/* ==========================================================================
   KRİPTOQRAFİYA KURSU - MODERN STİL DİZAYNI (style.css)
   Sleek Academic & Tech Light Theme | Fully Responsive
   ========================================================================== */

/* 1. CSS VARIABLES & LIGHT THEME */
:root {
    color-scheme: light;

    /* Theme colors - Pure Academic Light Mode */
    --bg-primary: #f8fafc;
    --bg-surface: #ffffff;
    --bg-sidebar: #f1f5f9;
    --bg-card: #ffffff;
    --bg-accent-subtle: #e0f2fe;

    --text-primary: #0f172a;
    --text-secondary: #334155;
    --text-muted: #64748b;
    --text-heading: #0f172a;

    --accent-primary: #0284c7;
    --accent-hover: #0369a1;
    --accent-teal: #0d9488;
    --accent-purple: #7c3aed;
    --accent-amber: #d97706;

    --border-color: #e2e8f0;
    --border-strong: #cbd5e1;

    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);

    --radius-sm: 6px;
    --radius-md: 10px;
    --radius-lg: 16px;

    --font-serif: 'Georgia', 'Times New Roman', serif;
    --font-sans: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --font-mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
}

/* 2. BASE RESET & SCROLL */
*, *::before, *::after {
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    scroll-padding-top: 80px;
    overflow-x: hidden;
}

body {
    font-family: var(--font-sans);
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.75;
    margin: 0;
    padding: 0;
    overflow-x: hidden;
    transition: background-color 0.25s ease, color 0.25s ease;
}

/* Target Section Highlight Effect */
.highlight-target {
    animation: targetHighlight 2s ease-out;
}
@keyframes targetHighlight {
    0% { background-color: rgba(56, 189, 248, 0.25); }
    100% { background-color: transparent; }
}

/* Reading Progress Bar */
#progress-bar {
    position: fixed;
    top: 0;
    left: 0;
    height: 3.5px;
    background: linear-gradient(90deg, var(--accent-primary), var(--accent-teal), var(--accent-purple));
    width: 0%;
    z-index: 1100;
    transition: width 0.1s linear;
}

/* 3. HEADER & NAVBAR */
.app-header {
    position: sticky;
    top: 0;
    z-index: 1040;
    background-color: rgba(255, 255, 255, 0.94);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border-color);
    transition: background-color 0.25s ease, border-color 0.25s ease;
}



.header-grid {
    display: grid;
    grid-template-columns: 1fr auto 1fr;
    align-items: center;
    gap: 12px;
}

.header-left {
    justify-self: start;
}

.header-center {
    justify-self: center;
}

.header-right {
    justify-self: end;
}

.brand-logo {
    font-weight: 800;
    font-size: 1.25rem;
    letter-spacing: -0.02em;
    color: var(--text-heading);
    display: inline-flex;
    align-items: center;
    gap: 8px;
    text-decoration: none;
    white-space: nowrap;
}

.brand-badge {
    font-size: 0.7rem;
    font-weight: 700;
    padding: 2px 7px;
    border-radius: 20px;
    background: linear-gradient(135deg, var(--accent-primary), var(--accent-teal));
    color: white;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.nav-link-custom {
    color: var(--text-secondary);
    font-weight: 600;
    font-size: 0.92rem;
    padding: 8px 12px;
    border-radius: var(--radius-sm);
    transition: all 0.2s ease;
    text-decoration: none;
    white-space: nowrap;
}

.nav-link-custom:hover {
    color: var(--accent-primary);
    background-color: var(--bg-sidebar);
}

.nav-link-custom.active {
    color: var(--accent-primary);
    background-color: var(--bg-accent-subtle);
}

/* Mobile Quick Navigation Strip */
.mobile-nav-strip {
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
    scrollbar-width: none;
    -ms-overflow-style: none;
}

.mobile-nav-strip::-webkit-scrollbar {
    display: none;
}

.mobile-nav-item {
    font-size: 0.8rem;
    font-weight: 600;
    color: var(--text-secondary);
    padding: 4px 10px;
    border-radius: 20px;
    background-color: var(--bg-sidebar);
    border: 1px solid var(--border-color);
    white-space: nowrap;
    text-decoration: none !important;
    transition: all 0.15s ease;
    display: inline-flex;
    align-items: center;
    flex-shrink: 0;
}

.mobile-nav-item:hover,
.mobile-nav-item.active {
    color: var(--accent-primary) !important;
    background-color: var(--bg-accent-subtle) !important;
    border-color: rgba(2, 132, 199, 0.3) !important;
}

/* Global Search Input */
.search-box {
    position: relative;
    max-width: 240px;
    width: 100%;
}

.search-input {
    width: 100%;
    padding: 6px 12px 6px 34px;
    border-radius: 20px;
    border: 1px solid var(--border-color);
    background-color: var(--bg-primary);
    color: var(--text-primary);
    font-size: 0.85rem;
    transition: all 0.2s ease;
}

.search-input:focus {
    outline: none;
    border-color: var(--accent-primary);
    box-shadow: 0 0 0 3px rgba(2, 132, 199, 0.15);
}

.search-icon {
    position: absolute;
    left: 10px;
    top: 50%;
    transform: translateY(-50%);
    color: var(--text-muted);
    font-size: 0.85rem;
    pointer-events: none;
}



/* 4. LAYOUT GRID & SIDEBAR */
.app-container {
    display: flex;
    min-height: calc(100vh - 65px);
    width: 100%;
    position: relative;
}

.app-sidebar {
    width: 325px;
    flex-shrink: 0;
    background-color: var(--bg-sidebar);
    border-right: 1px solid var(--border-color);
    position: sticky;
    top: 65px;
    height: calc(100vh - 65px);
    overflow-y: auto;
    padding: 1.25rem 0.85rem;
    transition: width 0.3s cubic-bezier(0.4, 0, 0.2, 1),
                padding 0.3s ease,
                opacity 0.25s ease,
                transform 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    z-index: 1040;
}

/* Sidebar Desktop / Universal Collapsed State */
body.sidebar-collapsed .app-sidebar {
    width: 0 !important;
    padding-left: 0 !important;
    padding-right: 0 !important;
    opacity: 0 !important;
    overflow: hidden !important;
    border-right: none !important;
    pointer-events: none !important;
}

body.sidebar-collapsed .app-main {
    max-width: 1100px;
    width: 100%;
}

/* Mobile Sidebar Backdrop Overlay */
.sidebar-backdrop {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    background-color: rgba(15, 23, 42, 0.5);
    backdrop-filter: blur(4px);
    z-index: 1030;
    opacity: 0;
    transition: opacity 0.25s ease;
}

.sidebar-backdrop.active {
    display: block;
    opacity: 1;
}

.toc-title {
    font-size: 0.78rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--text-muted);
    margin-bottom: 0.75rem;
    padding-bottom: 0.5rem;
    border-bottom: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.toc-list {
    list-style: none;
    padding: 0;
    margin: 0;
}

.toc-item {
    margin-bottom: 2px;
}

.toc-link {
    display: block;
    padding: 6px 10px;
    border-radius: var(--radius-sm);
    color: var(--text-secondary);
    font-size: 0.88rem;
    font-weight: 500;
    text-decoration: none;
    transition: all 0.15s ease;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.toc-link:hover {
    color: var(--accent-primary);
    background-color: rgba(2, 132, 199, 0.08);
}

.toc-link.active {
    color: var(--accent-primary);
    font-weight: 700;
    background-color: var(--bg-accent-subtle);
    border-left: 3px solid var(--accent-primary);
}

/* Collapsible TOC Tree & Toggle Arrows (180 deg rotation) */
li.has-sublist > .toc-link,
.toc-header-link {
    display: flex !important;
    align-items: center !important;
    justify-content: space-between !important;
    gap: 8px !important;
    padding: 7px 10px !important;
    cursor: pointer !important;
    user-select: none !important;
    text-decoration: none !important;
    overflow: visible !important; /* CRITICAL: Never clip or hide the toggle arrow */
    white-space: nowrap !important;
    width: 100% !important;
    box-sizing: border-box !important;
}

li.has-sublist > .toc-link > span:first-child,
.toc-header-link > span:first-child {
    flex: 1 1 auto !important;
    min-width: 0 !important;
    overflow: hidden !important;
    text-overflow: ellipsis !important;
    white-space: nowrap !important;
    display: inline-flex !important;
    align-items: center !important;
    font-size: 0.88rem !important;
}

.toc-toggle-icon {
    display: inline-flex !important;
    align-items: center !important;
    justify-content: center !important;
    width: 24px !important;
    height: 24px !important;
    min-width: 24px !important;
    max-width: 24px !important;
    border-radius: 6px;
    font-size: 0.82rem;
    color: var(--text-muted);
    transition: transform 0.28s cubic-bezier(0.4, 0, 0.2, 1), background-color 0.15s ease, color 0.15s ease;
    margin-left: auto !important;
    flex-shrink: 0 !important;
    flex-grow: 0 !important;
    transform: rotate(0deg);
}

.toc-header-link:hover .toc-toggle-icon,
.toc-link:hover .toc-toggle-icon {
    background-color: rgba(2, 132, 199, 0.12);
    color: var(--accent-primary);
}

/* 180 DEGREE ROTATION ON TOGGLE */
.toc-link.collapsed .toc-toggle-icon,
.toc-link[aria-expanded="false"] .toc-toggle-icon,
.toc-header-link.collapsed .toc-toggle-icon,
.toc-header-link[aria-expanded="false"] .toc-toggle-icon {
    transform: rotate(180deg) !important;
}

.toc-link:not(.collapsed) .toc-toggle-icon,
.toc-link[aria-expanded="true"] .toc-toggle-icon,
.toc-header-link:not(.collapsed) .toc-toggle-icon,
.toc-header-link[aria-expanded="true"] .toc-toggle-icon {
    transform: rotate(0deg) !important;
}

.toc-sublist {
    list-style: none;
    padding-left: 0.85rem;
    margin: 2px 0;
}

@keyframes fadeInToc {
    from {
        opacity: 0;
        transform: translateY(-4px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.toc-sublink {
    font-size: 0.82rem;
    padding: 4px 8px;
    color: var(--text-muted);
}

.app-main {
    flex-grow: 1;
    padding: 2rem;
    max-width: 960px;
    width: 100%;
    margin: 0 auto;
    overflow-x: hidden;
}

/* 5. TYPOGRAPHY & ACADEMIC STYLES */
.lecture-header {
    background: linear-gradient(135deg, var(--bg-card), var(--bg-sidebar));
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 2rem 1.5rem;
    margin-bottom: 2rem;
    box-shadow: var(--shadow-sm);
}

.lecture-title {
    font-size: 2.1rem;
    font-weight: 800;
    color: var(--text-heading);
    letter-spacing: -0.02em;
    margin-bottom: 0.5rem;
    word-break: break-word;
}

.lecture-subtitle {
    font-size: 1.15rem;
    color: var(--accent-primary);
    font-weight: 600;
    margin-bottom: 0.5rem;
}

h1, h2, h3, h4, h5, h6 {
    color: var(--text-heading);
    font-weight: 700;
    word-break: break-word;
}

h2 {
    font-size: 1.55rem;
    margin-top: 2.25rem;
    margin-bottom: 1.25rem;
    padding-bottom: 0.5rem;
    border-bottom: 2px solid var(--border-color);
}

h3 {
    font-size: 1.2rem;
    margin-top: 1.5rem;
    margin-bottom: 0.85rem;
    color: var(--accent-primary);
}

p, li, dd {
    font-size: 1rem;
    color: var(--text-primary);
    overflow-wrap: break-word;
}

/* Universal Underline Removal for All Links, Buttons, and Interactive Elements */
a,
a:hover,
a:focus,
a:active,
a:visited,
button,
button:hover,
button:focus,
button:active,
.brand-logo,
.brand-logo:hover,
.brand-logo:focus,
.brand-logo:active,
.nav-link,
.nav-link:hover,
.nav-link:focus,
.nav-link:active,
.nav-link-custom,
.nav-link-custom:hover,
.nav-link-custom:focus,
.nav-link-custom:active,
.toc-link,
.toc-link:hover,
.toc-link:focus,
.toc-link:active,
.btn,
.btn:hover,
.btn:focus,
.btn:active,
.catalog-card,
.catalog-card:hover,
.catalog-card:focus,
.catalog-card:active,
.catalog-card-link,
.catalog-card-link:hover,
.catalog-card-link:focus,
.catalog-card-link:active,
.citation-badge,
.citation-badge:hover,
.citation-badge:focus,
.citation-badge:active,
.search-result-item,
.search-result-item:hover,
.search-result-item:focus,
.search-result-item:active,
.bib-card,
.bib-card a,
.bib-card a:hover,
.bib-card a:focus,
.bib-card a:active {
    text-decoration: none !important;
}

a {
    color: var(--accent-primary);
    text-decoration: none !important;
    font-weight: 500;
    transition: color 0.15s ease;
    overflow-wrap: break-word;
}

a:hover,
a:focus,
a:active {
    color: var(--accent-hover);
    text-decoration: none !important;
}

/* Academic Callout Boxes & Cards */
.academic-box {
    border-radius: var(--radius-md);
    padding: 1.25rem;
    margin: 1.25rem 0;
    border-left: 5px solid var(--accent-primary);
    background-color: var(--bg-card);
    border-top: 1px solid var(--border-color);
    border-right: 1px solid var(--border-color);
    border-bottom: 1px solid var(--border-color);
    box-shadow: var(--shadow-sm);
    color: var(--text-primary);
}

.academic-box.box-note {
    border-left-color: var(--accent-primary);
    background-color: var(--bg-sidebar);
}

.academic-box.box-warning {
    border-left-color: #ef4444;
    background-color: rgba(239, 68, 68, 0.08);
}

.academic-box.box-tip {
    border-left-color: var(--accent-teal);
    background-color: rgba(13, 148, 136, 0.08);
}

.academic-box.box-keyconcept {
    border-left-color: var(--accent-amber);
    background-color: rgba(217, 119, 6, 0.08);
}

.definition-title {
    font-weight: 700;
    color: var(--accent-primary);
}

/* Code Badges & Blocks */
code {
    background-color: var(--bg-sidebar);
    color: var(--accent-primary);
    padding: 2px 6px;
    border-radius: 4px;
    font-family: var(--font-mono);
    font-size: 0.9em;
    border: 1px solid var(--border-color);
    word-break: break-all;
}

pre {
    background-color: var(--bg-sidebar);
    color: var(--text-primary);
    padding: 1rem;
    border-radius: var(--radius-sm);
    border: 1px solid var(--border-color);
    font-family: var(--font-mono);
    font-size: 0.9rem;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
    white-space: pre-wrap;
    word-break: break-all;
}

/* Collapsible Details & Summaries */
details {
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    margin-bottom: 1rem;
    overflow: hidden;
}

details summary {
    cursor: pointer;
    font-weight: 600;
    color: var(--text-heading);
    padding: 0.75rem 1rem;
    background-color: var(--bg-sidebar);
    transition: background-color 0.15s ease;
}

details summary:hover {
    background-color: var(--bg-accent-subtle);
    color: var(--accent-primary);
}

/* Tables Responsive Wrappers */
.table-responsive {
    width: 100%;
    margin: 1.25rem 0;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
    border-radius: var(--radius-sm);
    max-width: 100%;
}

table {
    width: 100%;
    border-collapse: collapse;
    color: var(--text-primary);
    max-width: 100%;
}

table th, table td {
    padding: 0.65rem 0.85rem;
    border: 1px solid var(--border-color);
    font-size: 0.92rem;
}

table th {
    background-color: var(--bg-sidebar);
    color: var(--text-heading);
    font-weight: 700;
}

/* MathJax and LaTeX Equation Responsive Containers */
.math-display,
.mathjax-container {
    display: block;
    text-align: center;
    overflow-x: auto;
    overflow-y: hidden;
    -webkit-overflow-scrolling: touch;
    padding: 0.5rem 0;
    margin: 0.85rem 0;
    max-width: 100%;
    color: var(--text-primary);
}

mjx-container[display="true"],
mjx-container[jax="CHTML"][display="true"] {
    display: block !important;
    text-align: center !important;
    margin: 0.75rem auto !important;
    max-width: 100% !important;
    overflow-x: auto !important;
    overflow-y: hidden !important;
}

mjx-container:not([display="true"]),
mjx-container[jax="CHTML"]:not([display="true"]) {
    display: inline-block;
    margin: 0 0.08em !important;
    padding: 0 !important;
    max-width: 100%;
}

span.math.inline,
.math.inline {
    display: inline;
    white-space: nowrap;
    vertical-align: baseline;
}

/* Canvas Diagram Responsive Wrapper */
.canvas-container {
    width: 100%;
    max-width: 600px;
    overflow-x: auto;
    margin: 0 auto;
    -webkit-overflow-scrolling: touch;
}

canvas {
    max-width: 100%;
    height: auto;
}

/* 6. OVERRIDE BOOTSTRAP UTILITY CLASSES FOR THEME COMPATIBILITY */
.bg-light, .bg-white {
    background-color: var(--bg-card) !important;
    color: var(--text-primary) !important;
}

.text-dark {
    color: var(--text-heading) !important;
}

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

.card {
    background-color: var(--bg-card) !important;
    border-color: var(--border-color) !important;
    color: var(--text-primary) !important;
}

.card-title, .card-text {
    color: var(--text-primary) !important;
}

.table-light, .table-light th, .table-light td {
    background-color: var(--bg-sidebar) !important;
    color: var(--text-heading) !important;
    border-color: var(--border-color) !important;
}

/* 7. INTERACTIVE TOOLS VIEW */
.tool-card {
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 1.5rem;
    margin-bottom: 2rem;
    box-shadow: var(--shadow-md);
}

.tool-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-bottom: 1.25rem;
    padding-bottom: 0.75rem;
    border-bottom: 1px solid var(--border-color);
}

.tool-title {
    font-size: 1.25rem;
    font-weight: 700;
    margin: 0;
    display: flex;
    align-items: center;
    gap: 8px;
}

.tool-control-group {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
    gap: 1rem;
    margin-bottom: 1.25rem;
}

.form-label-custom {
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--text-secondary);
    margin-bottom: 0.35rem;
    display: block;
}

.form-input-custom, .form-select-custom {
    padding: 8px 12px;
    border-radius: var(--radius-sm);
    border: 1px solid var(--border-color);
    background-color: var(--bg-primary);
    color: var(--text-primary);
    font-size: 0.92rem;
    font-family: var(--font-sans);
    width: 100%;
}

.form-input-custom:focus {
    outline: none;
    border-color: var(--accent-primary);
}

.tool-output-box {
    background-color: var(--bg-sidebar);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    padding: 1rem;
    font-family: var(--font-mono);
    font-size: 1rem;
    color: var(--accent-primary);
    word-break: break-all;
    min-height: 50px;
    margin-top: 0.5rem;
}

/* Frequency Bar Chart Visualization */
.freq-chart-container {
    display: flex;
    align-items: flex-end;
    gap: 3px;
    height: 170px;
    padding: 1rem 0;
    border-bottom: 1px solid var(--border-color);
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
}

.freq-bar-wrapper {
    flex: 1;
    min-width: 16px;
    display: flex;
    flex-direction: column;
    align-items: center;
    height: 100%;
    justify-content: flex-end;
}

.freq-bar {
    width: 100%;
    background: linear-gradient(180deg, var(--accent-primary), var(--accent-teal));
    border-radius: 3px 3px 0 0;
    transition: height 0.3s ease;
}

.freq-label {
    font-size: 0.7rem;
    font-weight: 600;
    margin-top: 4px;
    color: var(--text-secondary);
}

/* 8. QUIZ / PRACTICE VIEW */
.quiz-card {
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 1.25rem;
    margin-bottom: 1.25rem;
    box-shadow: var(--shadow-sm);
}

.quiz-option {
    display: flex;
    align-items: center;
    padding: 10px 14px;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    margin-bottom: 8px;
    cursor: pointer;
    transition: all 0.15s ease;
    color: var(--text-primary);
    font-size: 0.92rem;
}

.quiz-option:hover {
    background-color: var(--bg-sidebar);
    border-color: var(--accent-primary);
}

.quiz-option.correct {
    background-color: rgba(13, 148, 136, 0.15);
    border-color: var(--accent-teal);
    color: var(--accent-teal);
    font-weight: 600;
}

.quiz-option.incorrect {
    background-color: rgba(239, 68, 68, 0.15);
    border-color: #ef4444;
    color: #ef4444;
}

/* ==========================================================================
   9. COMPREHENSIVE RESPONSIVE DESIGN SYSTEM (ALL SCREENS & DEVICES)
   ========================================================================== */

/* 1. Ultra-Wide, 2K & 4K Displays (1400px - 2560px+) */
@media (min-width: 1400px) {
    .app-sidebar {
        width: 330px;
    }
    .lecture-content-viewport,
    .catalog-view,
    #view-tools,
    #view-quiz,
    #view-bib {
        max-width: 1280px;
        margin-left: auto;
        margin-right: auto;
    }
    .search-box {
        max-width: 280px;
    }
}

@media (min-width: 1800px) {
    .app-sidebar {
        width: 340px;
    }
    .lecture-content-viewport,
    .catalog-view,
    #view-tools,
    #view-quiz,
    #view-bib {
        max-width: 1440px;
    }
    body {
        font-size: 1.05rem;
    }
}

/* 2. Standard Tablets & Desktops (Below 1200px) */
@media (max-width: 1200px) {
    .app-main {
        padding: 2rem 1.75rem;
    }
    .search-box {
        max-width: 200px;
    }
    .nav-link-custom {
        padding: 6px 10px;
        font-size: 0.88rem;
    }
}

/* 3. Tablets in Portrait & Small Laptops (max-width: 992px) */
@media (max-width: 992px) {
    .app-sidebar {
        position: fixed;
        left: 0;
        top: 0;
        height: 100vh;
        width: min(320px, 85vw);
        transform: translateX(-100%);
        box-shadow: 0 0 40px rgba(0, 0, 0, 0.25);
        z-index: 1050;
        padding-top: 1rem;
    }

    .app-sidebar.open {
        transform: translateX(0);
    }

    .app-main {
        padding: 1.5rem 1.25rem;
        width: 100%;
        max-width: 100%;
    }

    .lecture-header {
        padding: 1.5rem 1.25rem;
    }

    .lecture-title {
        font-size: 1.65rem;
    }

    .search-box {
        max-width: 160px;
    }

    .header-grid {
        gap: 8px;
    }
}

/* 4. Large Smartphones & Phablets (max-width: 768px) */
@media (max-width: 768px) {
    .header-grid {
        grid-template-columns: auto 1fr auto;
        gap: 6px;
    }

    .brand-logo {
        font-size: 1.05rem;
        gap: 6px;
    }

    .brand-badge {
        font-size: 0.65rem;
        padding: 2px 6px;
    }

    .app-main {
        padding: 1.25rem 0.85rem;
    }

    .lecture-title {
        font-size: 1.45rem;
        line-height: 1.35;
    }

    .lecture-header {
        padding: 1.25rem 1rem;
        margin-bottom: 1.5rem;
    }

    .tool-control-group {
        grid-template-columns: 1fr;
        gap: 0.85rem;
    }

    .tool-card {
        padding: 1.15rem;
        margin-bottom: 1.5rem;
    }

    .tool-title {
        font-size: 1.1rem;
    }

    .academic-box, .note, .definition, .theorem, .proof, .example, .warning {
        padding: 1rem 0.85rem;
        margin: 1rem 0;
        font-size: 0.95rem;
    }

    .titlepage {
        padding: 1.5rem 1rem;
        margin-bottom: 1.5rem;
    }

    .titlepage p strong {
        font-size: 1.35rem;
    }

    .search-box {
        max-width: 140px;
    }

    .search-input {
        font-size: 0.8rem;
        padding: 5px 10px 5px 28px;
    }

    .search-icon {
        font-size: 0.75rem;
        left: 8px;
    }

    /* Buttons & Form controls touch targets */
    .btn, button, input, select, textarea {
        min-height: 40px;
    }

    input, select, textarea {
        font-size: 16px !important; /* Prevents auto-zoom on iOS Safari */
    }

    /* Table horizontal touch scroll */
    .table-responsive, table {
        display: block;
        width: 100%;
        overflow-x: auto;
        -webkit-overflow-scrolling: touch;
    }

    table th, table td {
        padding: 0.5rem 0.65rem;
        font-size: 0.85rem;
        white-space: nowrap;
    }

    .lecture-nav-footer {
        flex-direction: column;
        gap: 0.75rem;
    }

    .lecture-nav-btn, .lecture-nav-catalog-btn {
        width: 100%;
        flex: none;
    }
}

/* 5. Standard & Compact Mobile Devices (max-width: 576px) */
@media (max-width: 576px) {
    .header-grid {
        grid-template-columns: auto 1fr auto;
    }

    .brand-logo {
        font-size: 0.95rem;
    }

    .brand-logo i {
        font-size: 1.1rem;
    }

    .brand-logo span:first-of-type {
        display: inline-block;
        max-width: 140px;
        overflow: hidden;
        text-overflow: ellipsis;
        white-space: nowrap;
    }

    .app-main {
        padding: 1rem 0.65rem;
    }

    .lecture-header {
        padding: 1rem 0.75rem;
        margin-bottom: 1.25rem;
    }

    .lecture-title {
        font-size: 1.3rem;
    }

    .quiz-card {
        padding: 1rem 0.75rem;
    }

    .quiz-option {
        padding: 8px 10px;
        font-size: 0.88rem;
    }

    .bib-card {
        padding: 1rem 0.85rem;
    }

    .bib-filter-btn {
        font-size: 0.78rem;
        padding: 4px 10px;
    }

    .search-box {
        max-width: 110px;
    }

    .search-input {
        padding: 4px 8px 4px 24px;
        font-size: 0.78rem;
    }

    /* Math display scroll indicator */
    .math-display, .mathjax-container, mjx-container[display="true"] {
        padding: 0.4rem 0 !important;
        margin: 0.6rem 0 !important;
        font-size: 90% !important;
    }
}

/* 6. Extra Small Screens (max-width: 380px) */
@media (max-width: 380px) {
    .brand-logo span:first-of-type {
        max-width: 105px;
    }
    .brand-badge {
        display: none;
    }
    .app-main {
        padding: 0.85rem 0.45rem;
    }
    .lecture-title {
        font-size: 1.2rem;
    }
    .search-box {
        max-width: 90px;
    }
}

/* 10. PANDOC GENERATED CONTENT & ACADEMIC CALLOUT MAPPINGS */
.titlepage {
    background: linear-gradient(135deg, var(--bg-card), var(--bg-sidebar));
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 2rem 1.5rem;
    margin-bottom: 2rem;
    box-shadow: var(--shadow-sm);
    text-align: center;
}

.titlepage p strong {
    font-size: 1.8rem;
    color: var(--text-heading);
}

.note, .definition, .history, .theorem, .proof, .example, .warning {
    border-radius: var(--radius-md);
    padding: 1.25rem;
    margin: 1.25rem 0;
    border-left: 5px solid var(--accent-primary);
    background-color: var(--bg-card);
    border-top: 1px solid var(--border-color);
    border-right: 1px solid var(--border-color);
    border-bottom: 1px solid var(--border-color);
    box-shadow: var(--shadow-sm);
    color: var(--text-primary);
}

.note, .definition {
    border-left-color: var(--accent-primary);
    background-color: var(--bg-sidebar);
}

.warning {
    border-left-color: #ef4444;
    background-color: rgba(239, 68, 68, 0.08);
}

.history, .example {
    border-left-color: var(--accent-teal);
    background-color: rgba(13, 148, 136, 0.08);
}

.theorem, .proof {
    border-left-color: var(--accent-amber);
    background-color: rgba(217, 119, 6, 0.08);
}

.note span, .definition span, .history span, .theorem span, .proof span, .example span, .warning span {
    display: block;
    font-weight: 700;
    color: var(--accent-primary);
    margin-bottom: 0.5rem;
    font-size: 1.05rem;
}

.citation:empty {
    display: none !important;
}

.bib-link {
    font-size: 0.82em;
    font-weight: 600;
    padding: 2px 7px;
    border-radius: 6px;
    background-color: var(--bg-accent-subtle);
    color: var(--accent-primary);
    border: 1px solid var(--border-color);
    text-decoration: none;
    transition: all 0.15s ease;
    display: inline-flex;
    align-items: center;
    gap: 3px;
    margin: 0 2px;
}

.bib-link:hover {
    background-color: var(--accent-primary);
    color: #ffffff;
    border-color: var(--accent-primary);
}

/* INTERACTIVE EXERCISE ACCORDION TOGGLES */
.accordion-toggle-head {
    cursor: pointer;
    user-select: none;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0.85rem 1.25rem;
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 10px;
    color: var(--text-main);
    font-size: 1.05rem;
    font-weight: 700;
    transition: all 0.2s ease;
    margin-top: 0.75rem;
    margin-bottom: 0.5rem;
    box-shadow: 0 2px 6px rgba(0, 0, 0, 0.15);
}

.accordion-toggle-head:hover {
    background-color: var(--bg-hover);
    border-color: var(--accent-primary);
}

.accordion-toggle-head.active-accordion {
    background-color: var(--bg-hover);
    border-color: var(--accent-primary);
}

.accordion-toggle-head .toggle-icon {
    color: var(--text-muted);
    transition: transform 0.2s ease;
}

.accordion-answer-body {
    display: none;
    padding: 0.85rem 1.15rem 1.15rem 1.15rem;
    border-left: 2px dashed var(--border-color);
    margin-left: 0.75rem;
    margin-bottom: 1rem;
    transition: all 0.25s ease-in-out;
}

.center {
    display: flex;
    justify-content: center;
    overflow-x: auto;
    margin: 1.25rem 0;
}

.highlight-target {
    animation: highlightPulse 2s ease;
}

@keyframes highlightPulse {
    0% { background-color: rgba(2, 132, 199, 0.25); }
    100% { background-color: transparent; }
}

.catalog-hero {
    background: linear-gradient(135deg, #e0f2fe 0%, #f0f9ff 50%, #f8fafc 100%);
    border: 1px solid var(--border-color);
    position: relative;
    overflow: hidden;
    color: var(--text-primary);
}



.stat-card {
    background-color: var(--bg-card);
    border: 1px solid var(--border-color) !important;
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.stat-card:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md) !important;
}

.catalog-card {
    background-color: var(--bg-card);
    border: 1px solid var(--border-color) !important;
    border-radius: 14px;
    transition: transform 0.25s ease, box-shadow 0.25s ease, border-color 0.25s ease;
}

.catalog-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg) !important;
    border-color: var(--accent-primary) !important;
}

.catalog-card .card-title {
    color: var(--text-primary);
    font-size: 1.1rem;
    line-height: 1.35;
}

.catalog-card .card-text {
    color: var(--text-secondary) !important;
    line-height: 1.5;
}

.opacity-90 {
    opacity: 0.9;
}

/* Search Dropdown Styling */
.search-results-dropdown {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    margin-top: 6px;
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    box-shadow: var(--shadow-lg);
    z-index: 1050;
    max-height: 380px;
    overflow-y: auto;
    display: none;
}

.search-result-item {
    border-bottom: 1px solid var(--border-color);
    transition: background-color 0.15s ease;
}

.search-result-item:hover {
    background-color: var(--bg-hover);
}





/* COMFORTABLE EYE-FRIENDLY CARD HEADERS (NO HARSH BLUE BACKGROUNDS) */
.card-header {
    background-color: var(--bg-card) !important;
    border-bottom: 1px solid var(--border-color) !important;
    color: var(--text-main) !important;
    font-weight: 700 !important;
}

.card-header.bg-primary,
.card-header.bg-teal,
.card-header.bg-purple,
.card-header.bg-warning {
    background-color: var(--bg-card) !important;
    color: var(--text-main) !important;
    border-bottom: 1px solid var(--border-color) !important;
}

/* Color Palette & Custom Utility Classes */
.text-teal {
    color: #0d9488 !important;
}
.bg-teal {
    background-color: #0d9488 !important;
    color: #ffffff !important;
}
.bg-teal-subtle {
    background-color: #ccfbf1 !important;
    color: #0d9488 !important;
}

.text-purple {
    color: #7c3aed !important;
}
.bg-purple {
    background-color: #7c3aed !important;
    color: #ffffff !important;
}
.bg-purple-subtle {
    background-color: #ede9fe !important;
    color: #6d28d9 !important;
}
.badge.bg-purple-subtle {
    background-color: #ede9fe !important;
    color: #6d28d9 !important;
}
.btn-outline-purple {
    color: #7c3aed !important;
    border-color: #7c3aed !important;
    background-color: transparent !important;
}
.btn-outline-purple:hover,
.btn-outline-purple:focus,
.btn-outline-purple:active {
    color: #ffffff !important;
    background-color: #7c3aed !important;
    border-color: #7c3aed !important;
}
.btn-purple {
    color: #ffffff !important;
    background-color: #7c3aed !important;
    border-color: #7c3aed !important;
}

.text-amber {
    color: #d97706 !important;
}
.bg-amber {
    background-color: #d97706 !important;
    color: #ffffff !important;
}
.bg-amber-subtle {
    background-color: #fef3c7 !important;
    color: #92400e !important;
}

/* ==========================================================================
   RESPONSIVE LECTURE NAVIGATION FOOTER (ƏVVƏLKİ / NÖVBƏTİ MÜHAZİRƏ)
   ========================================================================== */
.lecture-nav-footer {
    display: flex;
    align-items: stretch;
    justify-content: space-between;
    gap: 1rem;
    margin-top: 3.5rem;
    padding-top: 2rem;
    padding-bottom: 2rem;
    border-top: 2px solid var(--border-color);
}

.lecture-nav-btn {
    display: flex;
    align-items: center;
    gap: 0.85rem;
    padding: 0.95rem 1.25rem;
    border-radius: var(--radius-md);
    text-decoration: none !important;
    transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
    flex: 1;
    min-width: 0;
    box-shadow: var(--shadow-sm);
}

.lecture-nav-btn.prev-btn {
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    color: var(--text-heading);
    justify-content: flex-start;
}

.lecture-nav-btn.prev-btn:hover {
    border-color: var(--accent-primary);
    background-color: var(--bg-sidebar);
    transform: translateX(-4px);
    box-shadow: var(--shadow-md);
}

.lecture-nav-btn.next-btn {
    background: linear-gradient(135deg, var(--accent-primary), var(--accent-hover));
    border: 1px solid var(--accent-primary);
    color: #ffffff !important;
    justify-content: flex-end;
    text-align: right;
}

.lecture-nav-btn.next-btn:hover {
    background: linear-gradient(135deg, var(--accent-hover), #0369a1);
    border-color: var(--accent-hover);
    transform: translateX(4px);
    box-shadow: 0 6px 16px rgba(2, 132, 199, 0.35);
}

.lecture-nav-btn .nav-direction {
    font-size: 0.72rem;
    text-transform: uppercase;
    letter-spacing: 0.06em;
    font-weight: 700;
    margin-bottom: 2px;
}

.lecture-nav-btn.prev-btn .nav-direction {
    color: var(--text-muted);
}

.lecture-nav-btn.next-btn .nav-direction {
    color: rgba(255, 255, 255, 0.85);
}

.lecture-nav-btn .nav-title {
    font-size: 0.95rem;
    font-weight: 700;
    line-height: 1.35;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.lecture-nav-catalog-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 0.95rem 1.25rem;
    border-radius: var(--radius-md);
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    color: var(--text-secondary);
    font-weight: 600;
    text-decoration: none !important;
    transition: all 0.2s ease;
    flex-shrink: 0;
}

.lecture-nav-catalog-btn:hover {
    background-color: var(--bg-sidebar);
    color: var(--accent-primary);
    border-color: var(--accent-primary);
}

/* Fluid Typography & Clean Paragraphs (No Awkward Single-Word Breaks) */
p, li, dd {
    font-size: 1.025rem;
    line-height: 1.75;
    color: var(--text-primary);
    margin-bottom: 1.15rem;
    overflow-wrap: break-word;
    word-break: normal;
    text-wrap: pretty;
}



@media (max-width: 768px) {
    .lecture-nav-footer {
        flex-direction: column;
        gap: 0.75rem;
    }
    .lecture-nav-btn {
        width: 100%;
        flex: none;
    }
    .lecture-nav-btn.next-btn {
        order: -1; /* Make next lecture button top on mobile for fluid progression */
        justify-content: space-between;
        text-align: left;
    }
    .lecture-nav-btn.prev-btn {
        justify-content: flex-start;
    }
    .lecture-nav-catalog-btn {
        width: 100%;
        order: 1;
    }
}

/* ==========================================================================
   ACADEMIC CITATION ENGINE & MASTER BIBLIOGRAPHY STYLES
   ========================================================================== */

/* Inline Citation Badges */
.citation-ref-badge {
    display: inline-flex;
    align-items: baseline;
    padding: 0.08em 0.45em;
    margin: 0 0.15em;
    font-size: 0.88em;
    font-weight: 600;
    color: var(--accent-primary) !important;
    background-color: var(--bg-accent-subtle);
    border: 1px solid rgba(2, 132, 199, 0.25);
    border-radius: 4px;
    text-decoration: none !important;
    transition: all 0.15s ease;
    cursor: pointer;
    vertical-align: baseline;
    white-space: nowrap;
}

.citation-ref-badge:hover {
    background-color: var(--accent-primary);
    color: #ffffff !important;
    box-shadow: 0 2px 4px rgba(2, 132, 199, 0.2);
    transform: translateY(-1px);
}

/* Popover Content Styling */
.popover {
    border: 1px solid var(--border-color) !important;
    box-shadow: var(--shadow-lg) !important;
    border-radius: var(--radius-md) !important;
    max-width: 320px !important;
    z-index: 1060;
}

.popover-header {
    background-color: var(--bg-sidebar) !important;
    color: var(--accent-primary) !important;
    font-weight: 700 !important;
    font-size: 0.85rem !important;
    border-bottom: 1px solid var(--border-color) !important;
    padding: 0.6rem 0.85rem !important;
}

.popover-body {
    padding: 0.75rem 0.85rem !important;
    font-size: 0.84rem !important;
    color: var(--text-primary) !important;
    line-height: 1.5 !important;
}

/* Lecture Bibliography Section */
.lecture-bib-section {
    margin-top: 3rem;
    padding: 1.75rem;
    background-color: #ffffff;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
}

.lecture-bib-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding-bottom: 1rem;
    margin-bottom: 1.25rem;
    border-bottom: 2px solid var(--bg-accent-subtle);
    flex-wrap: wrap;
    gap: 0.75rem;
}

.lecture-bib-item {
    padding: 1rem 1.25rem;
    margin-bottom: 0.85rem;
    background-color: var(--bg-primary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    transition: border-color 0.2s ease, box-shadow 0.2s ease, transform 0.2s ease;
}

.lecture-bib-item:hover {
    border-color: var(--accent-primary);
    background-color: #ffffff;
    box-shadow: var(--shadow-sm);
    transform: translateY(-1px);
}

/* Master Bibliography Library Page */
.bib-filter-btn {
    border-radius: 20px;
    padding: 6px 14px;
    font-size: 0.85rem;
    font-weight: 600;
    transition: all 0.2s ease;
}

.bib-card {
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 1.25rem;
    margin-bottom: 1rem;
    transition: all 0.2s ease;
    box-shadow: var(--shadow-sm);
    height: 100%;
    display: flex;
    flex-column: column;
    justify-content: space-between;
}

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

/* Toast Notifications */
.kripto-toast {
    position: fixed;
    bottom: 24px;
    right: 24px;
    background: #0f172a;
    color: #ffffff;
    padding: 10px 18px;
    border-radius: 8px;
    font-size: 0.88rem;
    font-weight: 600;
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.2);
    z-index: 9999;
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.25s ease, transform 0.25s ease;
    pointer-events: none;
    display: flex;
    align-items: center;
    gap: 8px;
}

.kripto-toast.show {
    opacity: 1;
    transform: translateY(0);
}

@media (max-width: 576px) {
    .kripto-toast {
        left: 16px !important;
        right: 16px !important;
        bottom: 16px !important;
        justify-content: center;
        text-align: center;
        max-width: calc(100vw - 32px);
    }
}

/* PWA Sync Button & Animation */
@keyframes kripto-spin {
    from { transform: rotate(0deg); }
    to { transform: rotate(360deg); }
}

.spin, .bi-arrow-repeat.spin {
    animation: kripto-spin 0.9s linear infinite !important;
    display: inline-block;
}

#btn-sync-app {
    background-color: var(--bg-card) !important;
    border: 1px solid var(--border-color) !important;
    transition: all 0.2s ease;
    cursor: pointer;
}

#btn-sync-app:hover {
    background-color: var(--bg-secondary) !important;
    border-color: var(--primary-color) !important;
    transform: translateY(-1px);
}

/* ==========================================================================
   11. ENTERPRISE OMNISEARCH (SPOTLIGHT / COMMAND PALETTE) STYLES
   ========================================================================== */

.search-trigger-btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 6px 12px;
    background-color: var(--bg-primary);
    border: 1px solid var(--border-color);
    border-radius: 20px;
    color: var(--text-muted);
    font-size: 0.85rem;
    cursor: pointer;
    transition: all 0.2s ease;
    white-space: nowrap;
}

.search-trigger-btn:hover {
    border-color: var(--accent-primary);
    color: var(--text-primary);
    background-color: var(--bg-card);
    box-shadow: var(--shadow-sm);
}

.search-kbd-badge {
    background-color: var(--bg-sidebar);
    border: 1px solid var(--border-color);
    border-radius: 4px;
    padding: 1px 5px;
    font-size: 0.72rem;
    font-weight: 700;
    color: var(--text-secondary);
    font-family: var(--font-mono);
}

/* Omnisearch Modal Overlay */
.omnisearch-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    background-color: rgba(15, 23, 42, 0.65);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    z-index: 2000;
    display: flex;
    align-items: flex-start;
    justify-content: center;
    padding: 4rem 1rem 2rem;
    opacity: 0;
    transition: opacity 0.2s ease;
}

.omnisearch-overlay.active {
    opacity: 1;
}

.omnisearch-dialog {
    width: 100%;
    max-width: 680px;
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.35);
    overflow: hidden;
    display: flex;
    flex-direction: column;
    max-height: 80vh;
    transform: scale(0.96) translateY(-10px);
    transition: transform 0.2s cubic-bezier(0.16, 1, 0.3, 1);
}

.omnisearch-overlay.active .omnisearch-dialog {
    transform: scale(1) translateY(0);
}

/* Header & Input */
.omnisearch-header {
    display: flex;
    align-items: center;
    padding: 1rem 1.25rem;
    border-bottom: 1px solid var(--border-color);
    background-color: var(--bg-card);
    gap: 12px;
}

.omnisearch-icon {
    font-size: 1.25rem;
    color: var(--accent-primary);
    flex-shrink: 0;
}

.omnisearch-input {
    flex: 1;
    border: none;
    background: transparent;
    font-size: 1.05rem;
    color: var(--text-primary);
    font-family: var(--font-sans);
    outline: none;
}

.omnisearch-input::placeholder {
    color: var(--text-muted);
}

.omnisearch-esc-badge {
    background-color: var(--bg-sidebar);
    border: 1px solid var(--border-color);
    border-radius: 4px;
    padding: 2px 6px;
    font-size: 0.72rem;
    color: var(--text-muted);
    font-weight: 700;
    cursor: pointer;
    flex-shrink: 0;
}

.btn-clear {
    background: none;
    border: none;
    color: var(--text-muted);
    font-size: 1rem;
    cursor: pointer;
    padding: 0;
    display: flex;
    align-items: center;
}

.btn-clear:hover {
    color: var(--text-primary);
}

/* Facet Filter Tabs */
.omnisearch-facets {
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 0.65rem 1.25rem;
    background-color: var(--bg-sidebar);
    border-bottom: 1px solid var(--border-color);
    overflow-x: auto;
    scrollbar-width: none;
    -webkit-overflow-scrolling: touch;
}

.omnisearch-facets::-webkit-scrollbar {
    display: none;
}

.facet-pill {
    padding: 4px 10px;
    border-radius: 20px;
    font-size: 0.78rem;
    font-weight: 600;
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    color: var(--text-secondary);
    cursor: pointer;
    white-space: nowrap;
    transition: all 0.15s ease;
}

.facet-pill:hover {
    border-color: var(--accent-primary);
    color: var(--accent-primary);
}

.facet-pill.active {
    background-color: var(--accent-primary);
    border-color: var(--accent-primary);
    color: #ffffff;
}

/* Suggestions & Quick Tags */
.omnisearch-suggestions {
    padding: 1.25rem;
    overflow-y: auto;
}

.suggestion-label {
    font-size: 0.75rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.06em;
    color: var(--text-muted);
    margin-bottom: 0.75rem;
}

.suggestion-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

.suggestion-tag {
    padding: 6px 12px;
    border-radius: var(--radius-sm);
    background-color: var(--bg-sidebar);
    border: 1px solid var(--border-color);
    color: var(--text-primary);
    font-size: 0.85rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.15s ease;
}

.suggestion-tag:hover {
    background-color: var(--bg-accent-subtle);
    border-color: rgba(2, 132, 199, 0.4);
    color: var(--accent-primary);
    transform: translateY(-1px);
}

/* Results List */
.omnisearch-results {
    overflow-y: auto;
    padding: 0.5rem 0;
    max-height: 50vh;
}

.search-result-item {
    display: flex;
    align-items: flex-start;
    gap: 12px;
    padding: 0.85rem 1.25rem;
    border-bottom: 1px solid rgba(0, 0, 0, 0.04);
    color: var(--text-primary);
    text-decoration: none !important;
    transition: background-color 0.12s ease;
    cursor: pointer;
}

.search-result-item:hover,
.search-result-item.selected {
    background-color: var(--bg-sidebar);
}

.search-result-icon {
    width: 32px;
    height: 32px;
    border-radius: 8px;
    background-color: var(--bg-accent-subtle);
    color: var(--accent-primary);
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font-size: 1rem;
    flex-shrink: 0;
    margin-top: 2px;
}

.search-result-body {
    flex: 1;
    min-width: 0;
}

.search-result-title {
    font-weight: 700;
    font-size: 0.95rem;
    color: var(--text-heading);
    margin-bottom: 2px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 8px;
}

.search-result-snippet {
    font-size: 0.82rem;
    color: var(--text-secondary);
    line-height: 1.4;
    overflow: hidden;
    text-overflow: ellipsis;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
}

.search-result-meta {
    font-size: 0.72rem;
    color: var(--text-muted);
    margin-top: 4px;
    display: flex;
    align-items: center;
    gap: 8px;
}

.search-highlight {
    background-color: rgba(253, 224, 71, 0.45);
    color: inherit;
    font-weight: 700;
    padding: 0.05em 0.2em;
    border-radius: 3px;
}

/* Footer */
.omnisearch-footer {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0.65rem 1.25rem;
    background-color: var(--bg-sidebar);
    border-top: 1px solid var(--border-color);
    font-size: 0.75rem;
}

.omnisearch-footer kbd {
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 3px;
    padding: 1px 4px;
    font-size: 0.68rem;
    margin-right: 4px;
    color: var(--text-primary);
}

.omnisearch-kbd {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    border-bottom-width: 2px;
    border-radius: 4px;
    padding: 2px 6px;
    font-size: 0.72rem;
    color: var(--text-primary);
    line-height: 1;
    min-width: 24px;
    box-shadow: 0 1px 0 var(--border-color);
}

.omnisearch-kbd i {
    font-size: 0.7rem;
}

/* Back to Top Floating Button */
.back-to-top-btn {
    position: fixed;
    bottom: 24px;
    left: 24px;
    width: 44px;
    height: 44px;
    border-radius: 50%;
    background-color: var(--accent-primary);
    color: #ffffff;
    border: none;
    box-shadow: 0 4px 12px rgba(2, 132, 199, 0.35);
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font-size: 1.15rem;
    cursor: pointer;
    z-index: 1020;
    opacity: 0;
    transform: translateY(16px);
    transition: opacity 0.25s ease, transform 0.25s ease, background-color 0.2s ease;
    pointer-events: none;
}

.back-to-top-btn.show {
    opacity: 1;
    transform: translateY(0);
    pointer-events: auto;
}

.back-to-top-btn:hover {
    background-color: var(--accent-hover);
    transform: translateY(-2px);
}

/* Hide redundant embedded Pandoc TOC in lecture documents (SPA has dedicated sidebar TOC) */
#TOC,
nav#TOC,
nav[role="doc-toc"],
.embedded-toc {
    display: none !important;
}






/* ==========================================================================
   MOBILE & TABLET RESPONSIVENESS (iOS, Android, iPad, Tablets)
   ========================================================================== */
.lecture-body table,
.content-body table,
#lecture-content-viewport table,
.markdown-body table {
    max-width: 100% !important;
    overflow-x: auto !important;
    display: block !important;
    -webkit-overflow-scrolling: touch;
}

#lecture-content-viewport pre,
#lecture-content-viewport code {
    max-width: 100%;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
}

mjx-container[display="true"] {
    -webkit-overflow-scrolling: touch !important;
}

/* PWA / Mobile Web App Shortcut Styles */
.sidebar-pwa-card {
    background: linear-gradient(135deg, #f8fafc, #f1f5f9);
    border: 1px solid #e2e8f0;
    box-shadow: var(--shadow-sm);
    transition: transform 0.18s ease, box-shadow 0.18s ease;
}

[data-theme="dark"] .sidebar-pwa-card {
    background: linear-gradient(135deg, #1e293b, #0f172a);
    border-color: #334155;
}

.sidebar-pwa-card:hover {
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

#btn-install-app {
    transition: all 0.2s ease;
    border-radius: 8px;
}

#btn-install-app:hover {
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(37, 99, 235, 0.2);
}