/* ============ Wikipedia/GitHub inspired design ============ */
:root {
    /* Primary Colors */
    --bg-color: #ffffff;
    --text-color: #24292e;
    --border-color: #e1e4e8;
    --link-color: #0366d6;
    --link-visited: #6f42c1;
    --link-hover: #005cc5;
    --sidebar-bg: #f6f8fa;
    --code-bg: #f6f8fa;
    --table-border: #dfe2e5;
    --table-header-bg: #f6f8fa;
    --blockquote-border: #dfe2e5;
    --muted-color: #6a737d;
    --accent-color: #0366d6;
    --shadow: 0 1px 3px rgba(0,0,0,0.12);
    --shadow-hover: 0 3px 12px rgba(0,0,0,0.15);

    /* GitHub-like Additional Colors */
    --success-color: #28a745;
    --warning-color: #ffd33d;
    --danger-color: #d73a49;
    --info-color: #0366d6;

    /* Spacing and Sizes */
    --border-radius: 6px;
    --border-radius-sm: 3px;
    --spacing-xs: 4px;
    --spacing-sm: 8px;
    --spacing-md: 16px;
    --spacing-lg: 24px;
    --spacing-xl: 32px;

    /* Note Colors */
    --note-bg: #f1f8ff;
    --warning-bg: #fffdef;
    --tip-bg: #f0fff4;
    --danger-bg: #ffeef0;
}

@media (prefers-color-scheme: dark) {
    :root {
        --bg-color: #0d1117;
        --text-color: #c9d1d9;
        --border-color: #30363d;
        --link-color: #58a6ff;
        --link-visited: #8e96f0;
        --link-hover: #79c0ff;
        --sidebar-bg: #161b22;
        --code-bg: #161b22;
        --table-border: #30363d;
        --table-header-bg: #161b22;
        --blockquote-border: #30363d;
        --muted-color: #8b949e;
        --accent-color: #58a6ff;

        /* GitHub Dark Additional Colors */
        --success-color: #238636;
        --warning-color: #9e6a03;
        --danger-color: #f85149;
        --info-color: #58a6ff;

        /* Dark Versions of Notes */
        --note-bg: #0c2d6b;
        --warning-bg: #5c4c0a;
        --tip-bg: #1a5321;
        --danger-bg: #78191e;
    }
}

/* ============ Reset & Base ============ */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
}

body {
    font-size: 17px;
    line-height: 1.8;
    color: var(--text-color);
    background-color: var(--bg-color);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    text-rendering: optimizeLegibility;
    max-width: 1200px;
    margin: 0 auto;
    min-height: 100vh;
    display: flex;
}

/* ============ Layout ============ */
.main-content {
    margin-left: 320px;
    min-height: 100vh;
    padding: var(--spacing-xl) var(--spacing-xl) var(--spacing-xl) 60px;
    max-width: 900px;
    margin-right: auto;
    flex: 1;
    display: flex;
    flex-direction: column;
}

/* ============ Typography - Optimized for Reading ============ */
h1, h2, h3, h4, h5, h6 {
    font-weight: 600;
    line-height: 1.3;
    margin: var(--spacing-xl) 0 var(--spacing-md);
    padding: 0;
    color: var(--text-color);
    letter-spacing: -0.01em;
}

h1 {
    font-size: 2.8em;
    border-bottom: 2px solid var(--border-color);
    padding-bottom: var(--spacing-sm);
    margin-top: 0;
    margin-bottom: var(--spacing-xl);
    font-weight: 700;
}

h2 {
    font-size: 2.2em;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: var(--spacing-xs);
    margin-top: var(--spacing-xl);
    font-weight: 600;
}

h3 {
    font-size: 1.8em;
    margin-top: var(--spacing-lg);
    font-weight: 600;
}

h4 {
    font-size: 1.5em;
    font-weight: 600;
    margin-top: var(--spacing-lg);
}

h5 {
    font-size: 1.3em;
    font-weight: 500;
    color: var(--muted-color);
}

h6 {
    font-size: 1.1em;
    font-weight: 500;
    color: var(--muted-color);
}

p {
    margin: var(--spacing-lg) 0;
    font-size: 1.125em;
    line-height: 1.8;
    text-align: justify;
    hyphens: auto;
}

/* ============ Links ============ */
a {
    color: var(--link-color);
    text-decoration: none;
    background: none;
    transition: color 0.2s ease;
    border-bottom: 1px solid transparent;
    padding-bottom: 1px;
}

a:visited {
    color: var(--link-visited);
}

a:hover {
    color: var(--link-hover);
    text-decoration: none;
    border-bottom-color: var(--link-hover);
}

a:active {
    color: #f9826c;
}

/* ============ Code Blocks & Inline Code ============ */
pre {
    background-color: var(--code-bg);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    padding: var(--spacing-lg);
    margin: var(--spacing-xl) 0;
    overflow-x: auto;
    font-family: 'SFMono-Regular', Consolas, 'Liberation Mono', Menlo, monospace;
    font-size: 0.95em;
    line-height: 1.6;
    box-shadow: inset 0 1px 3px rgba(0,0,0,0.05);
}

code {
    background-color: var(--code-bg);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius-sm);
    padding: 0.2em 0.4em;
    font-family: 'SFMono-Regular', Consolas, 'Liberation Mono', Menlo, monospace;
    font-size: 0.95em;
}

pre code {
    background: none;
    border: none;
    padding: 0;
    font-size: 0.95em;
}

/* ============ Tables - Clean Style ============ */
table {
    border-collapse: collapse;
    width: 100%;
    margin: var(--spacing-xl) 0;
    font-size: 0.95em;
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    overflow: hidden;
    box-shadow: var(--shadow);
}

th {
    background-color: var(--table-header-bg);
    font-weight: 600;
    text-align: left;
    padding: var(--spacing-md);
    border-bottom: 2px solid var(--border-color);
}

td {
    padding: var(--spacing-md);
    border-bottom: 1px solid var(--border-color);
    line-height: 1.6;
}

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

tr:hover {
    background-color: var(--sidebar-bg);
}

/* ============ Blockquotes - Clean Style ============ */
blockquote {
    border-left: 4px solid var(--blockquote-border);
    margin: var(--spacing-xl) 0;
    padding: var(--spacing-md) var(--spacing-lg);
    background-color: var(--sidebar-bg);
    border-radius: 0 var(--border-radius) var(--border-radius) 0;
    font-size: 1.1em;
    line-height: 1.7;
    font-style: italic;
}

blockquote p {
    margin: 0;
    font-style: italic;
}

/* ============ Images ============ */
img {
    max-width: 100%;
    height: auto;
    border-radius: var(--border-radius);
    border: 1px solid var(--border-color);
    margin: var(--spacing-lg) 0;
}

figure {
    margin: var(--spacing-xl) 0;
    text-align: center;
}

figcaption {
    margin-top: var(--spacing-sm);
    font-size: 0.9em;
    color: var(--muted-color);
    text-align: center;
    line-height: 1.5;
}

/* ============ Special Content Blocks - Clean Style ============ */
.note {
    background-color: var(--note-bg);
    border-left: 4px solid var(--info-color);
    padding: var(--spacing-lg);
    margin: var(--spacing-xl) 0;
    border-radius: 0 var(--border-radius) var(--border-radius) 0;
}

.note:before {
    content: "Note";
    display: block;
    font-weight: 600;
    color: var(--info-color);
    margin-bottom: var(--spacing-sm);
    font-size: 0.9em;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.warning {
    background-color: var(--warning-bg);
    border-left: 4px solid var(--warning-color);
    padding: var(--spacing-lg);
    margin: var(--spacing-xl) 0;
    border-radius: 0 var(--border-radius) var(--border-radius) 0;
}

.warning:before {
    content: "Warning";
    display: block;
    font-weight: 600;
    color: var(--warning-color);
    margin-bottom: var(--spacing-sm);
    font-size: 0.9em;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.tip {
    background-color: var(--tip-bg);
    border-left: 4px solid var(--success-color);
    padding: var(--spacing-lg);
    margin: var(--spacing-xl) 0;
    border-radius: 0 var(--border-radius) var(--border-radius) 0;
}

.tip:before {
    content: "Tip";
    display: block;
    font-weight: 600;
    color: var(--success-color);
    margin-bottom: var(--spacing-sm);
    font-size: 0.9em;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.danger {
    background-color: var(--danger-bg);
    border-left: 4px solid var(--danger-color);
    padding: var(--spacing-lg);
    margin: var(--spacing-xl) 0;
    border-radius: 0 var(--border-radius) var(--border-radius) 0;
}

.danger:before {
    content: "Important";
    display: block;
    font-weight: 600;
    color: var(--danger-color);
    margin-bottom: var(--spacing-sm);
    font-size: 0.9em;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

/* ============ Article Structure ============ */
.article-header {
    margin-bottom: var(--spacing-xl);
    padding-bottom: var(--spacing-lg);
    border-bottom: 1px solid var(--border-color);
}

.article-title {
    margin-bottom: var(--spacing-md);
}

.article-meta {
    display: flex;
    gap: var(--spacing-lg);
    color: var(--muted-color);
    font-size: 0.9em;
    margin-top: var(--spacing-md);
}

.article-meta span {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
}

.article-content {
    font-size: 1.125em;
    line-height: 1.8;
}

/* ============ Keyboard Shortcuts ============ */
kbd {
    background-color: var(--code-bg);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius-sm);
    box-shadow: 0 1px 0 var(--border-color);
    color: var(--text-color);
    display: inline-block;
    font-family: 'SFMono-Regular', Consolas, 'Liberation Mono', Menlo, monospace;
    font-size: 0.85em;
    line-height: 1;
    padding: 0.3em 0.5em;
    margin: 0 0.2em;
    vertical-align: middle;
}

/* ============ Home Page Specific ============ */
.hero-section {
    padding: var(--spacing-xl) 0;
    border-bottom: 1px solid var(--border-color);
    margin-bottom: var(--spacing-xl);
}

.hero-title {
    font-size: 3em;
    font-weight: 700;
    color: var(--text-color);
    margin: 0 0 var(--spacing-md);
    border: none;
    letter-spacing: -0.02em;
}

.hero-subtitle {
    font-size: 1.4em;
    color: var(--muted-color);
    max-width: 900px;
    margin: 0 0 var(--spacing-xl);
    line-height: 1.7;
    font-weight: 400;
}

.stats-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
    gap: var(--spacing-lg);
    margin: var(--spacing-xl) 0;
}

.stat-item {
    text-align: center;
    padding: var(--spacing-lg);
    background-color: var(--sidebar-bg);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    transition: all 0.3s ease;
}

.stat-item:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-hover);
    border-color: var(--accent-color);
}

.stat-number {
    font-size: 2.5em;
    font-weight: 700;
    color: var(--accent-color);
    margin-bottom: var(--spacing-xs);
    font-feature-settings: "tnum";
}

.stat-label {
    font-size: 0.95em;
    color: var(--muted-color);
    text-transform: uppercase;
    letter-spacing: 0.5px;
    font-weight: 500;
}

.project-info {
    margin: var(--spacing-xl) 0;
    padding: var(--spacing-xl);
    background-color: var(--sidebar-bg);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
}

.project-title {
    font-size: 2em;
    font-weight: 600;
    margin: 0 0 var(--spacing-lg);
    border: none;
}

.project-description {
    font-size: 1.125em;
    line-height: 1.8;
}

.highlight {
    background-color: var(--sidebar-bg);
    padding: var(--spacing-xl);
    border-left: 4px solid var(--accent-color);
    margin: var(--spacing-xl) 0;
    border-radius: 0 var(--border-radius) var(--border-radius) 0;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-lg);
    margin: var(--spacing-xl) 0;
}

.feature-card {
    padding: var(--spacing-xl);
    background-color: var(--bg-color);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    transition: all 0.3s ease;
    height: 100%;
}

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

.feature-icon {
    font-size: 2em;
    color: var(--accent-color);
    margin-bottom: var(--spacing-md);
}

.feature-title {
    font-weight: 600;
    margin: 0 0 var(--spacing-md);
    font-size: 1.3em;
    color: var(--text-color);
}

.feature-text {
    font-size: 1.05em;
    color: var(--muted-color);
    line-height: 1.7;
}

.content-preview {
    margin: var(--spacing-xl) 0;
}

.section-title {
    font-size: 1.8em;
    font-weight: 600;
    margin: 0 0 var(--spacing-lg);
    border: none;
}

/* ============ Reading Experience Improvements ============ */
.reading-section {
    margin: var(--spacing-xl) 0;
    padding: var(--spacing-lg) 0;
    border-top: 1px solid var(--border-color);
}

.reading-section:first-of-type {
    border-top: none;
    padding-top: 0;
}

.paragraph-group {
    margin: var(--spacing-xl) 0;
}

.paragraph-group p {
    margin: var(--spacing-md) 0;
}

/* ============ Math Formulas ============ */
.math-formula {
    font-family: "Times New Roman", serif;
    font-style: italic;
    background-color: var(--sidebar-bg);
    padding: var(--spacing-md);
    border-radius: var(--border-radius);
    margin: var(--spacing-lg) 0;
    text-align: center;
    border: 1px solid var(--border-color);
}

/* ============ Footnotes ============ */
.footnotes {
    margin-top: var(--spacing-xl);
    padding-top: var(--spacing-lg);
    border-top: 2px solid var(--border-color);
    font-size: 0.9em;
    color: var(--muted-color);
}

/* ============ Article Navigation ============ */
.article-navigation {
    display: flex;
    justify-content: space-between;
    margin: var(--spacing-xl) 0;
    padding: var(--spacing-lg) 0;
    border-top: 1px solid var(--border-color);
    border-bottom: 1px solid var(--border-color);
}

.nav-link {
    padding: var(--spacing-md);
    color: var(--text-color);
    text-decoration: none;
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    transition: all 0.2s ease;
    min-width: 200px;
    text-align: center;
}

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

/* ============ Tags for Articles ============ */
.article-tags {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-sm);
    margin: var(--spacing-lg) 0;
}

.tag {
    background-color: var(--sidebar-bg);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius-sm);
    padding: var(--spacing-xs) var(--spacing-sm);
    font-size: 0.85em;
    color: var(--muted-color);
    text-decoration: none;
    transition: all 0.2s ease;
}

.tag:hover {
    background-color: var(--accent-color);
    color: white;
    border-color: var(--accent-color);
}

/* ============ Mobile Menu Toggle ============ */
.mobile-menu-toggle {
    display: none;
    position: fixed;
    top: 16px;
    left: 16px;
    z-index: 1002;
    background: var(--bg-color);
    border: 1px solid var(--border-color);
    border-radius: 4px;
    width: 40px;
    height: 40px;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    box-shadow: 0 1px 3px rgba(0,0,0,0.1);
}

.mobile-menu-toggle i {
    font-size: 20px;
    color: var(--text-color);
}

/* ============ Sidebar Navigation ============ */
.sidebar {
    width: 320px;
    background: var(--bg-color);
    border-right: 1px solid var(--border-color);
    position: fixed;
    top: 0;
    left: 0;
    bottom: 0;
    overflow-y: auto;
    z-index: 1000;
    transition: transform 0.3s ease;
}

.sidebar-header {
    padding: 20px;
    border-bottom: 1px solid var(--border-color);
    background: var(--bg-color);
    position: sticky;
    top: 0;
    z-index: 10;
}

.logo-section {
    display: flex;
    align-items: center;
    gap: 12px;
}

.logo-icon {
    color: var(--text-color);
    font-size: 22px;
}

.site-title {
    font-size: 18px;
    font-weight: 600;
    color: var(--text-color);
}

.site-subtitle {
    font-size: 12px;
    color: var(--muted-color);
    margin-top: 4px;
}

/* Support Button */
.support-btn {
    display: block;
    padding: 12px 20px;
    margin: 20px;
    background: var(--sidebar-bg);
    color: var(--text-color);
    text-decoration: none;
    border-radius: 4px;
    font-weight: 500;
    font-size: 14px;
    border: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    transition: all 0.2s;
    text-align: center;
}

.support-btn:hover {
    background: var(--code-bg);
    border-color: var(--accent-color);
}

.support-icon {
    color: #e25555;
}

/* Topics Navigation */
.topics-nav {
    padding: 0 0 20px 0;
}

.topic-category {
    margin-bottom: 24px;
}

.category-title {
    padding: 8px 20px;
    font-size: 11px;
    font-weight: 600;
    color: var(--muted-color);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.topic-section {
    margin-bottom: 4px;
}

.nav-section-title {
    padding: 12px 20px;
    font-size: 14px;
    font-weight: 600;
    color: var(--text-color);
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    user-select: none;
    transition: background 0.2s;
    background: var(--sidebar-bg);
    border-left: 4px solid var(--accent-color);
    margin: 8px 0;
}

.nav-section-title:hover {
    background: var(--code-bg);
}

.toggle-icon {
    font-size: 12px;
    color: var(--muted-color);
    transition: transform 0.2s;
}

.nav-section-title.active .toggle-icon {
    transform: rotate(90deg);
}

.topic-list {
    display: none;
}

.nav-section-title.active + .topic-list {
    display: block;
}

.topic-item {
    list-style: none;
}

.topic-link {
    display: flex;
    align-items: flex-start;
    padding: 8px 20px 8px 28px;
    color: var(--muted-color);
    text-decoration: none;
    font-size: 13px;
    line-height: 1.4;
    transition: background 0.2s;
    border-left: 1px solid transparent;
}

.topic-link:hover {
    background: var(--sidebar-bg);
    border-left-color: var(--border-color);
}

.topic-link.active {
    background: var(--code-bg);
    color: var(--text-color);
    border-left-color: var(--muted-color);
    font-weight: 500;
}

.topic-number {
    color: var(--muted-color);
    font-size: 11px;
    min-width: 24px;
    margin-right: 8px;
    font-variant-numeric: tabular-nums;
    margin-top: 1px;
}

.intro-link {
    color: var(--accent-color);
    font-weight: 500;
}

.intro-link .topic-number {
    color: var(--accent-color);
    font-weight: 600;
}

/* Welcome Page */
.welcome-container {
    flex: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 40px;
    text-align: center;
    background: var(--sidebar-bg);
}

.welcome-title {
    font-size: 32px;
    font-weight: 700;
    color: var(--text-color);
    margin-bottom: 16px;
    background: linear-gradient(135deg, #4285f4 0%, #34a853 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.welcome-subtitle {
    font-size: 18px;
    color: var(--muted-color);
    margin-bottom: 24px;
    max-width: 600px;
    line-height: 1.6;
}

.welcome-features {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 20px;
    max-width: 900px;
    margin-top: 40px;
}

.welcome-feature-card {
    background: var(--bg-color);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 24px;
    text-align: left;
    transition: transform 0.2s, box-shadow 0.2s;
}

.welcome-feature-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-hover);
}

.welcome-feature-icon {
    font-size: 24px;
    color: var(--accent-color);
    margin-bottom: 16px;
}

.welcome-feature-title {
    font-size: 16px;
    font-weight: 600;
    color: var(--text-color);
    margin-bottom: 8px;
}

.welcome-feature-description {
    font-size: 14px;
    color: var(--muted-color);
    line-height: 1.5;
}

/* Overlay for mobile */
.overlay {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0,0,0,0.7);
    z-index: 999;
}

.overlay.active {
    display: block;
}

/* ============ Print Styles ============ */
@media print {
    .main-content {
        margin-left: 0;
        max-width: 100%;
        padding: 0;
    }

    body {
        font-size: 12pt;
        line-height: 1.5;
    }

    h1 { font-size: 24pt; }
    h2 { font-size: 18pt; }
    h3 { font-size: 14pt; }

    .article-navigation,
    .mobile-menu-toggle,
    .feature-icon,
    .stats-container,
    .sidebar {
        display: none;
    }

    a {
        color: #000;
        text-decoration: underline;
    }

    pre, code {
        background-color: #f5f5f5;
        border: 1px solid #ddd;
        font-size: 10pt;
    }

    .note,
    .warning,
    .tip,
    .danger {
        break-inside: avoid;
    }
}

/* ============ MOBILE VERSION - ОПТИМИЗИРОВАННАЯ ============ */
@media (max-width: 768px) {
    body {
        font-size: 16px;
        line-height: 1.7;
        display: block;
        max-width: 100%;
    }

    .main-content {
        margin-left: 0;
        padding: var(--spacing-md);
        width: 100%;
        max-width: 100%;
        padding-top: 70px;
        min-height: auto;
    }

    h1 {
        font-size: 1.8em;
        margin-bottom: var(--spacing-lg);
        padding-bottom: var(--spacing-sm);
        border-bottom-width: 2px;
        line-height: 1.2;
        margin-top: var(--spacing-lg);
    }

    h2 {
        font-size: 1.5em;
        margin-top: var(--spacing-lg);
        padding-bottom: var(--spacing-xs);
    }

    h3 {
        font-size: 1.3em;
        margin-top: var(--spacing-md);
    }

    h4 {
        font-size: 1.1em;
        margin-top: var(--spacing-md);
    }

    h5, h6 {
        font-size: 1em;
    }

    p {
        font-size: 1.05em;
        line-height: 1.7;
        text-align: left;
        hyphens: auto;
        margin: var(--spacing-md) 0;
        word-wrap: break-word;
        overflow-wrap: break-word;
    }

    /* Mobile Menu - улучшенная доступность */
    .mobile-menu-toggle {
        display: flex;
        top: 12px;
        left: 12px;
        width: 44px;
        height: 44px;
        border-radius: 8px;
        z-index: 1003;
    }

    .sidebar {
        transform: translateX(-100%);
        width: 85%;
        max-width: 320px;
        box-shadow: 4px 0 20px rgba(0,0,0,0.2);
        -webkit-overflow-scrolling: touch;
        overscroll-behavior: contain;
    }

    .sidebar.active {
        transform: translateX(0);
    }

    .sidebar-header {
        padding: 16px;
        padding-top: 70px;
        min-height: auto;
    }

    /* Улучшенная навигация на мобильных */
    .topic-link {
        padding: 10px 16px 10px 24px;
        font-size: 14px;
        line-height: 1.4;
        min-height: 44px;
        align-items: center;
    }

    .topic-number {
        min-width: 22px;
        margin-right: 8px;
        font-size: 12px;
    }

    .nav-section-title {
        padding: 14px 16px;
        font-size: 15px;
        min-height: 48px;
        align-items: center;
    }

    .category-title {
        padding: 10px 16px;
        font-size: 12px;
    }

    .support-btn {
        margin: 16px;
        padding: 14px 16px;
        font-size: 15px;
        min-height: 48px;
    }

    /* Hero section - улучшенная для мобильных */
    .hero-section {
        padding: var(--spacing-md) 0;
        margin-bottom: var(--spacing-lg);
    }

    .hero-title {
        font-size: 1.8em;
        text-align: left;
        line-height: 1.2;
        margin-bottom: var(--spacing-md);
    }

    .hero-subtitle {
        font-size: 1.1em;
        text-align: left;
        margin: 0 0 var(--spacing-md);
        line-height: 1.6;
    }

    /* Stats - адаптивная сетка */
    .stats-container {
        grid-template-columns: repeat(2, 1fr);
        gap: var(--spacing-sm);
        margin: var(--spacing-md) 0;
    }

    .stat-item {
        padding: var(--spacing-md);
        min-height: 100px;
        display: flex;
        flex-direction: column;
        justify-content: center;
    }

    .stat-number {
        font-size: 1.6em;
        margin-bottom: var(--spacing-xs);
    }

    .stat-label {
        font-size: 0.85em;
    }

    /* Project info - лучшая читаемость */
    .project-info {
        padding: var(--spacing-md);
        margin: var(--spacing-md) 0;
    }

    .project-title {
        font-size: 1.4em;
        text-align: left;
        margin-bottom: var(--spacing-md);
    }

    .project-description {
        font-size: 1.05em;
        line-height: 1.6;
    }

    /* Features grid - одна колонка */
    .features-grid {
        grid-template-columns: 1fr;
        gap: var(--spacing-md);
        margin: var(--spacing-md) 0;
    }

    .feature-card {
        padding: var(--spacing-md);
        min-height: auto;
    }

    .feature-icon {
        font-size: 1.6em;
        margin-bottom: var(--spacing-sm);
    }

    .feature-title {
        font-size: 1.1em;
        margin-bottom: var(--spacing-sm);
    }

    .feature-text {
        font-size: 0.95em;
        line-height: 1.6;
    }

    /* Special blocks - лучшее отображение */
    .note,
    .warning,
    .tip,
    .danger {
        padding: var(--spacing-md);
        margin: var(--spacing-md) 0;
        font-size: 0.95em;
        line-height: 1.6;
    }

    /* Tables - горизонтальная прокрутка */
    table {
        display: block;
        overflow-x: auto;
        -webkit-overflow-scrolling: touch;
        font-size: 0.9em;
    }

    th, td {
        padding: var(--spacing-sm);
        min-width: 80px;
    }

    /* Code blocks - лучшая читаемость */
    pre {
        padding: var(--spacing-md);
        margin: var(--spacing-md) 0;
        font-size: 0.9em;
    }

    code {
        font-size: 0.9em;
        word-break: break-word;
    }

    /* Navigation links - удобные кнопки */
    .article-navigation {
        flex-direction: column;
        gap: var(--spacing-sm);
        margin: var(--spacing-md) 0;
        padding: var(--spacing-md) 0;
    }

    .nav-link {
        min-width: 100%;
        padding: var(--spacing-md);
        font-size: 1em;
        text-align: center;
    }

    /* Images - оптимальное отображение */
    img {
        margin: var(--spacing-md) 0;
        border-radius: var(--border-radius-sm);
    }

    figure {
        margin: var(--spacing-md) 0;
    }

    figcaption {
        font-size: 0.85em;
        padding: 0 var(--spacing-sm);
    }

    /* Blockquotes - компактнее */
    blockquote {
        margin: var(--spacing-md) 0;
        padding: var(--spacing-md);
        font-size: 1em;
    }

    /* Welcome page - адаптивная */
    .welcome-container {
        padding: 20px;
        padding-top: 80px;
        min-height: calc(100vh - 80px);
    }

    .welcome-title {
        font-size: 1.8em;
        margin-top: 0;
        margin-bottom: var(--spacing-md);
    }

    .welcome-subtitle {
        font-size: 1.1em;
        line-height: 1.6;
        margin-bottom: var(--spacing-lg);
    }

    .welcome-features {
        grid-template-columns: 1fr;
        gap: var(--spacing-md);
        margin-top: var(--spacing-lg);
    }

    .welcome-feature-card {
        padding: var(--spacing-md);
    }

    .welcome-feature-icon {
        font-size: 1.8em;
        margin-bottom: var(--spacing-sm);
    }

    .welcome-feature-title {
        font-size: 1.1em;
        margin-bottom: var(--spacing-xs);
    }

    .welcome-feature-description {
        font-size: 0.95em;
        line-height: 1.5;
    }

    /* Reading sections - лучшее разделение */
    .reading-section {
        margin: var(--spacing-md) 0;
        padding: var(--spacing-md) 0;
    }

    .paragraph-group {
        margin: var(--spacing-md) 0;
    }

    .paragraph-group p {
        margin: var(--spacing-sm) 0;
    }

    /* Tags - компактнее */
    .article-tags {
        gap: var(--spacing-xs);
        margin: var(--spacing-md) 0;
    }

    .tag {
        padding: 4px 8px;
        font-size: 0.8em;
    }

    /* Article meta - адаптивная */
    .article-meta {
        flex-wrap: wrap;
        gap: var(--spacing-sm);
        font-size: 0.85em;
    }

    /* Highlight blocks */
    .highlight {
        padding: var(--spacing-md);
        margin: var(--spacing-md) 0;
    }

    /* Math formulas */
    .math-formula {
        padding: var(--spacing-sm);
        margin: var(--spacing-md) 0;
        font-size: 0.9em;
        overflow-x: auto;
    }

    /* Footnotes */
    .footnotes {
        margin-top: var(--spacing-md);
        padding-top: var(--spacing-md);
        font-size: 0.85em;
    }

    /* Overlay для мобильного меню */
    .overlay.active {
        display: block;
        backdrop-filter: blur(2px);
        -webkit-backdrop-filter: blur(2px);
    }
}

@media (max-width: 480px) {
    body {
        font-size: 15px;
        line-height: 1.6;
    }

    .main-content {
        padding: 14px;
        padding-top: 70px;
    }

    h1 {
        font-size: 1.6em;
        margin-top: var(--spacing-md);
        margin-bottom: var(--spacing-md);
    }

    h2 {
        font-size: 1.3em;
        margin-top: var(--spacing-md);
    }

    h3 {
        font-size: 1.2em;
    }

    p {
        font-size: 1em;
        line-height: 1.6;
    }

    /* Еще более компактные stats */
    .stats-container {
        grid-template-columns: 1fr;
        gap: 10px;
    }

    .stat-item {
        padding: 12px;
        min-height: 80px;
    }

    .stat-number {
        font-size: 1.4em;
    }

    .hero-title {
        font-size: 1.5em;
    }

    .hero-subtitle {
        font-size: 1em;
    }

    /* Кнопка меню - больше для удобства тапа */
    .mobile-menu-toggle {
        width: 46px;
        height: 46px;
        top: 10px;
        left: 10px;
    }

    .sidebar {
        width: 90%;
    }

    /* Улучшенные отступы для навигации */
    .topic-link {
        padding: 12px 16px 12px 24px;
        font-size: 13px;
    }

    .nav-section-title {
        padding: 16px;
        font-size: 14px;
    }

    /* Более компактные карточки */
    .feature-card,
    .welcome-feature-card {
        padding: 16px;
    }

    /* Таблицы - еще компактнее */
    th, td {
        padding: 8px 10px;
        font-size: 0.85em;
    }

    /* Code blocks */
    pre {
        padding: 12px;
        font-size: 0.85em;
    }

    /* Welcome page - оптимизация */
    .welcome-title {
        font-size: 1.6em;
    }

    .welcome-subtitle {
        font-size: 1em;
    }
}

@media (max-width: 360px) {
    .main-content {
        padding: 12px;
        padding-top: 65px;
    }

    .mobile-menu-toggle {
        width: 42px;
        height: 42px;
        top: 8px;
        left: 8px;
    }

    .sidebar {
        width: 95%;
    }

    .stats-container {
        gap: 8px;
    }

    .stat-item {
        padding: 10px;
    }

    h1 {
        font-size: 1.4em;
    }

    h2 {
        font-size: 1.2em;
    }

    .hero-title {
        font-size: 1.4em;
    }
}

/* ============ Large Desktop Screens ============ */
@media (min-width: 1400px) {
    body {
        max-width: 1400px;
    }

    .main-content {
        max-width: 1000px;
        padding: var(--spacing-xl) 60px;
    }

    .hero-subtitle {
        max-width: 1000px;
    }
}

/* ============ Accessibility Improvements ============ */
@media (prefers-reduced-motion: reduce) {
    * {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

:focus {
    outline: 2px solid var(--accent-color);
    outline-offset: 2px;
}

/* Улучшение доступности для мобильных */
@media (max-width: 768px) {
    :focus {
        outline-offset: 1px;
    }

    a, button, .topic-link, .nav-section-title {
        min-height: 44px;
        display: flex;
        align-items: center;
    }
}

/* ============ Selection Color ============ */
::selection {
    background-color: rgba(3, 102, 214, 0.2);
    color: var(--text-color);
}

::-moz-selection {
    background-color: rgba(3, 102, 214, 0.2);
    color: var(--text-color);
}

/* ============ Utility Classes ============ */
.text-center { text-align: center; }
.text-right { text-align: right; }
.text-justify { text-align: justify; }
.text-muted { color: var(--muted-color); }
.mt-1 { margin-top: var(--spacing-xs); }
.mt-2 { margin-top: var(--spacing-sm); }
.mt-3 { margin-top: var(--spacing-md); }
.mt-4 { margin-top: var(--spacing-lg); }
.mt-5 { margin-top: var(--spacing-xl); }
.mb-1 { margin-bottom: var(--spacing-xs); }
.mb-2 { margin-bottom: var(--spacing-sm); }
.mb-3 { margin-bottom: var(--spacing-md); }
.mb-4 { margin-bottom: var(--spacing-lg); }
.mb-5 { margin-bottom: var(--spacing-xl); }
.p-1 { padding: var(--spacing-xs); }
.p-2 { padding: var(--spacing-sm); }
.p-3 { padding: var(--spacing-md); }
.p-4 { padding: var(--spacing-lg); }
.p-5 { padding: var(--spacing-xl); }

/* ============ Reading Line Height ============ */
.reading-line {
    position: relative;
}

.reading-line:after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(transparent 1.7em, rgba(0,0,0,0.03) 1.7em);
    background-size: 100% 1.8em;
    pointer-events: none;
    z-index: -1;
}

/* ============ Comfortable Paragraph Spacing ============ */
.comfortable-reading p {
    margin: 1.8em 0;
    text-indent: 1.5em;
}

.comfortable-reading p:first-of-type {
    text-indent: 0;
}

.comfortable-reading h1,
.comfortable-reading h2,
.comfortable-reading h3,
.comfortable-reading h4 {
    margin-top: 2.5em;
    margin-bottom: 1em;
}

/* ============ Clean Blockquote Style ============ */
.clean-quote {
    border-left: none;
    background: none;
    font-style: normal;
    padding: 0;
    margin: 2em 2em;
    text-align: center;
    color: var(--muted-color);
}

.clean-quote:before {
    content: "“";
    font-size: 3em;
    color: var(--border-color);
    line-height: 0;
    margin-right: 0.1em;
    vertical-align: -0.4em;
}

.clean-quote:after {
    content: "”";
    font-size: 3em;
    color: var(--border-color);
    line-height: 0;
    margin-left: 0.1em;
    vertical-align: -0.4em;
}