:root {
    --primary: #0d6efd;
    --primary-dark: #0a58ca;
    --primary-rgb: 13, 110, 253;
    --bg: #f8f9fa;
    --card: #ffffff;
    --text: #212529;
    --text-inverse: #ffffff;
    --muted: #6c757d;
    --border: #dee2e6;
    --navbar: #0d6efd;
    --input-bg: #ffffff;
    --link: #0d6efd;
}

[data-theme="dark"] {
    --bg: #121416;
    --card: #1e2226;
    --text: #f1f3f5;
    --text-inverse: #121416;
    --muted: #adb5bd;
    --border: #3d4449;
    --input-bg: #2b3035;
    --link: #6ea8fe;
}

/* Readable text everywhere */
body,
.main-content,
.card,
.card-body,
.card-title,
.card-text,
h1,
h2,
h3,
h4,
h5,
h6,
p,
label,
.form-label,
.table,
.list-group-item,
.nav-pills .nav-link,
.catalog-tabs .nav-link,
.modal-content,
.dropdown-menu {
    color: var(--text);
}

body {
    background-color: var(--bg);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Smooth page-level transitions for internal navigation. */
main.main-content {
    opacity: 1;
    transition: opacity 120ms ease-out, transform 120ms ease-out;
}

body.page-enter main.main-content {
    opacity: 0;
    transform: translateY(4px);
}

body.page-enter-active main.main-content {
    opacity: 1;
    transform: none;
}

body.page-leave main.main-content {
    opacity: 0;
    transform: translateY(3px);
}

.text-muted,
small.text-muted,
.form-text {
    color: var(--muted) !important;
}

a:not(.btn):not(.nav-link):not(.navbar-brand):not(.page-link):not(.list-group-item-action) {
    color: var(--link);
}

/* Navbar — contrast-safe, sticky on scroll */
.site-navbar {
    position: sticky;
    top: 0;
    z-index: 1030;
    background: var(--navbar) !important;
}

.site-navbar.navbar-dark .navbar-brand,
.site-navbar.navbar-dark .nav-link,
.site-navbar.navbar-dark .navbar-text {
    color: #fff !important;
}

.site-navbar.navbar-dark .nav-link:hover {
    color: rgba(255, 255, 255, 0.85) !important;
}

.site-navbar.navbar-light .navbar-brand,
.site-navbar.navbar-light .nav-link,
.site-navbar.navbar-light .navbar-text {
    color: #212529 !important;
}

.site-navbar.navbar-light .btn-outline-light {
    border-color: #212529;
    color: #212529;
}

.site-navbar.navbar-light .btn-light {
    background: #212529;
    color: #fff;
    border-color: #212529;
}

.navbar-brand {
    font-weight: 700;
    letter-spacing: 0.5px;
}

.school-logo-nav,
.school-logo-auth,
.school-logo-dashboard,
.school-logo-hero,
.school-logo-report,
.school-logo-preview {
    object-fit: contain;
    max-width: 140px;
    max-height: 56px;
    width: auto;
    height: auto;
    background: rgba(255, 255, 255, 0.15);
    border-radius: 6px;
    padding: 2px 4px;
}

.site-navbar.navbar-light .school-logo-nav,
.site-navbar.navbar-light .school-logo-preview {
    background: rgba(0, 0, 0, 0.06);
}

.brand-title {
    font-size: 1.1rem;
    font-weight: 700;
}

.brand-subtitle {
    font-size: 0.7rem;
}

.main-content {
    flex: 1;
}

.card {
    background: var(--card);
    border-color: var(--border);
    color: var(--text);
    box-shadow: 0 0.125rem 0.25rem rgba(0, 0, 0, 0.06);
}

.card:hover {
    box-shadow: 0 0.5rem 1rem rgba(0, 0, 0, 0.1);
}

.stat-card {
    border-left: 4px solid var(--primary);
    border-radius: 0.5rem;
}

.stat-card-link {
    display: block;
    color: inherit;
    text-decoration: none;
    transition: transform 0.2s, box-shadow 0.2s;
}

.stat-card-link:hover,
.stat-card-link:focus-visible {
    color: inherit;
    transform: translateY(-3px);
    box-shadow: 0 0.5rem 1.25rem rgba(0, 0, 0, 0.12);
}

.stat-card-link:focus-visible {
    outline: 2px solid var(--primary);
    outline-offset: 2px;
}

.stat-card .stat-value {
    font-size: 2rem;
    font-weight: 700;
    color: var(--primary);
}

.category-card {
    transition: transform 0.2s, box-shadow 0.2s;
    cursor: pointer;
    background: var(--card);
    color: var(--text);
}

.category-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 0.5rem 1.25rem rgba(0, 0, 0, 0.12);
}

.category-card h5,
.category-card .text-body {
    color: var(--text) !important;
}

.category-card-icon {
    font-size: 2.5rem;
}

.catalog-tabs .nav-link {
    color: var(--text);
    background: var(--card);
    border: 1px solid var(--border);
    border-radius: 2rem;
    margin: 0.15rem;
}

.catalog-tabs .nav-link:hover {
    background: var(--border);
}

.catalog-tabs .nav-link.active {
    background: var(--primary);
    border-color: var(--primary);
    color: #fff !important;
}

.catalog-sidebar .list-group-item {
    background: var(--card);
    color: var(--text);
    border-color: var(--border);
}

.catalog-sidebar .list-group-item:hover {
    background: var(--border);
    color: var(--text);
}

.catalog-sidebar .list-group-item.active {
    background: var(--primary);
    border-color: var(--primary);
    color: #fff !important;
}

.catalog-sidebar .list-group-item.active .badge {
    background: rgba(255, 255, 255, 0.25) !important;
    color: #fff;
}

.ai-catalog-section {
    background: var(--card);
    border: 1px solid var(--border);
    border-radius: 0.75rem;
    padding: 1.5rem;
    color: var(--text);
}

.ai-rec-card {
    border-left: 3px solid var(--primary);
    background: var(--card);
}

.auth-card {
    border-top: 4px solid var(--primary);
    background: var(--card);
}

.dashboard-brand-bar {
    border-left: 4px solid var(--primary);
    background: var(--card);
}

.book-cover {
    width: 100%;
    height: 220px;
    object-fit: cover;
    border-radius: 0.375rem 0.375rem 0 0;
    background: var(--border);
}

.book-cover-sm {
    width: 80px;
    height: 110px;
    object-fit: cover;
    border-radius: 0.25rem;
}

.hero-section {
    background: linear-gradient(135deg, var(--primary) 0%, #495057 100%);
    color: #fff;
    padding: 4rem 0;
    border-radius: 0 0 1rem 1rem;
}

.hero-section h1,
.hero-section p,
.hero-section .lead {
    color: #fff !important;
}

.recommendation-badge {
    background: linear-gradient(90deg, var(--primary), #6610f2);
    color: #fff;
    font-size: 0.75rem;
}

.score-bar {
    height: 6px;
    border-radius: 3px;
    background: var(--border);
    overflow: hidden;
}

.score-bar-fill {
    height: 100%;
    background: var(--primary);
    border-radius: 3px;
}

.form-control,
.form-select {
    background-color: var(--input-bg);
    color: var(--text);
    border-color: var(--border);
}

.form-control:focus,
.form-select:focus {
    background-color: var(--input-bg);
    color: var(--text);
    border-color: var(--primary);
    box-shadow: 0 0 0 0.2rem rgba(var(--primary-rgb), 0.25);
}

.form-control::placeholder {
    color: var(--muted);
    opacity: 1;
}

.password-toggle {
    border-color: var(--border);
    color: var(--muted);
    background-color: var(--input-bg);
}

.password-toggle:hover,
.password-toggle:focus {
    border-color: var(--border);
    color: var(--text);
    background-color: var(--input-bg);
}

.input-group .form-control:focus {
    z-index: 3;
}

.table {
    color: var(--text);
    --bs-table-bg: transparent;
}

.table thead th {
    color: var(--text);
    border-color: var(--border);
}

.table td,
.table th {
    border-color: var(--border);
}

.pagination .page-link {
    background: var(--card);
    color: var(--text);
    border-color: var(--border);
}

.pagination .page-link:hover {
    background: var(--border);
    color: var(--text);
}

.pagination .page-item.active .page-link {
    background: var(--primary);
    border-color: var(--primary);
    color: #fff;
}

.pagination .page-item.disabled .page-link {
    background: var(--card);
    color: var(--muted);
}

.footer {
    background: var(--card);
    border-top: 1px solid var(--border);
    padding: 1.5rem 0;
    margin-top: auto;
    color: var(--muted);
}

.theme-toggle {
    cursor: pointer;
}

.search-hero .form-control {
    background: #fff;
    color: #212529;
}

.badge-status-pending {
    background: #ffc107;
    color: #000;
}

.badge-status-approved {
    background: #0a58ca;
    color: #fff;
}

.badge-status-borrowed {
    background: #3B82F6;
    color: #fff;
}

.badge-status-returned {
    background: #198754;
    color: #fff;
}

.badge-status-rejected {
    background: #dc3545;
    color: #fff;
}

.badge-status-overdue {
    background: #fd7e14;
    color: #fff;
}

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

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

.btn-outline-primary {
    color: var(--primary);
    border-color: var(--primary);
}

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

.alert {
    color: var(--text);
}

[data-theme="dark"] .btn-close {
    filter: invert(1);
}

.report-table th,
.report-table td {
    vertical-align: middle;
}

.penalty-notice {
    max-width: 800px;
    margin: 0 auto;
}

.penalty-meta-table th {
    width: 40%;
    font-weight: 600;
    white-space: nowrap;
}

.penalty-instructions {
    background: var(--surface-elevated, #f8f9fa);
    border-radius: 0.375rem;
}

.signature-line {
    border-bottom: 1px solid var(--border, #dee2e6);
    height: 40px;
    margin-bottom: 4px;
}

.favorite-category-option {
    cursor: pointer;
    background: var(--card);
    transition: border-color 0.2s, background 0.2s;
}

.favorite-category-option:has(input:checked) {
    border-color: var(--primary) !important;
    background: rgba(var(--primary-rgb), 0.08);
}

@media print {
    body {
        background: #fff;
        color: #000;
        display: block;
    }

    .site-navbar,
    .footer,
    .theme-toggle,
    .no-print,
    .btn,
    .nav,
    .pagination,
    .alert {
        display: none !important;
    }

    main.main-content,
    .container,
    .table-responsive {
        padding: 0 !important;
        margin: 0 !important;
        max-width: 100% !important;
        overflow: visible !important;
    }

    .print-header,
    .print-report,
    .card,
    .table,
    .table th,
    .table td,
    .text-muted,
    small.text-muted {
        color: #000 !important;
        background: #fff !important;
        box-shadow: none !important;
    }

    .print-report {
        font-size: 12px;
    }

    .report-table {
        width: 100%;
        border-collapse: collapse;
    }

    .report-table th,
    .report-table td {
        border: 1px solid #000 !important;
        padding: 6px !important;
    }

    .report-table thead {
        display: table-header-group;
    }

    .stat-card {
        border: 1px solid #000 !important;
        break-inside: avoid;
    }

    tr,
    img {
        page-break-inside: avoid;
    }

    .penalty-notice {
        max-width: 800px;
        margin: 0 auto;
    }

    .penalty-notice-header h3,
    .penalty-notice-header h4 {
        color: #000 !important;
    }

    .penalty-meta-table th {
        width: 40%;
        font-weight: 600;
        padding: 2px 8px 2px 0 !important;
    }

    .penalty-meta-table td {
        padding: 2px 0 !important;
    }

    .penalty-instructions {
        border: 1px solid #000 !important;
        break-inside: avoid;
    }

    .signature-line {
        border-bottom: 1px solid #000;
        height: 40px;
        margin-bottom: 4px;
    }

    .badge {
        border: 1px solid #000 !important;
        color: #000 !important;
        background: #fff !important;
    }
}

@media (max-width: 768px) {
    .hero-section {
        padding: 2rem 0;
    }

    .stat-card .stat-value {
        font-size: 1.5rem;
    }
}

/* Error-prevention confirmation dialog */
.confirm-modal .modal-header {
    align-items: flex-start;
}

.confirm-modal-icon {
    font-size: 1.25rem;
    line-height: 1;
}

.confirm-modal-detail {
    background: var(--bg);
    color: var(--text);
}

[data-theme="dark"] .confirm-modal-detail {
    background: var(--input-bg);
}

.confirm-modal .modal-footer .btn {
    min-width: 6.5rem;
}

/* Visually separate destructive actions from primary ones in action rows */
td .btn-outline-danger,
td .btn-danger {
    margin-left: 0.15rem;
}

/* Card catalog */
.catalog-book-card {
    border: 1px solid rgba(var(--primary-rgb), 0.12);
    transition: transform 0.15s ease, box-shadow 0.15s ease;
}

.catalog-book-card:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 20px rgba(0, 0, 0, 0.08);
}

.catalog-card-title {
    font-size: 1.05rem;
    line-height: 1.35;
}

.catalog-meta {
    display: grid;
    gap: 0.25rem;
}

.catalog-meta > div {
    display: grid;
    grid-template-columns: 5.5rem 1fr;
    gap: 0.35rem;
}

.catalog-meta dt {
    margin: 0;
    color: var(--muted);
    font-weight: 500;
}

.catalog-meta dd {
    margin: 0;
}

.digital-resource-card,
.rule-stat-card {
    border: 1px solid rgba(var(--primary-rgb), 0.12);
}

.library-rules-content h5 {
    margin-top: 1.25rem;
    margin-bottom: 0.5rem;
}

.library-rules-content ul {
    padding-left: 1.2rem;
}

.status-pill,
.badge {
    font-weight: 600;
}

@media (max-width: 576px) {
    .catalog-meta > div {
        grid-template-columns: 1fr;
    }

    .brand-subtitle {
        display: none;
    }
}

/* ---------------------------------------------
   In-browser digital resource reader
   --------------------------------------------- */
.reader-frame {
    width: 100%;
    height: 82vh;
    border: 1px solid var(--bs-border-color);
    border-radius: 0.5rem;
    background: #fff;
}

.reader-shell {
    height: 82vh;
    display: flex;
    flex-direction: column;
}

.reader-epub-viewer {
    flex: 1 1 auto;
    overflow: hidden;
    background: #fff;
}

.reader-toolbar {
    background: rgba(var(--primary-rgb), 0.06);
}