:root {
    --primary-color: #087EA4;
    --page-color: #fff;
    --paper-color: #fffef8;
    --border-color: #e0e0e0;
    --text-color: #333;
    --shadow-color: rgba(0, 0, 0, 0.2);
    --gutter-color: rgba(0, 0, 0, 0.03);
    --highlight-color: rgba(8, 126, 164, 0.15);
}

.book-container {
    display: flex;
    flex-direction: column;
    align-items: center;
    margin-top: var(--navbar-height);
    padding: 2rem 1rem;
    max-width: 100%;
    overflow-x: hidden;
}

.book-controls {
    /* display: flex; */
    justify-content: right;
    align-items: center;
    /* margin-bottom: 1.5rem;*/
    gap: 1rem;
    width: 100%;
    max-width: 1200px;
}

    .book-controls button,
    .book-controls select {
        padding: 0.5rem 1rem;
        border: 1px solid var(--border-color);
        border-radius: 4px;
        background-color: white;
        font-size: 0.9rem;
        color: #333;
        cursor: pointer;
        transition: all 0.2s;
    }

        .book-controls button:hover {
            background-color: #f0f8ff;
            border-color: var(--primary-color);
        }

        .book-controls select:focus {
            outline: none;
            border-color: var(--primary-color);
        }

.control-btn {
    margin-right: 0.5rem;
    align-items: center;
    display: flex;
    gap: 0.5em;
}

/* Dropdown already uses position:absolute; right:0; so it opens under the button and to the left */
.text-settings-dropdown {
    position: relative;
}

.page-nav-label {
    font-size: 0.9rem;
    color: #666;
    white-space: nowrap;
}

.page-number-input {
    padding: 0.45rem 0.5rem;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    text-align: center;
    font-size: 0.9rem;
}

    .page-number-input:focus {
        outline: none;
        border-color: var(--primary-color);
    }

    .page-number-input.invalid {
        border-color: #ff3860;
        background-color: rgba(255, 56, 96, 0.05);
    }

.book-reader {
    display: grid;
    grid-template-columns: 1fr 1fr;
    grid-template-rows: 1fr auto;
    width: 100%;
    max-width: 1200px;
    height: 80vh;
    box-shadow: 0 4px 10px var(--shadow-color);
    border-radius: 4px;
    position: relative;
    background-color: var(--gutter-color);
    overflow: visible;
}

.book-page {
    width: 50%;
    height: 100%;
    background-color: var(--paper-color);
    box-sizing: border-box;
    position: relative;
    overflow: hidden;
    display: flex;
    flex-direction: column;
    transition: all 0.3s ease;
}

/* Grid placement for pages */
.book-reader .book-page {
    grid-row: 1;
    width: auto;
    height: auto;
    min-height: 0;
}

.left-page {
    border-right: 1px solid var(--border-color);
    border-top-left-radius: 4px;
    border-bottom-left-radius: 4px;
    box-shadow: inset -7px 0 20px -7px rgba(0, 0, 0, 0.1);
    grid-column: 1;
}

.right-page {
    border-left: 1px solid var(--border-color);
    border-top-right-radius: 4px;
    border-bottom-right-radius: 4px;
    box-shadow: inset 7px 0 20px -7px rgba(0, 0, 0, 0.1);
    grid-column: 2;
}

.page-header {
    padding: 1.5rem 2rem 0.5rem;
    border-bottom: 1px solid var(--border-color);
}

.page-language {
    font-size: 0.9rem;
    color: #666;
    margin-bottom: 0.5rem;
}

.page-title {
    font-size: 1.2rem;
    font-weight: 600;
    color: var(--text-color);
    margin-bottom: 0.5rem;
}

.page-reference {
    font-size: 0.8rem;
    color: #888;
    font-style: italic;
}

.page-content {
    padding: 2.5rem 2.5rem;
    overflow-y: auto;
    flex-grow: 1;
    line-height: 1.8;
    font-size: 1.05rem;
    position: relative;
    text-align: justify;
    min-height: 0;
}

.page-content {
    scroll-behavior: smooth;
}

.pagination-controls {
    display: flex;
    justify-content: space-between;
    padding: 1rem 2rem;
    background-color: var(--page-color);
    border-top: 1px solid var(--border-color);
}

.page-number {
    font-size: 0.9rem;
    color: #888;
}

.page-buttons {
    display: flex;
    gap: 1rem;
}

.page-btn {
    background: none;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    padding: 0.3rem 0.8rem;
    cursor: pointer;
    color: #555;
    transition: all 0.2s;
}

    .page-btn:hover {
        background-color: #f0f8ff;
        border-color: var(--primary-color);
        color: var(--primary-color);
    }

    .page-btn:disabled {
        background-color: #f5f5f5;
        color: #ccc;
        cursor: not-allowed;
    }

.chapter-dropdown {
    position: relative;
    display: inline-block;
}

.dropdown-toggle {
    cursor: pointer;
}

.chapter-dropdown-content {
    display: none;
    position: absolute;
    right: 0;
    top: 100%;
    background-color: white;
    min-width: 240px;
    max-height: 300px;
    overflow-y: auto;
    box-shadow: 0 8px 16px rgba(0,0,0,0.1);
    z-index: 10;
    border-radius: 4px;
    padding: 0.5rem 0;
    border: 1px solid var(--border-color);
}

    .chapter-dropdown-content.show {
        display: block;
    }

.chapter-option {
    padding: 0.75rem 1rem;
    cursor: pointer;
    transition: background-color 0.2s;
}

    .chapter-option:hover {
        background-color: #f0f8ff;
    }

    .chapter-option.active {
        background-color: #e6f3ff;
        font-weight: 500;
    }

.sidebar-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.5);
    z-index: 999;
    display: none;
}

.overlay-visible {
    display: block;
}

/* Page-turning effects */
.page-turning {
    position: relative;
    transition: transform 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275), opacity 0.3s ease;
}

.page-turning-left {
    transform: perspective(1500px) rotateY(-8deg);
    transform-origin: right center;
    box-shadow: -5px 5px 20px rgba(0, 0, 0, 0.15);
    opacity: 0.95;
}


.page-turning-right {
    transform: perspective(1500px) rotateY(8deg);
    transform-origin: left center;
    box-shadow: 5px 5px 20px rgba(0, 0, 0, 0.15);
    opacity: 0.95;
}

.text-settings-dropdown {
    position: relative;
    display: inline-block;
}

.text-settings-content {
    display: none;
    position: absolute;
    right: 0;
    background-color: white;
    min-width: 240px;
    box-shadow: 0 8px 16px rgba(0,0,0,0.1);
    z-index: 10;
    border-radius: 4px;
    padding: 1rem;
    border: 1px solid var(--border-color);
}

    .text-settings-content.show {
        display: block;
    }

.settings-group {
    margin-bottom: 1rem;
}

.settings-label {
    display: block;
    margin-bottom: 0.5rem;
    font-size: 0.9rem;
    color: #666;
}

.settings-control {
    width: 100%;
    padding: 0.4rem;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    align-items: center;
    display: flex;
    gap: 0.5em;
    justify-content: center;
    background-color: white;
}

/* Side navigation controls */
.page-nav-control {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    z-index: 100;
    display: flex;
    align-items: center;
    justify-content: center;
    width: 50px;
    height: 100px;
}

.prev-page-control {
    left: -25px;
}

.next-page-control {
    right: -25px;
}

.page-nav-btn {
    background: none;
    border: none;
    font-size: 2rem;
    color: #555;
    cursor: pointer;
    padding: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 60px;
    transition: all 0.2s ease;
    background-color: rgba(255, 255, 255, 0.9);
    border-radius: 5px;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
}

    .page-nav-btn:hover {
        color: var(--primary-color);
        box-shadow: 0 3px 8px rgba(0, 0, 0, 0.15);
    }

    .page-nav-btn:disabled {
        color: #ccc;
        cursor: not-allowed;
        box-shadow: none;
    }

    .page-nav-btn .icon {
        width: 36px;
        height: 36px;
    }

/* Span interaction styles */
[data-span-id] {
    transition: background-color 0.2s ease;
    cursor: pointer;
    border-radius: 2px;
}

span[class^="span"] {
    transition: background-color 0.2s ease;
    cursor: pointer;
    border-radius: 2px;
}

.book-title-display {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--text-color);
    margin: 0;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    max-width: 50%;
}

/* Book title and author styling for first page */
.page-book-title {
    text-align: center;
    padding-top: 1rem;
    font-size: 1.8em;
    font-weight: 600;
    margin-bottom: 2rem;
    line-height: 1.2;
}

.page-book-author {
    text-align: center;
    font-size: 1.4em;
    font-weight: 500;
    color: #444;
    margin-bottom: 2rem;
}

.navigation-hints {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 2rem;
    margin-top: 1rem;
    padding: 0.5rem;
}

.keyboard-key-hint {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.9rem;
    color: #666;
}

.key-icon {
    display: flex;
    align-items: center;
    justify-content: center;
    min-width: 2.2rem;
    height: 1.8rem;
    background-color: #f5f5f5;
    border: 1px solid #ddd;
    border-radius: 4px;
    box-shadow: 0 2px 2px rgba(0,0,0,0.1);
    font-family: monospace;
    font-size: 1rem;
    font-weight: bold;
}

.hint-item {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.9rem;
}

    .hint-item i {
        font-size: 1rem;
    }

.back-link {
    color: #555;
    text-decoration: none;
    font-size: 0.95rem;
    transition: color 0.2s;
    text-align: center;
}

    .back-link:hover {
        color: #0066cc;
    }

.fullscreen-mode {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 9000;
    background-color: white;
    padding: 1rem;
    display: flex;
    flex-direction: column;
    align-items: center;
}

    .fullscreen-mode .book-reader {
        height: 100%;
        max-width: 90vw;
    }

    .fullscreen-mode .book-controls {
        margin: 0;
        margin-bottom: 0;
    }

    .fullscreen-mode .key-icon {
        background-color: #eaeaea;
        border-color: #ccc;
    }

    /* Hide everything except essentials in fullscreen mode */
    .fullscreen-mode .navbar,
    .fullscreen-mode .footer,
    .fullscreen-mode .sidebar-container {
        display: none !important;
    }

/* Mobile Responsive Styles */
@media (max-width: 768px) {
    .navbar {
        display: none;
    }

    .search-dropdown {
        display: none;
    }

    .mobile-menu {
        display: none;
    }
    /* Full screen layout for mobile */
    .book-container {
        margin-top: 0;
        padding: 0;
        height: 100vh;
        max-width: 100%;
    }

    .book-controls {
        display: none;
    }

    .navigation-hints {
        display: none;
    }

    .book-reader {
        display: flex;
        flex-direction: column;
        height: 100vh;
        max-width: 100%;
        width: 100%;
        border-radius: 0;
        box-shadow: none;
        background-color: transparent;
    }
    /* Adjust page layout for vertical stacking */
    .book-page {
        width: 100%;
        height: 50%;
        border-radius: 0;
    }

    .book-reader .book-page {
        width: 100%;
        height: 50%;
    }
    /* Remove side borders and shadows, add horizontal divider */
    .left-page {
        border-right: none;
        border-bottom: 1px solid var(--border-color);
        border-top-left-radius: 0;
        border-bottom-left-radius: 0;
        box-shadow: none;
        order: 1; /* Place original text at top */
    }

    .right-page {
        border-left: none;
        border-bottom: 1px solid var(--border-color);
        border-top-right-radius: 0;
        border-bottom-right-radius: 0;
        box-shadow: none;
        order: 2; /* Place translation at bottom */
    }
    /* Adjust page content padding for mobile */
    .page-content {
        padding: 1rem;
        font-size: 0.95rem;
        line-height: 1.6;
    }
    /* Reposition navigation controls to the center between pages */
    .page-nav-control {
        position: absolute;
        top: 50%;
        transform: translateY(-50%);
        z-index: 100;
        left: 50%;
        transform: translate(-50%, -50%);
        width: auto;
        height: auto;
    }

    .prev-page-control {
        left: 5%;
        transform: translate(-50%, -50%);
    }

    .next-page-control {
        left: 95%;
        transform: translate(-50%, -50%);
    }
    /* Adjust navigation button styles for mobile */
    .page-nav-btn {
        width: 40px;
        height: 40px;
        font-size: 1.5rem;
        background-color: rgba(255, 255, 255, 0.95);
        border: 2px solid var(--border-color);
        /* border-radius: 50%; */
        box-shadow: 0 4px 8px rgba(0, 0, 0, 0.15);
    }

        .page-nav-btn:hover {
            background-color: rgba(255, 255, 255, 1);
            transform: scale(1.05);
        }
    /* Remove page headers on mobile for more space */
    .page-header {
        display: none;
    }
    /* Ensure no scrollbars appear */
    .page-content {
        overflow: hidden;
    }
    /* Adjust page turning animations for vertical layout */
    .page-turning-left {
        transform: perspective(1500px) rotateX(-8deg);
        transform-origin: center bottom;
    }

    .page-turning-right {
        transform: perspective(1500px) rotateX(8deg);
        transform-origin: center top;
    }
}

/* Landscape mobile adjustments */
@media (max-width: 768px) and (orientation: landscape) {
    .page-content {
        padding: 0.5rem;
        font-size: 0.9rem;
    }

    .page-nav-btn {
        width: 40px;
        height: 40px;
        font-size: 1.2rem;
    }
}

.mobile-page-info {
    display: none;
    justify-content: space-between;
    align-items: center;
    padding: 0.5rem 1rem;
    background-color: var(--page-color);
    border-top: 1px solid var(--border-color);
    font-size: 0.9rem;
}

.mobile-page-navigation {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.mobile-page-label {
    font-size: 0.9rem;
    color: #666;
    white-space: nowrap;
}

.mobile-page-input {
    padding: 0.3rem 0.4rem;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    text-align: center;
    font-size: 0.9rem;
    width: 50px;
}

    .mobile-page-input:focus {
        outline: none;
        border-color: var(--primary-color);
    }

    .mobile-page-input.invalid {
        border-color: #ff3860;
        background-color: rgba(255, 56, 96, 0.05);
    }

.mobile-page-separator {
    font-size: 0.9rem;
    color: #666;
}

.mobile-settings-dropdown {
    position: relative;
    display: inline-block;
}

.mobile-settings-btn {
    background: none;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    padding: 0.4rem 0.6rem;
    cursor: pointer;
    color: #555;
    transition: all 0.2s;
    font-size: 0.9rem;
    display: flex;
    align-content: center;
    justify-content: center;
}

    .mobile-settings-btn:hover {
        background-color: #f0f8ff;
        border-color: var(--primary-color);
        color: var(--primary-color);
    }

.mobile-sidebar {
    display: none;
}

/* Mobile Sidebar Styles */
@media (max-width: 768px) {
    .mobile-page-info {
        display: flex;
    }

    .mobile-sidebar-overlay {
        position: fixed;
        top: 0;
        left: 0;
        width: 100%;
        height: 100%;
        background-color: rgba(0, 0, 0, 0.5);
        z-index: 999;
        opacity: 0;
        visibility: hidden;
        transition: opacity 0.3s ease, visibility 0.3s ease;
    }

        .mobile-sidebar-overlay.active {
            opacity: 1;
            visibility: visible;
        }

    .mobile-sidebar {
        display: flex;
        position: fixed;
        top: 0;
        right: -90%;
        width: 90%;
        height: 100%;
        background-color: white;
        z-index: 1000;
        transition: right 0.3s ease;
        display: flex;
        flex-direction: column;
        /* box-shadow: -4px 0 20px rgba(0, 0, 0, 0.15); */
    }

        .mobile-sidebar.active {
            right: 0;
        }

        .mobile-sidebar .icon {
            margin-right: 0.5rem;
            color: var(--primary-color);
        }

    .sidebar-header {
        display: flex;
        justify-content: space-between;
        align-items: center;
        padding: 1rem 1.5rem;
        /* background-color: var(--primary-color); */
        color: var(--text-color);
        border-bottom: 1px solid var(--border-color);
    }

        .sidebar-header h3 {
            margin: 0;
            font-size: 1.2rem;
            font-weight: 600;
            display: flex;
            align-items: center;
        }

            .sidebar-header h3 i {
                margin-right: 0.5rem;
                color: var(--primary-color);
            }

    .sidebar-close-btn {
        background: none;
        border: none;
        color: white;
        font-size: 1.5rem;
        cursor: pointer;
        padding: 0.25rem;
        border-radius: 4px;
        transition: background-color 0.2s;
    }

        .sidebar-close-btn:hover {
            background-color: rgba(255, 255, 255, 0.1);
        }

    .sidebar-content {
        flex: 1;
        overflow-y: auto;
        padding: 0;
    }

    .sidebar-section {
        padding: 1.5rem;
        border-bottom: 1px solid #f0f0f0;
    }

        .sidebar-section:last-child {
            border-bottom: none;
        }

        .sidebar-section h4 {
            margin: 0 0 1rem 0;
            font-size: 1rem;
            font-weight: 600;
            color: var(--text-color);
            display: flex;
            align-items: center;
        }

            .sidebar-section h4 i {
                margin-right: 0.5rem;
                color: var(--primary-color);
            }

    .current-reading-info p {
        margin: 0 0 0.5rem 0;
        font-size: 0.9rem;
        color: #666;
    }

    .book-links {
        margin: 0.5rem 0;
    }

    .book-link {
        color: var(--primary-color);
        text-decoration: none;
        font-weight: 500;
        font-size: 0.9rem;
    }

        .book-link:hover {
            text-decoration: underline;
        }

    .separator {
        margin: 0 0.5rem;
        color: #999;
    }

    .ai-note {
        font-size: 0.8rem;
        color: #888;
        font-style: italic;
    }

    .sidebar-nav-control {
        display: flex;
        flex-direction: column;
        gap: 0.5rem;
    }

    .nav-input-group {
        display: flex;
        align-items: center;
        gap: 0.5rem;
        flex-wrap: wrap;
    }

    .sidebar-page-input {
        width: 60px;
        padding: 0.4rem;
        border: 1px solid var(--border-color);
        border-radius: 4px;
        text-align: center;
        font-size: 0.9rem;
    }

    .nav-separator {
        font-size: 0.9rem;
        color: #666;
    }

    .sidebar-btn-small {
        padding: 0.4rem 0.8rem;
        background-color: var(--primary-color);
        color: white;
        border: none;
        border-radius: 4px;
        font-size: 0.85rem;
        cursor: pointer;
        transition: background-color 0.2s;
    }

        .sidebar-btn-small:hover {
            background-color: #065a7a;
        }

    .sidebar-control-group {
        margin-bottom: 1rem;
    }

        .sidebar-control-group:last-child {
            margin-bottom: 0;
        }

    .sidebar-label {
        display: block;
        margin-bottom: 0.5rem;
        font-size: 0.9rem;
        color: #666;
        font-weight: 500;
    }

    .sidebar-control {
        width: 100%;
        padding: 0.5rem;
        border: 1px solid var(--border-color);
        border-radius: 4px;
        font-size: 0.9rem;
        background-color: white;
        color: #333;
    }

        .sidebar-control:focus {
            outline: none;
            border-color: var(--primary-color);
        }

    .sidebar-btn {
        display: block;
        /* width: 100%; */
        padding: 0.75rem 1rem;
        margin-bottom: 0.75rem;
        background-color: var(--primary-color);
        color: white;
        border: none;
        border-radius: 4px;
        font-size: 0.9rem;
        text-decoration: none;
        text-align: center;
        cursor: pointer;
        transition: background-color 0.2s;
    }

        .sidebar-btn:hover {
            background-color: #065a7a;
            color: white;
            text-decoration: none;
        }

        .sidebar-btn:last-child {
            margin-bottom: 0;
        }

    .sidebar-btn-secondary {
        background-color: #6c757d;
        display: flex;
        align-content: center;
        justify-content: center;
    }

        .sidebar-btn-secondary:hover {
            background-color: #545b62;
        }

        .sidebar-btn-secondary .icon {
            color: white;
        }

    .sidebar-btn-outline {
        background-color: transparent;
        color: var(--primary-color);
        border: 2px solid var(--primary-color);
    }

        .sidebar-btn-outline:hover {
            background-color: var(--primary-color);
            color: white;
        }

    .sidebar-btn i {
        margin-right: 0.5rem;
    }
}

.span-share-tooltip {
    position: absolute;
    z-index: 1000;
    background: white;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
    padding: 0;
    min-width: 280px;
    max-width: 320px;
}

.tooltip-content {
    display: flex;
    align-items: center;
    padding: 8px;
    gap: 8px;
}

.tooltip-url {
    flex: 1;
}

.url-input {
    width: 100%;
    padding: 6px 8px;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    font-size: 12px;
    font-family: monospace;
    background: #f8f9fa;
    color: #666;
    outline: none;
}

    .url-input:focus {
        border-color: var(--primary-color);
    }

.tooltip-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 6px;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    background: white;
    color: #666;
    cursor: pointer;
    transition: all 0.2s;
    min-width: 32px;
    height: 32px;
    position: relative;
}

    .tooltip-btn:hover {
        background: var(--primary-color);
        color: white;
        border-color: var(--primary-color);
    }

    .tooltip-btn .btn-spinner {
        display: none;
        width: 16px;
        height: 16px;
        border: 2px solid #cfcfcf;
        border-top-color: #555;
        border-radius: 50%;
        animation: spin 0.8s linear infinite;
    }

    .tooltip-btn.loading .btn-spinner {
        display: inline-block;
    }

    .tooltip-btn.loading svg {
        display: none;
    }

    .tooltip-btn.disabled {
        background: #f5f5f5;
        color: #f00;
        border-color: #e0e0e0;
        cursor: not-allowed;
        opacity: 0.6;
    }

        .tooltip-btn.disabled:hover {
            background: #f5f5f5 !important;
            color: #f00 !important;
            border-color: #e0e0e0 !important;
            transform: none !important;
        }

        /* Override hover effects for disabled buttons */
        .tooltip-btn.disabled svg {
            opacity: 0.5;
        }

    /* Ensure disabled attribute also applies styles */
    .tooltip-btn:disabled {
        background: #f5f5f5;
        color: #f00;
        border-color: #e0e0e0;
        cursor: not-allowed;
        opacity: 0.6;
    }

        .tooltip-btn:disabled:hover {
            background: #f5f5f5 !important;
            color: #f00 !important;
            border-color: #e0e0e0 !important;
            transform: none !important;
        }

        .tooltip-btn:disabled svg {
            opacity: 0.5;
        }

    /* Custom tooltip for better UX (optional enhancement) */
    .tooltip-btn.disabled {
        position: relative;
    }

        .tooltip-btn.disabled::after {
            content: attr(title);
            position: absolute;
            bottom: 100%;
            left: 50%;
            transform: translateX(-50%);
            background: #333;
            color: white;
            padding: 4px 8px;
            border-radius: 4px;
            font-size: 12px;
            white-space: nowrap;
            opacity: 0;
            visibility: hidden;
            transition: opacity 0.2s;
            z-index: 1000;
            margin-bottom: 5px;
            pointer-events: none;
        }

        .tooltip-btn.disabled::before {
            content: '';
            position: absolute;
            bottom: 100%;
            left: 50%;
            transform: translateX(-50%);
            border-left: 5px solid transparent;
            border-right: 5px solid transparent;
            border-top: 5px solid #333;
            opacity: 0;
            visibility: hidden;
            transition: opacity 0.2s;
            z-index: 1000;
            pointer-events: none;
        }

        .tooltip-btn.disabled:hover::after,
        .tooltip-btn.disabled:hover::before {
            opacity: 1;
            visibility: visible;
        }

/* Mobile responsive adjustments for disabled state */
@media (max-width: 768px) {
    .tooltip-btn.disabled::after {
        font-size: 11px;
        padding: 3px 6px;
    }
}

.copy-btn:active {
    transform: scale(0.95);
}

.copy-btn {
    margin-left: 20px;
}

/* Mobile responsive adjustments */
@media (max-width: 768px) {
    .span-share-tooltip {
        min-width: 250px;
        max-width: 280px;
        font-size: 14px;
    }

    .url-input {
        font-size: 11px;
        padding: 8px;
    }

    .copy-btn {
        min-width: 36px;
        height: 36px;
    }
}

.selection-listen-tooltip {
    position: absolute;
    z-index: 1001; /* just above span-share-tooltip */
    background: white;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    box-shadow: 0 4px 12px rgba(0,0,0,0.15);
    padding: 4px;
    min-width: 44px;
    display: none;
    user-select: none;
}

    .selection-listen-tooltip .tooltip-content {
        padding: 4px;
        gap: 0;
        justify-content: center;
    }

    .selection-listen-tooltip .tooltip-btn {
        min-width: 36px;
        height: 36px;
    }

.copy-success {
    background: #28a745 !important;
    color: white !important;
    border-color: #28a745 !important;
}

/* Span highlighting for shared spans */
.span-shared {
    background-color: var(--highlight-color);
}

.book-reader-loading {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: rgba(255, 255, 255, 0.8);
    backdrop-filter: blur(2px);
    display: none;
    justify-content: center;
    align-items: center;
    z-index: 500;
    border-radius: 4px;
}

    .book-reader-loading.show {
        display: flex;
    }

.loading-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1rem;
    padding: 2rem;
    background-color: rgba(255, 255, 255, 0.95);
    border-radius: 8px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
}

.loading-spinner {
    width: 40px;
    height: 40px;
    border: 3px solid #f0f0f0;
    border-top: 3px solid var(--primary-color);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    0% {
        transform: rotate(0deg);
    }

    100% {
        transform: rotate(360deg);
    }
}

.loading-text {
    font-size: 0.95rem;
    color: #666;
    text-align: center;
    margin: 0;
}

/* Greyed out book pages during loading */
.book-reader.loading .book-page {
    opacity: 0.6;
    pointer-events: none;
    transition: opacity 0.3s ease;
}

.book-reader.loading .page-nav-control {
    opacity: 0.5;
    pointer-events: none;
}

/* Mobile loading adjustments */
@media (max-width: 768px) {
    .loading-content {
        padding: 1.5rem;
    }

    .loading-spinner {
        width: 36px;
        height: 36px;
        border-width: 2px;
    }

    .loading-text {
        font-size: 0.9rem;
    }
}

/* Draggable AI window */
.ai-panel {
    position: absolute;
    top: 0;
    left: 0;
    width: 340px;
    max-width: min(90vw, 380px);
    max-height: 50vh;
    background: #fff;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    box-shadow: 0 10px 24px rgba(0,0,0,0.2);
    z-index: 1200;
    display: flex;
    flex-direction: column;
    user-select: auto;
}

.ai-panel-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 8px;
    padding: 8px 10px;
    background: #f8f9fa;
    border-bottom: 1px solid var(--border-color);
    border-top-left-radius: 8px;
    border-top-right-radius: 8px;
    cursor: move;
    user-select: none;
}

.ai-panel-title {
    display: flex;
    align-items: center;
    gap: 6px;
    font-weight: 600;
    color: #333;
    font-size: 0.95rem;
}

.ai-panel-actions {
    display: flex;
    gap: 6px;
}

    .ai-panel-actions button {
        border: 1px solid var(--border-color);
        background: white;
        border-radius: 4px;
        width: 28px;
        height: 28px;
        display: inline-flex;
        align-items: center;
        justify-content: center;
        cursor: pointer;
    }

        .ai-panel-actions button:hover {
            background: var(--primary-color);
            color: white;
            border-color: var(--primary-color);
        }

.ai-panel-body {
    overflow: auto;
    white-space: pre-wrap;
    word-break: break-word;
    font-size: 0.95rem;
    line-height: 1.5;
    overflow-wrap: anywhere;
    padding: 8px 10px;
}

.ai-panel-content {
    white-space: pre-wrap;
}

.ai-panel-content {
    line-height: 1.6;
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
}

.ai-panel-body, .ai-panel-content {
    white-space: normal;
    line-height: 1.25;
    font-size: 0.9rem;
}

    .ai-panel-content h1,
    .ai-panel-content h2,
    .ai-panel-content h3,
    .ai-panel-content h4,
    .ai-panel-content h5,
    .ai-panel-content h6 {
        margin: 0.35em 0 0.2em !important;
        line-height: 1.15;
        font-weight: 600;
    }

    .ai-panel-content p {
        margin: 0.25em 0 !important;
    }

    .ai-panel-content code {
        background-color: #f6f8fa;
        border-radius: 3px;
        font-family: 'SFMono-Regular', Consolas, 'Liberation Mono', Menlo, monospace;
        padding: 1px 3px !important;
    }

    .ai-panel-content pre {
        background-color: #f6f8fa;
        overflow-x: auto;
        border-radius: 4px;
        padding: 8px !important;
        margin: 0.35em 0 !important;
    }

        .ai-panel-content pre code {
            background: none;
            padding: 0;
        }

    .ai-panel-content blockquote {
        border-left: 3px solid #dfe2e5;
        padding-left: 10px;
        margin: 0.25em 0 !important;
        color: #6a737d;
    }

    .ai-panel-content ul,
    .ai-panel-content ol {
        margin: 0.25em 0 !important;
        padding-left: 1.25em;
    }

    .ai-panel-content li {
        margin: 0.1em 0 !important;
    }

@media (max-width: 768px) {
    .ai-panel {
        width: calc(100vw - 24px);
        left: 12px !important;
        top: 12px !important;
        max-height: 60vh;
    }
}

.center-page-control {
    position: static;
    grid-row: 2;
    grid-column: 1 / -1;
    left: 0;
    right: 0;
    bottom: 0;
    transform: none;
    width: 100%;
    box-sizing: border-box;
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.5rem 1rem;
    background: rgba(255, 255, 255, 0.9);
    backdrop-filter: blur(4px);
    border-top: 1px solid var(--border-color);
    color: #888;
    z-index: 1;
    user-select: none;
    background-color: var(--paper-color);
}

    .center-page-control .cp-counter {
        display: inline-flex;
        align-items: center;
        gap: 0.35rem;
        white-space: nowrap;
        margin-left: 0.25rem;
    }

    .center-page-control .cp-label,
    .center-page-control .cp-sep {
        font-size: 0.9rem;
        color: #666;
        white-space: nowrap;
    }

    .center-page-control .cp-input {
        width: 30px;
        padding: 0.2rem 0.25rem;
        text-align: center;
        font-size: 0.9rem;
    }

    .center-page-control .cp-slider {
        flex: 1 1 auto; /* takes all the remaining width */
        min-width: 260px;
        height: 28px;
        background: transparent;
        -webkit-appearance: none;
        appearance: none;
        cursor: pointer;
        --progress: 0%; /* updated via JS for WebKit progress look */
        accent-color: var(--primary-color); /* fallback color for browsers that support it */
    }

        /* WebKit track/thumb */
        .center-page-control .cp-slider::-webkit-slider-runnable-track {
            height: 6px;
            border-radius: 999px;
            background: linear-gradient( to right, var(--primary-color) 0%, var(--primary-color) var(--progress), #e6e6e6 var(--progress), #e6e6e6 100% );
        }

        .center-page-control .cp-slider::-webkit-slider-thumb {
            -webkit-appearance: none;
            appearance: none;
            width: 16px;
            height: 16px;
            border-radius: 50%;
            background: #fff;
            border: 2px solid var(--primary-color);
            margin-top: -5px; /* centers thumb on the 6px track */
            box-shadow: 0 0 0 2px rgba(8,126,164,.12);
        }

        /* Firefox track/progress/thumb */
        .center-page-control .cp-slider::-moz-range-track {
            height: 6px;
            border-radius: 999px;
            background: #e6e6e6;
        }

        .center-page-control .cp-slider::-moz-range-progress {
            height: 6px;
            border-radius: 999px;
            background: var(--primary-color);
        }

        .center-page-control .cp-slider::-moz-range-thumb {
            width: 16px;
            height: 16px;
            border-radius: 50%;
            background: #fff;
            border: 2px solid var(--primary-color);
            box-shadow: 0 0 0 2px rgba(8,126,164,.12);
        }

        /* Disabled state */
        .center-page-control .cp-slider:disabled {
            opacity: .5;
            cursor: not-allowed;
        }

    .center-page-control .cp-actions {
        display: inline-flex;
        align-items: center;
        gap: 0.25rem;
    }

    .center-page-control .cp-btn {
        display: inline-flex;
        align-items: center;
        justify-content: center;
        padding: 0.35rem;
        background-color: transparent;
        border: none;
        border-radius: 4px;
        color: #666;
        cursor: pointer;
        transition: background-color .15s ease, transform .05s ease;
    }

        .center-page-control .cp-btn:hover {
            background-color: rgba(0,0,0,0.05);
        }

        .center-page-control .cp-btn:active {
            transform: translateY(1px);
        }

        .center-page-control .cp-btn:focus-visible {
            outline: 2px solid var(--primary-color);
            outline-offset: 2px;
        }

        .center-page-control .cp-btn .icon {
            width: 18px;
            height: 18px;
            display: block;
        }

            .center-page-control .cp-btn .icon path,
            .center-page-control .cp-btn .icon polygon,
            .center-page-control .cp-btn .icon rect,
            .center-page-control .cp-btn .icon circle,
            .center-page-control .cp-btn .icon line,
            .center-page-control .cp-btn .icon polyline {
                fill: currentColor;
                stroke: currentColor;
            }

    .center-page-control .text-settings-dropdown {
        position: relative;
    }

        .center-page-control .text-settings-dropdown .text-settings-content {
            display: none;
            position: absolute;
            right: 0;
            bottom: calc(100% + 8px);
            top: auto;
            z-index: 400;
        }

            .center-page-control .text-settings-dropdown .text-settings-content.show {
                display: block;
            }

/* hide the gutter control on phones */
@media (max-width: 768px) {
    .center-page-control {
        display: none;
    }
}