;
}

.rfc-fetch-btn {
    white-space: nowrap;
    padding: 0 20px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font-weight: 600;
}

.rfc-fetch-status {
    margin-top: 10px;
    padding: 8px 14px;
    font-size: 13px;
    border-radius: var(--radius-md);
    transition: all 0.2s ease;
}

.rfc-status-loading {
    background: rgba(14, 165, 233, 0.1);
    color: #38bdf8;
    border: 1px solid rgba(14, 165, 233, 0.25);
}

.rfc-status-success {
    background: rgba(34, 197, 94, 0.12);
    color: #4ade80;
    border: 1px solid rgba(34, 197, 94, 0.25);
}

.rfc-status-error {
    background: rgba(239, 68, 68, 0.12);
    color: #f87171;
    border: 1px solid rgba(239, 68, 68, 0.25);
}

.rfc-presets-wrap {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.rfc-presets-label {
    font-size: 12px;
    text-transform: uppercase;
    font-weight: 600;
    letter-spacing: 0.05em;
    color: var(--text-dim);
}

.rfc-presets-list {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

.rfc-preset-chip {
    background: var(--bg-input);
    color: var(--text-main);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-full);
    padding: 6px 14px;
    font-size: 12.5px;
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition);
    user-select: none;
    display: inline-flex;
    align-items: center;
    gap: 5px;
}

.rfc-preset-chip:hover {
    background: rgba(14, 165, 233, 0.15);
    border-color: #38bdf8;
    color: #38bdf8;
    transform: translateY(-1px);
}

.rfc-empty-state {
    padding: 36px 20px;
    background: var(--bg-surface);
    border: 1px dashed var(--border-color);
    border-radius: var(--radius-lg);
    margin-bottom: 24px;
}

.rfc-card {
    border-color: rgba(56, 189, 248, 0.2);
}

.rfc-card:hover {
    border-color: rgba(56, 189, 248, 0.5);
    box-shadow: 0 8px 24px rgba(14, 165, 233, 0.12);
}

.rfc-cover-icon {
    background: rgba(14, 165, 233, 0.1);
    border-color: rgba(14, 165, 233, 0.25);
}

.badge-rfc {
    background: rgba(14, 165, 233, 0.2);
    color: #38bdf8;
    border: 1px solid rgba(14, 165, 233, 0.35);
}

.rfc-progress-fill {
    background: linear-gradient(90deg, #0284c7, #38bdf8);
}

@media (max-width: 640px) {
    .rfc-input-wrap {
        flex-direction: column;
    }
    .rfc-input-prefix {
        display: none;
    }
    .rfc-fetch-btn {
        width: 100%;
        padding: 10px 16px;
    }
}

/* ==========================================================================
   Wikipedia Articles Section & Settings Modal
   ========================================================================== */

.wiki-section {
    margin-top: 8px;
}

.wiki-header {
    margin-bottom: 20px;
}

.wiki-title-row {
    display: flex;
    align-items: center;
    gap: 14px;
}

.wiki-icon-badge {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 44px;
    height: 44px;
    font-size: 24px;
    background: rgba(168, 85, 247, 0.12);
    border: 1px solid rgba(168, 85, 247, 0.28);
    border-radius: var(--radius-md);
    flex-shrink: 0;
}

.wiki-heading {
    font-size: 20px;
    font-weight: 700;
    color: var(--text-main);
    margin: 0;
}

.wiki-action-box {
    background: var(--bg-surface);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 20px 24px;
    margin-bottom: 24px;
    box-shadow: var(--shadow-sm);
}

.wiki-primary-actions {
    display: flex;
    align-items: center;
    gap: 12px;
    flex-wrap: wrap;
    margin-bottom: 14px;
}

.wiki-read-btn {
    padding: 10px 24px;
    font-weight: 700;
    font-size: 15px;
    background: linear-gradient(135deg, #6366f1, #8b5cf6);
    border: none;
    box-shadow: 0 4px 14px rgba(99, 102, 241, 0.35);
    transition: all 0.2s ease;
}

.wiki-read-btn:hover {
    background: linear-gradient(135deg, #4f46e5, #7c3aed);
    transform: translateY(-1px);
    box-shadow: 0 6px 18px rgba(99, 102, 241, 0.45);
}

.wiki-settings-btn {
    padding: 10px 18px;
    font-weight: 600;
    border-color: rgba(168, 85, 247, 0.35);
    color: var(--text-main);
}

.wiki-settings-btn:hover {
    background: rgba(168, 85, 247, 0.12);
    border-color: #a855f7;
    color: #c084fc;
}

.wiki-badges-row {
    display: flex;
    align-items: center;
    gap: 8px;
    flex-wrap: wrap;
    font-size: 13px;
}

.wiki-badges-label {
    color: var(--text-dim);
    font-size: 12px;
    text-transform: uppercase;
    font-weight: 600;
    letter-spacing: 0.05em;
    margin-right: 4px;
}

.wiki-badge-chip {
    background: rgba(168, 85, 247, 0.12);
    color: #c084fc;
    border: 1px solid rgba(168, 85, 247, 0.28);
    border-radius: var(--radius-full);
    padding: 4px 12px;
    font-weight: 500;
    font-size: 12px;
    display: inline-flex;
    align-items: center;
    gap: 4px;
}

.wiki-fetch-status {
    margin-top: 14px;
    padding: 10px 16px;
    font-size: 13.5px;
    border-radius: var(--radius-md);
    transition: all 0.2s ease;
}

.wiki-status-loading {
    background: rgba(99, 102, 241, 0.12);
    color: #818cf8;
    border: 1px solid rgba(99, 102, 241, 0.3);
}

.wiki-status-success {
    background: rgba(34, 197, 94, 0.12);
    color: #4ade80;
    border: 1px solid rgba(34, 197, 94, 0.25);
}

.wiki-status-error {
    background: rgba(239, 68, 68, 0.12);
    color: #f87171;
    border: 1px solid rgba(239, 68, 68, 0.25);
}

.wiki-empty-state {
    padding: 36px 20px;
    background: var(--bg-surface);
    border: 1px dashed var(--border-color);
    border-radius: var(--radius-lg);
    margin-bottom: 24px;
}

/* Card styling for Wikipedia and thumbnails */
.wiki-card {
    border-color: rgba(168, 85, 247, 0.22);
}

.wiki-card:hover {
    border-color: rgba(168, 85, 247, 0.55);
    box-shadow: 0 8px 24px rgba(168, 85, 247, 0.15);
}

.wiki-cover-icon {
    background: rgba(168, 85, 247, 0.12);
    border-color: rgba(168, 85, 247, 0.3);
    color: #c084fc;
}

.badge-wiki {
    background: rgba(168, 85, 247, 0.18);
    color: #c084fc;
    border: 1px solid rgba(168, 85, 247, 0.35);
}

.wiki-progress-fill {
    background: linear-gradient(90deg, #7c3aed, #a855f7);
}

.book-cover-img-wrap {
    width: 52px;
    height: 64px;
    border-radius: var(--radius-sm);
    overflow: hidden;
    flex-shrink: 0;
    background: rgba(0, 0, 0, 0.2);
    border: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    justify-content: center;
}

.book-cover-img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: block;
}

.badge-time {
    display: inline-flex;
    align-items: center;
    gap: 3px;
    background: rgba(255, 255, 255, 0.06);
    color: var(--text-dim);
    font-size: 11px;
    font-weight: 500;
    padding: 2px 7px;
    border-radius: var(--radius-sm);
    border: 1px solid rgba(255, 255, 255, 0.08);
}

/* Wikipedia Settings Modal */
.wiki-modal-window {
    max-width: 620px;
    width: 95%;
}

.wiki-modal-body {
    display: flex;
    flex-direction: column;
    gap: 22px;
}

.wiki-setting-group {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.wiki-group-label {
    font-size: 13.5px;
    font-weight: 700;
    color: var(--text-main);
    letter-spacing: 0.02em;
}

.wiki-radio-cards {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 12px;
}

.wiki-radio-card {
    display: flex;
    align-items: flex-start;
    gap: 12px;
    padding: 14px 16px;
    background: var(--bg-input);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all 0.2s ease;
    user-select: none;
}

.wiki-radio-card:hover {
    border-color: rgba(168, 85, 247, 0.4);
    background: rgba(168, 85, 247, 0.04);
}

.wiki-radio-card:has(input:checked) {
    border-color: #a855f7;
    background: rgba(168, 85, 247, 0.1);
    box-shadow: 0 0 0 1px #a855f7;
}

.wiki-radio-card input[type="radio"] {
    margin-top: 3px;
    accent-color: #a855f7;
}

.wiki-radio-card-content {
    display: flex;
    flex-direction: column;
    gap: 5px;
}

.wiki-card-title-row {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 8px;
}

.wiki-card-desc {
    font-size: 12px;
    color: var(--text-dim);
    line-height: 1.45;
    margin: 0;
}

.badge-level-pill {
    font-size: 10.5px;
    font-weight: 700;
    padding: 1px 7px;
    border-radius: var(--radius-full);
    text-transform: uppercase;
    letter-spacing: 0.04em;
}

.badge-level-a2 {
    background: rgba(34, 197, 94, 0.2);
    color: #4ade80;
    border: 1px solid rgba(34, 197, 94, 0.35);
}

.badge-level-b2 {
    background: rgba(59, 130, 246, 0.2);
    color: #60a5fa;
    border: 1px solid rgba(59, 130, 246, 0.35);
}

.wiki-time-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(130px, 1fr));
    gap: 8px;
}

.wiki-time-pill {
    display: flex;
    align-items: center;
    position: relative;
    cursor: pointer;
    user-select: none;
}

.wiki-time-pill input[type="radio"] {
    position: absolute;
    opacity: 0;
    pointer-events: none;
}

.wiki-pill-text {
    width: 100%;
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    padding: 10px 8px;
    background: var(--bg-input);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    font-size: 13px;
    font-weight: 600;
    color: var(--text-main);
    transition: all 0.2s ease;
}

.wiki-pill-text small {
    font-size: 11px;
    font-weight: normal;
    margin-top: 2px;
}

.wiki-time-pill:hover .wiki-pill-text {
    border-color: rgba(168, 85, 247, 0.4);
}

.wiki-time-pill input[type="radio"]:checked + .wiki-pill-text {
    border-color: #a855f7;
    background: rgba(168, 85, 247, 0.12);
    color: #c084fc;
    box-shadow: 0 0 0 1px #a855f7;
}

.wiki-select {
    width: 100%;
    padding: 10px 14px;
    font-size: 14px;
}

.wiki-direct-import-group {
    border-top: 1px dashed var(--border-color);
    padding-top: 18px;
}

.wiki-custom-input-wrap {
    display: flex;
    align-items: center;
    gap: 10px;
}

.wiki-custom-input {
    flex: 1;
    min-width: 0;
}

.wiki-custom-fetch-btn {
    white-space: nowrap;
    padding: 0 18px;
    font-weight: 600;
}

@media (max-width: 640px) {
    .wiki-radio-cards {
        grid-template-columns: 1fr;
    }
    .wiki-custom-input-wrap {
        flex-direction: column;
    }
    .wiki-custom-fetch-btn {
        width: 100%;
        padding: 10px 16px;
    }
}

/* Reader Interface */
.reader-interface {
    background-color: var(--bg-surface);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
}

.reader-toolbar {
    position: sticky;
    top: var(--navbar-height, 60px);
    z-index: 1000;
    background-color: var(--bg-surface);
    border-top-left-radius: var(--radius-lg);
    border-top-right-radius: var(--radius-lg);
    border-bottom: 1px solid var(--border-color);
    padding: 12px 18px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 12px;
    box-shadow: 0 4px 14px rgba(0, 0, 0, 0.15);
}

.reader-toolbar-left {
    display: flex;
    align-items: center;
    gap: 14px;
}

.reader-meta {
    display: flex;
    flex-direction: column;
}

.reader-title {
    font-size: 16px;
    font-weight: 700;
    color: var(--text-main);
    line-height: 1.2;
}

.reader-author {
    font-size: 12px;
    color: var(--text-muted);
}

.reader-toolbar-center {
    display: flex;
    align-items: center;
    gap: 8px;
}

.reader-select {
    padding: 6px 12px;
    border-radius: var(--radius-sm);
    background-color: var(--bg-input);
    color: var(--text-main);
    border: 1px solid var(--border-color);
    font-size: 13px;
    outline: none;
    max-width: 240px;
}

.reader-progress-badge {
    font-size: 11px;
    font-weight: 700;
    font-variant-numeric: tabular-nums;
    color: var(--primary);
    background: var(--primary-dim);
    border: 1px solid rgba(56, 189, 248, 0.35);
    padding: 3px 8px;
    border-radius: var(--radius-full);
    min-width: 40px;
    text-align: center;
    display: inline-block;
    user-select: none;
    line-height: 1.2;
}

.reader-chapter-progress-bar {
    position: absolute;
    left: 0;
    right: 0;
    bottom: -1px;
    height: 3px;
    background-color: rgba(255, 255, 255, 0.08);
    overflow: hidden;
    pointer-events: none;
}

.reader-chapter-progress-fill {
    height: 100%;
    width: 0%;
    background: linear-gradient(90deg, #0284c7, #38bdf8);
    box-shadow: 0 0 8px rgba(56, 189, 248, 0.5);
    transition: width 0.12s cubic-bezier(0.16, 1, 0.3, 1);
}

.reader-toolbar-right {
    display: flex;
    align-items: center;
    gap: 10px;
}

.font-controls {
    display: flex;
    align-items: center;
    gap: 4px;
}

.reader-scroll-area {
    --reader-font-size: 18px;
    --reader-line-height: 1.65;
    --reader-font-family: 'Literata', 'Merriweather', 'Georgia', 'Cambria', serif;
    --reader-max-width: 760px;
    --reader-padding-h: 24px;
    --reader-text-align: left;
    --reader-bg: var(--bg-surface);
    --reader-text: var(--text-main);

    background-color: var(--reader-bg);
    min-height: 60vh;
    padding: 0;
    transition: background-color 0.2s ease, color 0.2s ease;
}

.reader-content-body {
    max-width: var(--reader-max-width);
    margin: 0 auto;
    padding: 32px var(--reader-padding-h) 80px;
    font-family: var(--reader-font-family);
    font-size: var(--reader-font-size);
    line-height: var(--reader-line-height);
    text-align: var(--reader-text-align);
    color: var(--reader-text);
    word-break: break-word;
    user-select: text;
    transition: font-size 0.15s ease, line-height 0.15s ease, max-width 0.2s ease, padding 0.2s ease;
}

/* Reader Appearance Themes */
.reader-scroll-area.reader-theme-sepia {
    --reader-bg: #fbf0d9;
    --reader-text: #433422;
}
.reader-scroll-area.reader-theme-sepia .reader-word:hover {
    background-color: rgba(217, 119, 6, 0.25);
    color: #92400e;
}
.reader-scroll-area.reader-theme-sepia blockquote {
    background-color: #f4e4c1;
    border-color: #d6bc97;
    color: #5f4b32;
}
.reader-scroll-area.reader-theme-sepia .reader-inline-code,
.reader-scroll-area.reader-theme-sepia .reader-code-wrap pre {
    background-color: #efe0bc;
    color: #433422;
    border-color: #dec89f;
}
.reader-scroll-area.reader-theme-sepia .reader-table th,
.reader-scroll-area.reader-theme-sepia .reader-table td {
    border-color: #dec89f;
}

.reader-scroll-area.reader-theme-light {
    --reader-bg: #ffffff;
    --reader-text: #1e293b;
}
.reader-scroll-area.reader-theme-light blockquote {
    background-color: #f8fafc;
    border-color: #cbd5e1;
    color: #334155;
}
.reader-scroll-area.reader-theme-light .reader-inline-code,
.reader-scroll-area.reader-theme-light .reader-code-wrap pre {
    background-color: #f1f5f9;
    color: #0f172a;
    border-color: #e2e8f0;
}
.reader-scroll-area.reader-theme-light .reader-word:hover {
    background-color: rgba(2, 132, 199, 0.15);
    color: #0284c7;
}

.reader-scroll-area.reader-theme-oled {
    --reader-bg: #000000;
    --reader-text: #d8e2ec;
}
.reader-scroll-area.reader-theme-oled blockquote {
    background-color: #0a0e17;
    border-color: #1e293b;
}
.reader-scroll-area.reader-theme-oled .reader-inline-code,
.reader-scroll-area.reader-theme-oled .reader-code-wrap pre {
    background-color: #0a0e17;
    border-color: #1e293b;
}

.reader-scroll-area.reader-theme-dark {
    --reader-bg: var(--bg-surface);
    --reader-text: var(--text-main);
}

/* Reader Font Families */
.reader-scroll-area.reader-font-sans {
    --reader-font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
}
.reader-scroll-area.reader-font-serif {
    --reader-font-family: 'Literata', 'Merriweather', 'Georgia', 'Cambria', 'Times New Roman', serif;
}
.reader-scroll-area.reader-font-mono {
    --reader-font-family: 'JetBrains Mono', 'Fira Code', 'Menlo', 'Consolas', monospace;
}

/* Reader Margin & Width Variants */
.reader-scroll-area.reader-margins-narrow {
    --reader-max-width: 940px;
    --reader-padding-h: 12px;
}
.reader-scroll-area.reader-margins-normal {
    --reader-max-width: 760px;
    --reader-padding-h: 24px;
}
.reader-scroll-area.reader-margins-wide {
    --reader-max-width: 600px;
    --reader-padding-h: 36px;
}

/* Reader Text Alignment */
.reader-scroll-area.reader-align-left {
    --reader-text-align: left;
}
.reader-scroll-area.reader-align-justify {
    --reader-text-align: justify;
    hyphens: auto;
}

/* Reader Appearance Settings Panel / Sheet */
.reader-settings-panel {
    position: fixed;
    top: 64px;
    right: 28px;
    width: 330px;
    max-width: calc(100vw - 32px);
    max-height: calc(100vh - 80px);
    display: flex;
    flex-direction: column;
    background-color: var(--bg-surface);
    border: 1px solid var(--border-focus);
    border-radius: var(--radius-lg);
    box-shadow: 0 16px 36px rgba(0, 0, 0, 0.45);
    z-index: 10006;
    padding: 16px;
    animation: fadeIn 0.15s ease-out;
}

.reader-settings-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-shrink: 0;
    margin-bottom: 12px;
    padding-bottom: 8px;
    border-bottom: 1px solid var(--border-color);
}

.reader-settings-header h4 {
    font-size: 15px;
    font-weight: 700;
    color: var(--text-main);
}

.reader-settings-body {
    display: flex;
    flex-direction: column;
    gap: 12px;
    overflow-y: auto;
    padding-right: 4px;
    scrollbar-width: thin;
    scrollbar-color: var(--border-focus) transparent;
}

.reader-settings-body::-webkit-scrollbar {
    width: 6px;
}

.reader-settings-body::-webkit-scrollbar-thumb {
    background-color: var(--border-focus);
    border-radius: 3px;
}

.setting-row {
    display: flex;
    flex-direction: column;
    gap: 6px;
}

.setting-row-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 8px;
    align-items: flex-end;
}

.setting-row-grid .seg-btn {
    padding: 6px 4px;
    font-size: 11.5px;
}

.setting-label {
    font-size: 11px;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    color: var(--text-muted);
}

.setting-segmented-control {
    display: flex;
    background-color: var(--bg-input);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    padding: 2px;
    gap: 2px;
}

.seg-btn {
    flex: 1;
    padding: 6px 8px;
    font-size: 12px;
    font-weight: 600;
    background: transparent;
    border: none;
    border-radius: 4px;
    color: var(--text-muted);
    cursor: pointer;
    transition: var(--transition);
    text-align: center;
}

.seg-btn:hover {
    color: var(--text-main);
}

.seg-btn.active {
    background-color: var(--primary);
    color: #0f172a;
}

.setting-stepper {
    display: flex;
    align-items: center;
    justify-content: space-between;
    background-color: var(--bg-input);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    padding: 4px 6px;
}

.step-btn {
    background: var(--bg-surface-hover);
    border: 1px solid var(--border-color);
    border-radius: 4px;
    color: var(--text-main);
    font-size: 13px;
    font-weight: 700;
    width: 38px;
    height: 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
}

.step-val {
    font-size: 14px;
    font-weight: 700;
    color: var(--primary);
}

.theme-palette {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 6px;
}

.theme-chip {
    padding: 7px 10px;
    font-size: 12px;
    font-weight: 600;
    border-radius: var(--radius-sm);
    border: 2px solid transparent;
    cursor: pointer;
    text-align: center;
    transition: var(--transition);
}

.theme-chip-dark { background: #1e293b; color: #f8fafc; border-color: #334155; }
.theme-chip-sepia { background: #fbf0d9; color: #433422; border-color: #d6bc97; }
.theme-chip-light { background: #ffffff; color: #0f172a; border-color: #cbd5e1; }
.theme-chip-oled { background: #000000; color: #e2e8f0; border-color: #334155; }

.theme-chip.active {
    border-color: var(--primary) !important;
    box-shadow: 0 0 0 2px var(--primary-dim);
}

.reader-settings-btn {
    display: inline-flex;
    align-items: center;
    gap: 4px;
}

.reader-content-body h1,
.reader-content-body h2,
.reader-content-body h3,
.reader-content-body h4,
.reader-content-body h5,
.reader-content-body h6 {
    font-family: var(--font-family);
    margin: 28px 0 16px;
    color: var(--text-main);
    text-indent: 0;
}

.reader-content-body h4 { font-size: 1.15em; }
.reader-content-body h5 { font-size: 1.05em; }

.reader-content-body p {
    margin-bottom: 20px;
    text-indent: 1.2em;
}

/* Fenced Code Block */
.reader-code-block {
    margin: 24px 0;
    border-radius: var(--radius-md);
    background: #141820;
    border: 1px solid var(--border-color);
    overflow: hidden;
    box-shadow: 0 4px 14px rgba(0, 0, 0, 0.3);
}

.reader-code-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 8px 14px;
    background: rgba(255, 255, 255, 0.04);
    border-bottom: 1px solid var(--border-color);
    font-family: monospace;
    font-size: 12px;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.reader-code-lang {
    font-weight: 600;
}

.reader-copy-code-btn {
    background: transparent;
    border: 1px solid var(--border-color);
    color: var(--text-muted);
    border-radius: 4px;
    padding: 3px 8px;
    font-size: 11px;
    cursor: pointer;
    transition: all 0.15s ease;
    display: inline-flex;
    align-items: center;
    gap: 4px;
}

.reader-copy-code-btn:hover {
    background: rgba(255, 255, 255, 0.08);
    color: var(--text-main);
    border-color: var(--primary);
}

.reader-content-body pre {
    margin: 0;
    padding: 16px;
    overflow-x: auto;
    background: transparent;
    border: none;
    border-radius: 0;
    font-family: 'JetBrains Mono', 'Fira Code', 'Consolas', monospace;
    font-size: 14.5px;
    line-height: 1.6;
    text-indent: 0 !important;
    white-space: pre;
    tab-size: 4;
}

.reader-content-body pre code {
    font-family: inherit;
    font-size: inherit;
    color: #e6edf3;
    background: transparent;
    padding: 0;
    border: none;
    white-space: pre;
    display: block;
    text-indent: 0;
}

/* Inline Code Badge */
.reader-inline-code {
    font-family: 'JetBrains Mono', 'Consolas', monospace;
    font-size: 0.88em;
    background: rgba(255, 255, 255, 0.08);
    color: var(--primary);
    padding: 2px 6px;
    border-radius: 4px;
    border: 1px solid rgba(255, 255, 255, 0.12);
    white-space: pre-wrap;
    word-break: break-all;
}

/* Blockquote */
.reader-content-body blockquote {
    margin: 20px 0;
    padding: 12px 20px;
    border-left: 4px solid var(--primary);
    background: rgba(56, 189, 248, 0.06);
    border-radius: 0 var(--radius-md) var(--radius-md) 0;
    font-style: italic;
    color: var(--text-main);
    text-indent: 0;
}

.reader-content-body blockquote p {
    margin: 0;
    text-indent: 0;
}

/* Lists */
.reader-content-body ul,
.reader-content-body ol {
    margin: 16px 0 20px 24px;
    padding-left: 12px;
    text-indent: 0;
}

.reader-content-body li {
    margin-bottom: 8px;
    line-height: 1.7;
    text-indent: 0;
}

.reader-content-body hr {
    border: 0;
    height: 1px;
    background: var(--border-color);
    margin: 32px 0;
}

/* Headings */
.reader-content-body h1,
.reader-content-body h2,
.reader-content-body h3,
.reader-content-body h4,
.reader-content-body h5,
.reader-content-body h6 {
    color: var(--text-main);
    font-weight: 700;
    line-height: 1.35;
    margin: 32px 0 16px;
    text-indent: 0 !important;
}

.reader-content-body h1 {
    font-size: 28px;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 10px;
}

.reader-content-body h2 {
    font-size: 23px;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 8px;
}

.reader-content-body h3 {
    font-size: 19px;
}

.reader-content-body h4 {
    font-size: 17px;
}

/* Markdown Tables */
.reader-table-wrap {
    overflow-x: auto;
    margin: 24px 0;
    border-radius: var(--radius-md);
    border: 1px solid var(--border-color);
    background: var(--bg-surface);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
}

.reader-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 14.5px;
    line-height: 1.6;
    text-indent: 0 !important;
}

.reader-table th,
.reader-table td {
    padding: 10px 16px;
    border-bottom: 1px solid var(--border-color);
    border-right: 1px solid var(--border-color);
    vertical-align: top;
    text-indent: 0 !important;
}

.reader-table th:last-child,
.reader-table td:last-child {
    border-right: none;
}

.reader-table tr:last-child td {
    border-bottom: none;
}

.reader-table th {
    background-color: rgba(255, 255, 255, 0.05);
    font-weight: 700;
    color: var(--text-main);
    text-align: left;
}

.reader-table tbody tr:hover {
    background-color: rgba(255, 255, 255, 0.02);
}

/* Links & Images */
.reader-link {
    color: var(--primary);
    text-decoration: underline;
    text-decoration-thickness: 1px;
    text-underline-offset: 3px;
    transition: color 0.15s ease;
}

.reader-link:hover {
    color: var(--primary-hover);
}

.reader-img {
    max-width: 100%;
    height: auto;
    border-radius: var(--radius-md);
    margin: 8px 0;
    vertical-align: middle;
}

.reader-content-body p img {
    margin: 4px 6px;
    display: inline-block;
    vertical-align: middle;
}

/* Figures and Media (Images, Diagrams, Animated GIFs, SVGs) */
.reader-figure {
    margin: 28px auto;
    padding: 14px;
    background: var(--bg-surface);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.15);
    display: flex;
    flex-direction: column;
    align-items: center;
    max-width: 95%;
    box-sizing: border-box;
}

.reader-figure-img {
    max-width: 100%;
    max-height: 480px;
    width: auto;
    height: auto;
    border-radius: var(--radius-md);
    object-fit: contain;
    display: block;
}

.reader-figcaption {
    margin-top: 12px;
    padding-top: 10px;
    border-top: 1px solid rgba(255, 255, 255, 0.08);
    font-size: 13.5px;
    line-height: 1.55;
    color: var(--text-dim);
    text-align: center;
    max-width: 90%;
    font-style: italic;
    user-select: text;
}

.reader-figcaption .reader-word {
    font-style: normal;
}

.reader-content-body p[style*="text-align: center"],
.reader-content-body p.text-center {
    text-indent: 0 !important;
}

.reader-content-body strong,
.reader-content-body b {
    font-weight: 700;
    color: var(--text-main);
}

.reader-content-body em,
.reader-content-body i {
    font-style: italic;
}

.reader-content-body sub,
.reader-content-body sup {
    font-size: 0.8em;
    line-height: 0;
    position: relative;
    vertical-align: baseline;
}
.reader-content-body sub { bottom: -0.25em; }
.reader-content-body sup { top: -0.5em; }

/* Interactive Words */
.reader-word {
    cursor: pointer;
    border-radius: 3px;
    transition: background-color 0.12s ease, color 0.12s ease;
    padding: 1px 2px;
}

.reader-word:hover {
    background-color: var(--primary-dim);
    color: var(--primary);
}

.reader-word.status-mastered.highlight-enabled {
    border-bottom: 2px dotted rgba(16, 185, 129, 0.5);
}

.reader-word.status-learning.highlight-enabled {
    border-bottom: 2px dotted rgba(56, 189, 248, 0.5);
}

/* Click-to-Translate Popup */
.reader-word-popup {
    position: fixed;
    z-index: 10005;
    background-color: var(--bg-surface);
    border: 1px solid var(--border-focus);
    border-radius: var(--radius-lg);
    box-shadow: 0 12px 24px -4px rgba(0, 0, 0, 0.5);
    width: 320px;
    max-width: calc(100vw - 32px);
    padding: 16px;
    animation: fadeInScale 0.15s ease-out;
}

.popup-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 12px;
    padding-bottom: 8px;
    border-bottom: 1px solid var(--border-color);
}

.popup-term-wrap {
    display: flex;
    align-items: center;
    gap: 8px;
    flex-wrap: wrap;
}

.popup-term {
    font-size: 18px;
    color: var(--text-main);
}

.popup-phonetic {
    font-size: 13px;
    color: var(--primary);
    font-family: monospace;
}

.popup-close-btn {
    background: none;
    border: none;
    color: var(--text-dim);
    font-size: 16px;
    cursor: pointer;
    padding: 4px;
}

/* Phrasal Verb & Collocation Card in Word Popup */
.popup-phrasal-card {
    background: linear-gradient(135deg, rgba(99, 102, 241, 0.12), rgba(168, 85, 247, 0.08));
    border: 1px solid rgba(99, 102, 241, 0.35);
    border-radius: var(--radius-sm);
    padding: 8px 10px;
    margin-bottom: 10px;
    animation: fadeIn 0.15s ease-out;
}

.phrasal-card-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 4px;
}

.phrasal-tag {
    font-size: 10px;
    font-weight: 700;
    color: var(--primary);
    text-transform: uppercase;
    letter-spacing: 0.04em;
}

.phrasal-term-row {
    display: flex;
    align-items: baseline;
    gap: 6px;
    flex-wrap: wrap;
    margin-bottom: 2px;
}

.phrasal-term {
    font-size: 14px;
    color: var(--text-main);
}

.phrasal-raw {
    font-size: 11px;
    color: var(--text-muted);
    font-style: italic;
}

.phrasal-translation {
    font-size: 12px;
    font-weight: 600;
    color: var(--success);
    margin-bottom: 6px;
    line-height: 1.35;
}

.phrasal-card-actions {
    display: flex;
    gap: 6px;
    margin-top: 4px;
}

.phrasal-action-btn {
    font-size: 11px;
    padding: 3px 8px;
    width: 100%;
    justify-content: center;
}

.popup-translation {
    font-size: 15px;
    font-weight: 600;
    color: var(--success);
    margin-bottom: 8px;
}

.popup-context-box {
    margin-bottom: 14px;
}

.popup-context {
    font-size: 12px;
    color: var(--text-muted);
    font-style: italic;
    background: var(--bg-input);
    padding: 8px 10px;
    border-radius: var(--radius-sm);
    margin-bottom: 6px;
    line-height: 1.4;
    border-left: 3px solid var(--primary);
}

.popup-sentence-ai-bar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 8px;
    margin-bottom: 6px;
}

.popup-sentence-btn {
    font-size: 11px;
    padding: 3px 8px;
    cursor: pointer;
    border-radius: var(--radius-sm);
    display: inline-flex;
    align-items: center;
    gap: 4px;
}

.popup-ai-source-badge {
    font-size: 10px;
    font-weight: 600;
    color: var(--primary);
    background: rgba(99, 102, 241, 0.12);
    border: 1px solid rgba(99, 102, 241, 0.25);
    padding: 2px 6px;
    border-radius: 9999px;
    letter-spacing: 0.02em;
}

.popup-sentence-loading {
    font-size: 11px;
    color: var(--text-muted);
    padding: 6px 8px;
    display: flex;
    align-items: center;
    gap: 6px;
    background: var(--bg-input);
    border-radius: var(--radius-sm);
    margin-bottom: 6px;
}

.popup-sentence-translation-wrap {
    background: rgba(99, 102, 241, 0.08);
    border: 1px solid rgba(99, 102, 241, 0.2);
    border-radius: var(--radius-sm);
    padding: 8px 10px;
    margin-bottom: 6px;
    animation: fadeIn 0.15s ease-out;
}

.popup-sentence-ru {
    font-size: 13px;
    line-height: 1.45;
    color: var(--text-main);
    margin-bottom: 6px;
}

.popup-context-meaning-wrap {
    display: flex;
    align-items: center;
    flex-wrap: wrap;
    gap: 6px;
    font-size: 11px;
    padding-top: 6px;
    border-top: 1px dashed rgba(99, 102, 241, 0.2);
}

.context-meaning-label {
    color: var(--text-muted);
}

.context-meaning-val {
    color: var(--success);
    font-weight: 600;
}

.use-meaning-btn {
    font-size: 10px;
    padding: 1px 6px;
    color: var(--primary);
    border: 1px solid var(--primary);
    border-radius: 4px;
    cursor: pointer;
    background: transparent;
}

.use-meaning-btn:hover {
    background: rgba(99, 102, 241, 0.15);
}

.popup-saved-badge {
    text-align: center;
    font-size: 13px;
    font-weight: 600;
    color: #f59e0b;
    background: rgba(245, 158, 11, 0.12);
    border: 1px solid rgba(245, 158, 11, 0.3);
    border-radius: var(--radius-sm);
    padding: 6px 10px;
}

.popup-in-library-badge {
    display: inline-flex;
    align-items: center;
    gap: 3px;
    font-size: 11px;
    font-weight: 600;
    color: #f59e0b;
    background: rgba(245, 158, 11, 0.15);
    border: 1px solid rgba(245, 158, 11, 0.4);
    padding: 2px 7px;
    border-radius: 9999px;
    margin-left: 6px;
    letter-spacing: 0.02em;
    vertical-align: middle;
}

.badge-library-star {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    font-size: 12px;
    font-weight: 600;
    color: #f59e0b;
    background: rgba(245, 158, 11, 0.15);
    border: 1px solid rgba(245, 158, 11, 0.4);
    padding: 2px 8px;
    border-radius: 9999px;
    margin-left: 8px;
    vertical-align: middle;
}

/* ==========================================================================
   Continuous Reading & Chapter End Navigation Card
   ========================================================================== */

/* Chapter Divider (Between chapters in continuous / autoload mode) */
.reader-chapter-divider {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    margin: 56px 0 36px;
    padding: 24px 16px;
    border-top: 1px dashed var(--border-color);
    border-bottom: 1px dashed var(--border-color);
    background: rgba(255, 255, 255, 0.02);
    border-radius: var(--radius-md);
    text-align: center;
    scroll-margin-top: 60px;
}

.reader-chapter-divider .divider-badge {
    font-size: 11px;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.8px;
    color: var(--primary);
    background: var(--bg-input);
    padding: 4px 12px;
    border-radius: 9999px;
    border: 1px solid var(--border-color);
    margin-bottom: 10px;
    display: inline-block;
}

.reader-chapter-divider .divider-title {
    font-size: 22px !important;
    font-weight: 700;
    color: var(--text-main);
    margin: 0 !important;
    border-bottom: none !important;
    padding-bottom: 0 !important;
    text-align: center;
}

/* Chapter End Navigation Card */
.reader-chapter-footer {
    margin: 48px 0 64px;
    padding: 24px 20px;
    background: var(--bg-surface);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.15);
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    gap: 14px;
    transition: var(--transition);
}

.reader-chapter-footer .chapter-footer-status {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 14px;
    font-weight: 600;
    color: var(--text-muted);
}

.reader-chapter-footer .chapter-footer-status .status-check {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 24px;
    height: 24px;
    border-radius: 50%;
    background: rgba(34, 197, 94, 0.15);
    color: var(--success);
    font-size: 13px;
    font-weight: 700;
}

.reader-chapter-footer .chapter-footer-nav {
    display: flex;
    gap: 12px;
    width: 100%;
    max-width: 540px;
    justify-content: center;
    flex-wrap: wrap;
}

.reader-chapter-footer .reader-footer-nav-btn {
    flex: 1;
    min-width: 150px;
    min-height: 44px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
    font-size: 14px;
    font-weight: 600;
    padding: 10px 18px;
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: var(--transition);
}

.reader-chapter-footer .chapter-footer-hint {
    font-size: 12px;
    color: var(--text-dim);
    line-height: 1.4;
    max-width: 480px;
}

/* Book Completion Card */
.reader-chapter-footer.reader-book-finished {
    background: linear-gradient(180deg, rgba(56, 189, 248, 0.08) 0%, rgba(20, 24, 32, 0.95) 100%);
    border-color: rgba(56, 189, 248, 0.35);
}

.reader-chapter-footer.reader-book-finished .chapter-footer-hint {
    color: var(--text-muted);
    font-size: 13px;
}

/* Reading Theme Adaptations */
.reader-scroll-area.reader-theme-sepia .reader-chapter-divider,
.reader-scroll-area.reader-theme-light .reader-chapter-divider {
    background: rgba(0, 0, 0, 0.025);
    border-color: rgba(0, 0, 0, 0.12);
}

.reader-scroll-area.reader-theme-sepia .reader-chapter-footer,
.reader-scroll-area.reader-theme-light .reader-chapter-footer {
    background: rgba(0, 0, 0, 0.03);
    border-color: rgba(0, 0, 0, 0.12);
    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.06);
}

.reader-scroll-area.reader-theme-oled .reader-chapter-divider {
    background: #080808;
    border-color: #222;
}

.reader-scroll-area.reader-theme-oled .reader-chapter-footer {
    background: #0c0c0c;
    border-color: #222;
}


/* --- Responsive Mobile Overrides (max-width: 768px) --- */
@media (max-width: 768px) {
    /* 6. Bookshelf & Reader View */
    .reader-view {
        padding: 14px 12px calc(76px + env(safe-area-inset-bottom, 0px));
    }

    .bookshelf-header {
        flex-direction: column;
        align-items: stretch;
        gap: 12px;
        margin-bottom: 18px;
    }

    .bookshelf-title-wrap h2 {
        font-size: 19px;
    }

    .bookshelf-actions {
        width: 100%;
        display: flex;
        gap: 8px;
    }

    .bookshelf-actions .btn,
    .bookshelf-actions .file-upload-label {
        flex: 1;
        justify-content: center;
        text-align: center;
        padding: 10px;
    }

    .bookshelf-grid {
        grid-template-columns: 1fr;
        gap: 12px;
    }

    .book-card {
        padding: 14px;
    }

    /* Reader Interface Toolbar */
    .reader-toolbar {
        position: static !important;
        top: auto !important;
        box-shadow: none !important;
        padding: 8px 10px;
        gap: 8px;
        flex-direction: column;
        align-items: stretch;
    }

    .reader-toolbar-left {
        width: 100%;
        justify-content: space-between;
        gap: 8px;
    }

    .reader-meta {
        flex: 1;
        min-width: 0;
    }

    .reader-title {
        font-size: 14px;
        white-space: nowrap;
        overflow: hidden;
        text-overflow: ellipsis;
    }

    .reader-author {
        font-size: 11px;
    }

    .reader-toolbar-center {
        width: 100%;
        justify-content: space-between;
        gap: 6px;
    }

    .reader-select {
        flex: 1;
        max-width: none;
        min-width: 0;
    }

    .reader-toolbar-right {
        width: 100%;
        justify-content: space-between;
        gap: 6px;
        border-top: 1px solid var(--border-color);
        padding-top: 6px;
    }

    .reader-content-body {
        padding: 14px 12px;
        font-size: 17px;
        line-height: 1.65;
    }


}