:root {
    --bg-primary: #0f172a;
    --bg-secondary: #1e293b;
    --bg-tertiary: #334155;
    --text-primary: #f1f5f9;
    --text-secondary: #94a3b8;
    --text-muted: #64748b;
    --accent-primary: #818cf8;
    --accent-secondary: #c084fc;
    --accent-gradient: linear-gradient(135deg, #818cf8 0%, #c084fc 100%);
    --border-color: #334155;
    --code-bg: #1e1e1e;
    --success: #4ade80;
    --warning: #fbbf24;
    --danger: #f87171;
    --font-sans: 'Inter', system-ui, -apple-system, sans-serif;
    --font-mono: 'JetBrains Mono', 'Fira Code', monospace;

    /* New visual enhancement variables */
    --glow-primary: 0 0 40px rgba(129, 140, 248, 0.3);
    --glow-secondary: 0 0 30px rgba(192, 132, 252, 0.2);
    --transition-smooth: cubic-bezier(0.4, 0, 0.2, 1);
    --glass-bg: rgba(30, 41, 59, 0.8);
    --glass-border: rgba(255, 255, 255, 0.1);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-sans);
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    overflow-x: hidden;
}

a {
    color: var(--accent-primary);
    text-decoration: none;
    transition: color 0.2s var(--transition-smooth);
}

a:hover {
    color: var(--accent-secondary);
}

/* Skip to content link for accessibility */
.skip-link {
    position: absolute;
    top: -100%;
    left: 50%;
    transform: translateX(-50%);
    padding: 1rem 2rem;
    background: var(--accent-gradient);
    color: white;
    border-radius: 0 0 0.5rem 0.5rem;
    z-index: 1000;
    transition: top 0.3s;
}

.skip-link:focus {
    top: 0;
}

/* Layout */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
}

/* ========================================
   HEADER & NAVIGATION
   ======================================== */

header {
    background-color: var(--glass-bg);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--glass-border);
    position: sticky;
    top: 0;
    z-index: 100;
    padding: 1rem 0;
}

nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    transition: opacity 0.2s;
}

.logo:hover {
    opacity: 0.8;
}

.nav-links {
    display: flex;
    gap: 2rem;
}

.nav-links a {
    color: var(--text-secondary);
    font-weight: 500;
    position: relative;
    padding: 0.25rem 0;
    transition: color 0.2s;
}

.nav-links a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--accent-gradient);
    transition: width 0.3s var(--transition-smooth);
}

.nav-links a:hover::after,
.nav-links a.active::after {
    width: 100%;
}

.nav-links a:hover,
.nav-links a.active {
    color: var(--text-primary);
}

/* Mobile Menu Button */
.mobile-menu-btn {
    display: none;
    background: none;
    border: none;
    cursor: pointer;
    padding: 0.5rem;
    z-index: 200;
}

.mobile-menu-btn span {
    display: block;
    width: 24px;
    height: 2px;
    background-color: var(--text-primary);
    margin: 6px 0;
    transition: all 0.3s var(--transition-smooth);
    border-radius: 2px;
}

.mobile-menu-btn.active span:nth-child(1) {
    transform: rotate(45deg) translate(6px, 6px);
}

.mobile-menu-btn.active span:nth-child(2) {
    opacity: 0;
}

.mobile-menu-btn.active span:nth-child(3) {
    transform: rotate(-45deg) translate(6px, -6px);
}

/* Mobile Navigation Drawer */
.mobile-nav {
    display: none;
    position: fixed;
    top: 0;
    right: -100%;
    width: 280px;
    height: 100vh;
    background: var(--bg-secondary);
    border-left: 1px solid var(--border-color);
    padding: 5rem 2rem 2rem;
    transition: right 0.3s var(--transition-smooth);
    z-index: 150;
    overflow-y: auto;
}

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

.mobile-nav a {
    display: block;
    padding: 1rem 0;
    color: var(--text-secondary);
    font-size: 1.1rem;
    border-bottom: 1px solid var(--border-color);
    transition: all 0.2s;
}

.mobile-nav a:hover,
.mobile-nav a.active {
    color: var(--accent-primary);
    padding-left: 0.5rem;
}

.nav-overlay {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(4px);
    z-index: 140;
    opacity: 0;
    transition: opacity 0.3s;
}

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

/* ========================================
   SCROLL PROGRESS INDICATOR
   ======================================== */

.scroll-progress {
    position: fixed;
    top: 0;
    left: 0;
    height: 3px;
    background: var(--accent-gradient);
    z-index: 1000;
    transition: width 0.1s;
    box-shadow: var(--glow-primary);
}

/* ========================================
   SCROLL TO TOP BUTTON
   ======================================== */

.scroll-top-btn {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    width: 48px;
    height: 48px;
    background: var(--accent-gradient);
    border: none;
    border-radius: 50%;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    visibility: hidden;
    transform: translateY(20px);
    transition: all 0.3s var(--transition-smooth);
    z-index: 90;
    box-shadow: var(--glow-primary);
}

.scroll-top-btn.visible {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.scroll-top-btn:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 30px rgba(129, 140, 248, 0.4);
}

.scroll-top-btn svg {
    width: 24px;
    height: 24px;
    fill: white;
}

/* ========================================
   HERO SECTION
   ======================================== */

.hero {
    padding: 8rem 0 6rem;
    text-align: center;
    background:
        radial-gradient(circle at 20% 50%, rgba(129, 140, 248, 0.1) 0%, transparent 50%),
        radial-gradient(circle at 80% 50%, rgba(192, 132, 252, 0.1) 0%, transparent 50%),
        radial-gradient(circle at top center, rgba(129, 140, 248, 0.15), transparent 40%);
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23818cf8' fill-opacity='0.03'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
    opacity: 0.5;
}

.hero h1 {
    font-size: 4rem;
    font-weight: 800;
    margin-bottom: 1.5rem;
    line-height: 1.1;
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    animation: fadeInUp 0.8s var(--transition-smooth);
    position: relative;
}

.hero p {
    font-size: 1.25rem;
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto 3rem;
    animation: fadeInUp 0.8s 0.1s var(--transition-smooth) backwards;
    position: relative;
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}



.cta-buttons {
    display: flex;
    gap: 1rem;
    justify-content: center;
    animation: fadeInUp 0.8s 0.2s var(--transition-smooth) backwards;
    position: relative;
}

/* Page navigation buttons (at bottom of content pages) */
.page-nav {
    display: flex;
    gap: 1rem;
    justify-content: center;
    margin-top: 3rem;
    text-align: center;
    flex-wrap: wrap;
}

/* Section title centered */
.section-title-centered {
    text-align: center;
    margin-bottom: 2rem;
}

/* ========================================
   BUTTONS
   ======================================== */

.btn {
    display: inline-block;
    padding: 0.75rem 1.5rem;
    border-radius: 0.5rem;
    font-weight: 600;
    transition: all 0.2s var(--transition-smooth);
    position: relative;
    overflow: hidden;
}

.btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.1), transparent);
    transition: left 0.5s;
}

.btn:hover::before {
    left: 100%;
}

.btn-primary {
    background: var(--accent-gradient);
    color: white;
    box-shadow: 0 4px 14px 0 rgba(129, 140, 248, 0.39);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(129, 140, 248, 0.4);
    color: white;
}

.btn-primary:active {
    transform: translateY(0);
}

.btn-secondary {
    background-color: var(--bg-secondary);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
}

.btn-secondary:hover {
    background-color: var(--bg-tertiary);
    border-color: var(--accent-primary);
    color: white;
}

/* ========================================
   CARDS GRID
   ======================================== */

.grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin: 4rem 0;
}

.card {
    background: var(--glass-bg);
    backdrop-filter: blur(10px);
    border: 1px solid var(--border-color);
    border-radius: 1rem;
    padding: 2rem;
    transition: all 0.3s var(--transition-smooth);
    position: relative;
    overflow: hidden;
}

.card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 2px;
    background: var(--accent-gradient);
    transform: scaleX(0);
    transition: transform 0.3s var(--transition-smooth);
}

.card:hover {
    transform: translateY(-8px);
    border-color: var(--accent-primary);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.3), var(--glow-secondary);
}

.card:hover::before {
    transform: scaleX(1);
}

.card h3 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.card p {
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
}

/* Numbered cards for learning path */
.card[data-step] {
    counter-increment: card-step;
}

.card[data-step]::after {
    content: attr(data-step);
    position: absolute;
    top: 1rem;
    right: 1rem;
    width: 32px;
    height: 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--accent-gradient);
    border-radius: 50%;
    font-weight: 700;
    font-size: 0.9rem;
    color: white;
    opacity: 0.9;
}

/* Card icon styling */
.card-icon {
    font-size: 2.5rem;
    margin-bottom: 1rem;
    display: block;
}

/* Feature badges on cards */
.card-badge {
    display: inline-block;
    padding: 0.25rem 0.75rem;
    background: rgba(129, 140, 248, 0.2);
    border: 1px solid var(--accent-primary);
    border-radius: 2rem;
    font-size: 0.75rem;
    font-weight: 600;
    color: var(--accent-primary);
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin-bottom: 1rem;
}

/* Grid with learning path style */
.learning-path .grid {
    counter-reset: card-step;
}

/* ========================================
   CONTENT PAGES
   ======================================== */

.content-wrapper {
    padding: 4rem 0;
    max-width: 900px;
    margin: 0 auto;
}

.section-title {
    font-size: 2.5rem;
    margin-bottom: 2rem;
    color: var(--text-primary);
    position: relative;
    display: inline-block;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: -0.5rem;
    left: 0;
    width: 60px;
    height: 4px;
    background: var(--accent-gradient);
    border-radius: 2px;
}

.content-block {
    margin-bottom: 4rem;
    animation: fadeInUp 0.6s var(--transition-smooth);
}

.content-block h2 {
    font-size: 2.25rem;
    margin-bottom: 1.75rem;
    margin-top: 0;
    color: var(--accent-primary);
    border-bottom: 2px solid var(--accent-primary);
    padding-bottom: 0.75rem;
    font-weight: 700;
    letter-spacing: -0.02em;
    line-height: 1.2;
}

.content-block h3 {
    font-size: 1.65rem;
    margin: 2.5rem 0 1.25rem;
    color: var(--text-primary);
    font-weight: 600;
    letter-spacing: -0.01em;
    line-height: 1.3;
}

.content-block h4 {
    font-size: 1.35rem;
    margin: 2rem 0 1rem;
    color: var(--text-secondary);
    font-weight: 600;
}

.content-block p {
    margin-bottom: 1.5rem;
    color: var(--text-primary);
    line-height: 1.8;
    font-size: 1.05rem;
}

.content-block ul,
.content-block ol {
    margin-bottom: 1.75rem;
    margin-top: 1rem;
    padding-left: 2.5rem;
    color: var(--text-primary);
}

.content-block ul {
    list-style: none;
}

.content-block ul>li {
    position: relative;
}

.content-block ul>li::before {
    content: '▸';
    position: absolute;
    left: -1.5rem;
    color: var(--accent-primary);
    font-weight: bold;
}

.content-block ol {
    list-style: none;
    counter-reset: ol-counter;
}

.content-block ol>li {
    position: relative;
    counter-increment: ol-counter;
}

.content-block ol>li::before {
    content: counter(ol-counter);
    position: absolute;
    left: -2rem;
    width: 1.5rem;
    height: 1.5rem;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--accent-gradient);
    border-radius: 50%;
    font-size: 0.8rem;
    font-weight: 600;
    color: white;
}

.content-block li {
    margin-bottom: 0.75rem;
    line-height: 1.7;
}

.content-block li:last-child {
    margin-bottom: 0;
}

.content-block strong {
    color: var(--accent-primary);
    font-weight: 600;
}

.content-block em {
    color: var(--text-secondary);
    font-style: italic;
}

/* ========================================
   CODE BLOCKS
   ======================================== */

pre {
    background: #1e1e1e;
    padding: 1.75rem;
    border-radius: 0.75rem;
    overflow-x: auto;
    margin-bottom: 2rem;
    margin-top: 1rem;
    border: 2px solid #333;
    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.5);
    position: relative;
    transition: all 0.3s var(--transition-smooth);
}

pre:hover {
    border-color: rgba(129, 140, 248, 0.4);
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.4), var(--glow-secondary);
}

/* Code block language label */
pre[data-language]::before {
    content: attr(data-language);
    position: absolute;
    top: 0;
    right: 0;
    padding: 0.25rem 0.75rem;
    background: var(--accent-gradient);
    color: white;
    font-size: 0.75rem;
    font-weight: 600;
    border-radius: 0 0.75rem 0 0.5rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

code {
    font-family: var(--font-mono);
    font-size: 0.95rem;
    color: #d4d4d4;
    line-height: 1.6;
}

p code,
li code {
    background-color: rgba(129, 140, 248, 0.15);
    padding: 0.2rem 0.5rem;
    border-radius: 0.375rem;
    font-size: 0.9em;
    color: var(--accent-primary);
    border: 1px solid rgba(129, 140, 248, 0.25);
    transition: all 0.2s;
}

p code:hover,
li code:hover {
    background-color: rgba(129, 140, 248, 0.25);
    border-color: rgba(129, 140, 248, 0.4);
}

/* Copy button styling */
.code-container {
    position: relative;
}

.copy-btn {
    position: absolute;
    top: 0.5rem;
    right: 0.5rem;
    padding: 0.35rem 0.75rem;
    background: rgba(255, 255, 255, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: 0.375rem;
    color: #e2e8f0;
    cursor: pointer;
    font-size: 0.8rem;
    font-family: var(--font-sans);
    transition: all 0.2s var(--transition-smooth);
    z-index: 10;
}

.copy-btn:hover {
    background: rgba(255, 255, 255, 0.2);
    transform: translateY(-1px);
}

.copy-btn.copied {
    background: rgba(74, 222, 128, 0.2);
    border-color: var(--success);
    color: var(--success);
}

/* ========================================
   DIAGRAMS/VISUALS
   ======================================== */

.diagram {
    background: linear-gradient(135deg, var(--bg-secondary) 0%, var(--bg-tertiary) 100%);
    border: 2px solid var(--border-color);
    border-radius: 1rem;
    padding: 2.5rem;
    margin: 3rem 0;
    text-align: center;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.3);
    transition: all 0.4s var(--transition-smooth);
    position: relative;
    overflow: hidden;
}

.diagram::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: radial-gradient(circle at center, rgba(129, 140, 248, 0.05) 0%, transparent 70%);
    pointer-events: none;
}

.diagram:hover {
    border-color: var(--accent-primary);
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.4), var(--glow-primary);
    transform: translateY(-4px);
}

.diagram img {
    transition: transform 0.4s var(--transition-smooth);
}

.diagram:hover img {
    transform: scale(1.02);
}

.diagram img,
.diagram svg {
    max-width: 100%;
    height: auto;
    border-radius: 0.5rem;
    position: relative;
}

.diagram figcaption,
.diagram p {
    margin-top: 1.5rem;
    color: var(--text-secondary);
    font-size: 0.95rem;
    font-style: italic;
}

/* ========================================
   INFO & WARNING BOXES
   ======================================== */

.intro-note,
.info-box {
    background: linear-gradient(135deg, var(--bg-secondary) 0%, rgba(129, 140, 248, 0.05) 100%);
    border-left: 4px solid var(--accent-primary);
    padding: 1.5rem;
    margin-bottom: 2rem;
    border-radius: 0 0.75rem 0.75rem 0;
    transition: all 0.3s var(--transition-smooth);
}

.intro-note:hover,
.info-box:hover {
    border-left-width: 6px;
    transform: translateX(2px);
}

.warning-box {
    background: linear-gradient(135deg, rgba(239, 68, 68, 0.05) 0%, rgba(239, 68, 68, 0.1) 100%);
    border-left: 4px solid #ef4444;
    padding: 1rem;
    margin: 1.5rem 0;
    border-radius: 0 0.75rem 0.75rem 0;
    transition: all 0.3s var(--transition-smooth);
}

.warning-box:hover {
    border-left-width: 6px;
}

/* ========================================
   TABLES
   ======================================== */

table {
    width: 100%;
    border-collapse: collapse;
    margin: 1.5rem 0;
    background: var(--bg-secondary);
    border-radius: 0.75rem;
    overflow: hidden;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
}

th {
    background: var(--bg-tertiary);
    padding: 1rem;
    text-align: left;
    font-weight: 600;
    color: var(--accent-primary);
    border-bottom: 2px solid var(--accent-primary);
}

td {
    padding: 0.75rem 1rem;
    border-bottom: 1px solid var(--border-color);
    color: var(--text-secondary);
}

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

tr:hover td {
    background: rgba(129, 140, 248, 0.05);
}

/* ========================================
   FOOTER
   ======================================== */

footer {
    background: linear-gradient(to top, var(--bg-secondary), var(--bg-primary));
    padding: 4rem 0;
    margin-top: 4rem;
    border-top: 1px solid var(--border-color);
    text-align: center;
    color: var(--text-secondary);
}

/* ========================================
   TABLE OF CONTENTS SIDEBAR
   ======================================== */

.toc-container {
    display: none;
}

@media (min-width: 1400px) {
    .page-with-toc {
        display: grid;
        grid-template-columns: 1fr 900px 280px;
        gap: 2rem;
        max-width: 1400px;
        margin: 0 auto;
    }

    .page-with-toc::before {
        content: '';
    }

    .toc-container {
        display: block;
        position: sticky;
        top: 100px;
        height: fit-content;
        padding: 1.5rem;
        background: var(--glass-bg);
        backdrop-filter: blur(10px);
        border: 1px solid var(--border-color);
        border-radius: 0.75rem;
        margin-top: 4rem;
        transition: all 0.3s var(--transition-smooth);
    }

    .toc-container:hover {
        border-color: rgba(129, 140, 248, 0.3);
        box-shadow: 0 4px 20px rgba(0, 0, 0, 0.2);
    }

    .toc-container h4 {
        font-size: 0.85rem;
        text-transform: uppercase;
        letter-spacing: 0.1em;
        color: var(--text-muted);
        margin-bottom: 1rem;
    }

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

    .toc-container li {
        margin-bottom: 0.5rem;
    }

    .toc-container a {
        display: block;
        padding: 0.5rem 0.75rem;
        font-size: 0.9rem;
        color: var(--text-secondary);
        border-left: 2px solid transparent;
        border-radius: 0 0.25rem 0.25rem 0;
        transition: all 0.2s;
    }

    .toc-container a:hover {
        color: var(--accent-primary);
        background: rgba(129, 140, 248, 0.1);
    }

    .toc-container a.active {
        color: var(--accent-primary);
        border-left-color: var(--accent-primary);
        background: rgba(129, 140, 248, 0.1);
    }
}

/* ========================================
   SYNTAX HIGHLIGHTING
   ======================================== */

.token.comment {
    color: #6272a4;
}

.token.keyword {
    color: #ff79c6;
}

.token.string {
    color: #f1fa8c;
}

.token.number {
    color: #bd93f9;
}

.token.function {
    color: #50fa7b;
}

.token.type {
    color: #8be9fd;
}

/* ========================================
   RESPONSIVE DESIGN
   ======================================== */

@media (max-width: 1024px) {
    .content-wrapper {
        padding: 3rem 1.5rem;
    }

    .content-block {
        padding: 2rem 1.5rem;
    }

    .content-block h2 {
        font-size: 2rem;
    }

    .content-block h3 {
        font-size: 1.5rem;
    }
}

@media (max-width: 768px) {
    .hero h1 {
        font-size: 2.5rem;
    }

    .hero {
        padding: 5rem 0 4rem;
    }

    .nav-links {
        display: none;
    }

    .mobile-menu-btn {
        display: block;
    }

    .mobile-nav {
        display: block;
    }

    .nav-overlay {
        display: block;
    }

    .content-wrapper {
        padding: 2rem 1rem;
    }

    .content-block {
        padding: 1.5rem 1rem;
        margin-bottom: 2rem;
    }

    .content-block h2 {
        font-size: 1.75rem;
        margin-bottom: 1.25rem;
    }

    .content-block h3 {
        font-size: 1.35rem;
        margin-top: 2rem;
    }

    .content-block p,
    .content-block li {
        font-size: 1rem;
    }

    pre {
        padding: 1.25rem;
        font-size: 0.85rem;
        border-radius: 0.5rem;
    }

    .diagram {
        padding: 1.5rem 1rem;
        margin: 2rem 0;
    }

    .cta-buttons {
        flex-direction: column;
        width: 100%;
        padding: 0 1rem;
    }

    .btn {
        width: 100%;
        text-align: center;
    }

    .grid {
        gap: 1.5rem;
    }

    .card {
        padding: 1.5rem;
    }

    .scroll-top-btn {
        bottom: 1.5rem;
        right: 1.5rem;
        width: 42px;
        height: 42px;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 1rem;
    }

    .hero h1 {
        font-size: 2rem;
    }

    .section-title {
        font-size: 1.75rem;
    }

    .card h3 {
        font-size: 1.25rem;
    }
}

/* ========================================
   ANIMATIONS & TRANSITIONS
   ======================================== */

@keyframes pulse {

    0%,
    100% {
        opacity: 1;
    }

    50% {
        opacity: 0.7;
    }
}

@keyframes slideInRight {
    from {
        transform: translateX(100%);
    }

    to {
        transform: translateX(0);
    }
}

/* Prevent body scroll when mobile menu is open */
body.menu-open {
    overflow: hidden;
}

/* Focus styles for accessibility */
:focus-visible {
    outline: 2px solid var(--accent-primary);
    outline-offset: 2px;
}

button:focus-visible,
a:focus-visible {
    outline: 2px solid var(--accent-primary);
    outline-offset: 2px;
}

/* Selection styling */
::selection {
    background: rgba(129, 140, 248, 0.3);
    color: white;
}

/* ========================================
   ENHANCED TOOLTIPS
   ======================================== */

.tooltip {
    position: relative;
    cursor: help;
    border-bottom: 1px dotted var(--accent-primary);
}

.tooltip::before {
    content: attr(data-tooltip);
    position: absolute;
    bottom: 100%;
    left: 50%;
    transform: translateX(-50%) translateY(-8px);
    padding: 0.75rem 1rem;
    background: var(--bg-tertiary);
    color: var(--text-primary);
    font-size: 0.85rem;
    font-weight: 400;
    line-height: 1.5;
    border-radius: 0.5rem;
    border: 1px solid var(--border-color);
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.4);
    white-space: nowrap;
    max-width: 300px;
    white-space: normal;
    opacity: 0;
    visibility: hidden;
    transition: all 0.2s var(--transition-smooth);
    z-index: 100;
    pointer-events: none;
}

.tooltip::after {
    content: '';
    position: absolute;
    bottom: 100%;
    left: 50%;
    transform: translateX(-50%) translateY(4px);
    border: 6px solid transparent;
    border-top-color: var(--bg-tertiary);
    opacity: 0;
    visibility: hidden;
    transition: all 0.2s var(--transition-smooth);
    z-index: 100;
}

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

.tooltip:hover::before {
    transform: translateX(-50%) translateY(-12px);
}

.tooltip:hover::after {
    transform: translateX(-50%) translateY(0);
}

/* ========================================
   STEP INDICATORS & NUMBERED LISTS
   ======================================== */

.steps-list {
    counter-reset: step-counter;
    list-style: none;
    padding-left: 0;
}

.steps-list li {
    counter-increment: step-counter;
    position: relative;
    padding-left: 4rem;
    margin-bottom: 2rem;
    padding-bottom: 2rem;
    border-left: 2px solid var(--border-color);
}

.steps-list li::before {
    content: counter(step-counter);
    position: absolute;
    left: -1.25rem;
    top: 0;
    width: 2.5rem;
    height: 2.5rem;
    background: var(--accent-gradient);
    color: white;
    font-weight: 700;
    font-size: 1rem;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 4px 12px rgba(129, 140, 248, 0.4);
}

.steps-list li:last-child {
    border-left-color: transparent;
    padding-bottom: 0;
    margin-bottom: 0;
}

/* ========================================
   KEY TERM HIGHLIGHTS
   ======================================== */

.key-term {
    background: linear-gradient(135deg, rgba(129, 140, 248, 0.1) 0%, rgba(192, 132, 252, 0.1) 100%);
    padding: 0.15rem 0.5rem;
    border-radius: 0.25rem;
    font-weight: 600;
    color: var(--accent-primary);
    border: 1px solid rgba(129, 140, 248, 0.2);
    transition: all 0.2s;
}

.key-term:hover {
    background: linear-gradient(135deg, rgba(129, 140, 248, 0.2) 0%, rgba(192, 132, 252, 0.2) 100%);
    border-color: rgba(129, 140, 248, 0.4);
}

/* ========================================
   CONCEPT CARDS
   ======================================== */

.concept-card {
    background: linear-gradient(135deg, var(--bg-secondary) 0%, var(--bg-tertiary) 100%);
    border: 1px solid var(--border-color);
    border-radius: 1rem;
    padding: 1.5rem;
    margin: 1.5rem 0;
    position: relative;
    overflow: hidden;
    transition: all 0.3s var(--transition-smooth);
}

.concept-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 4px;
    height: 100%;
    background: var(--accent-gradient);
}

.concept-card:hover {
    transform: translateX(4px);
    border-color: var(--accent-primary);
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.3);
}

.concept-card h4 {
    color: var(--accent-primary);
    margin-bottom: 0.75rem;
    font-size: 1.1rem;
}

.concept-card p {
    margin-bottom: 0;
    color: var(--text-secondary);
}

/* ========================================
   COMPARISON BOXES
   ======================================== */

.comparison-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.5rem;
    margin: 2rem 0;
}

.comparison-box {
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 0.75rem;
    padding: 1.5rem;
    position: relative;
    transition: all 0.3s var(--transition-smooth);
}

.comparison-box.producer {
    border-top: 3px solid var(--success);
}

.comparison-box.consumer {
    border-top: 3px solid var(--warning);
}

.comparison-box.mutex {
    border-top: 3px solid var(--accent-primary);
}

.comparison-box:hover {
    transform: translateY(-4px);
    box-shadow: 0 12px 28px rgba(0, 0, 0, 0.3);
}

.comparison-box h4 {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    margin-bottom: 1rem;
}

.comparison-box.producer h4 {
    color: var(--success);
}

.comparison-box.consumer h4 {
    color: var(--warning);
}

.comparison-box.mutex h4 {
    color: var(--accent-primary);
}

/* ========================================
   ENHANCED LIST STYLES
   ======================================== */

.content-block ul.feature-list {
    list-style: none;
    padding-left: 0;
}

.content-block ul.feature-list li {
    position: relative;
    padding-left: 2rem;
    margin-bottom: 1rem;
}

.content-block ul.feature-list li::before {
    content: '✓';
    position: absolute;
    left: 0;
    top: 0;
    color: var(--success);
    font-weight: 700;
    font-size: 1.1rem;
}

.content-block ul.warning-list {
    list-style: none;
    padding-left: 0;
}

.content-block ul.warning-list li {
    position: relative;
    padding-left: 2rem;
    margin-bottom: 1rem;
}

.content-block ul.warning-list li::before {
    content: '⚠';
    position: absolute;
    left: 0;
    top: 0;
    color: var(--warning);
    font-size: 1rem;
}

/* ========================================
   CALLOUT BOXES
   ======================================== */

.callout {
    padding: 1.5rem;
    border-radius: 0.75rem;
    margin: 2rem 0;
    position: relative;
    overflow: hidden;
}

.callout::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 4px;
    height: 100%;
}

.callout-info {
    background: linear-gradient(135deg, rgba(129, 140, 248, 0.08) 0%, rgba(129, 140, 248, 0.15) 100%);
    border: 1px solid rgba(129, 140, 248, 0.3);
}

.callout-info::before {
    background: var(--accent-primary);
}

.callout-success {
    background: linear-gradient(135deg, rgba(74, 222, 128, 0.08) 0%, rgba(74, 222, 128, 0.15) 100%);
    border: 1px solid rgba(74, 222, 128, 0.3);
}

.callout-success::before {
    background: var(--success);
}

.callout-warning {
    background: linear-gradient(135deg, rgba(251, 191, 36, 0.08) 0%, rgba(251, 191, 36, 0.15) 100%);
    border: 1px solid rgba(251, 191, 36, 0.3);
}

.callout-warning::before {
    background: var(--warning);
}

.callout-danger {
    background: linear-gradient(135deg, rgba(248, 113, 113, 0.08) 0%, rgba(248, 113, 113, 0.15) 100%);
    border: 1px solid rgba(248, 113, 113, 0.3);
}

.callout-danger::before {
    background: var(--danger);
}

.callout-title {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-weight: 600;
    margin-bottom: 0.75rem;
}

.callout-info .callout-title {
    color: var(--accent-primary);
}

.callout-success .callout-title {
    color: var(--success);
}

.callout-warning .callout-title {
    color: var(--warning);
}

.callout-danger .callout-title {
    color: var(--danger);
}

/* ========================================
   BREADCRUMB NAVIGATION
   ======================================== */

.breadcrumb {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 1rem 0;
    font-size: 0.9rem;
    color: var(--text-muted);
    flex-wrap: wrap;
}

.breadcrumb a {
    color: var(--text-secondary);
    transition: color 0.2s;
}

.breadcrumb a:hover {
    color: var(--accent-primary);
}

.breadcrumb-separator {
    color: var(--text-muted);
}

.breadcrumb-current {
    color: var(--accent-primary);
    font-weight: 500;
}

/* ========================================
   READING PROGRESS
   ======================================== */

.reading-time {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 1rem;
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 2rem;
    font-size: 0.85rem;
    color: var(--text-secondary);
    margin-bottom: 2rem;
}

.reading-time svg {
    width: 16px;
    height: 16px;
    fill: var(--accent-primary);
}

/* ========================================
   ENHANCED DIAGRAM CAPTIONS
   ======================================== */

.diagram figcaption {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    margin-top: 1.5rem;
    padding-top: 1rem;
    border-top: 1px solid var(--border-color);
}

.diagram figcaption::before {
    content: '📊';
    font-size: 1rem;
}

/* ========================================
   CODE BLOCK ENHANCEMENTS
   ======================================== */

.code-filename {
    display: inline-block;
    padding: 0.35rem 1rem;
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-bottom: none;
    border-radius: 0.5rem 0.5rem 0 0;
    font-family: var(--font-mono);
    font-size: 0.8rem;
    color: var(--text-secondary);
    margin-bottom: -2px;
    position: relative;
    z-index: 1;
}

.code-filename+pre {
    border-top-left-radius: 0;
    margin-top: 0;
}

/* Line numbers for code blocks */
pre.line-numbers {
    padding-left: 3.5rem;
    position: relative;
}

pre.line-numbers::before {
    content: attr(data-line-numbers);
    position: absolute;
    left: 0;
    top: 0;
    bottom: 0;
    width: 3rem;
    padding: 1.75rem 0.5rem;
    background: rgba(0, 0, 0, 0.2);
    border-right: 1px solid var(--border-color);
    color: var(--text-muted);
    font-size: 0.85rem;
    line-height: 1.6;
    text-align: right;
    user-select: none;
    white-space: pre-line;
}

/* ========================================
   KEYBOARD SHORTCUTS
   ======================================== */

kbd {
    display: inline-block;
    padding: 0.2rem 0.5rem;
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: 0.25rem;
    font-family: var(--font-mono);
    font-size: 0.85em;
    color: var(--text-primary);
    box-shadow: 0 2px 0 var(--bg-primary), 0 3px 0 var(--border-color);
}

/* ========================================
   TERMINAL OUTPUT STYLING
   ======================================== */

.terminal-output {
    background: #000;
    border: 1px solid #333;
    border-radius: 0.75rem;
    overflow: hidden;
    margin: 1.5rem 0;
}

.terminal-header {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1rem;
    background: #1a1a1a;
    border-bottom: 1px solid #333;
}

.terminal-dot {
    width: 12px;
    height: 12px;
    border-radius: 50%;
}

.terminal-dot.red {
    background: #ff5f56;
}

.terminal-dot.yellow {
    background: #ffbd2e;
}

.terminal-dot.green {
    background: #27ca40;
}

.terminal-title {
    margin-left: 0.5rem;
    font-family: var(--font-mono);
    font-size: 0.8rem;
    color: #888;
}

.terminal-body {
    padding: 1rem;
    font-family: var(--font-mono);
    font-size: 0.9rem;
    color: #0f0;
    line-height: 1.6;
    white-space: pre-wrap;
}

.terminal-body .prompt {
    color: #0af;
}

.terminal-body .command {
    color: #fff;
}

.terminal-body .output {
    color: #888;
}

.terminal-body .comment {
    color: #6a9955;
}

/* ========================================
   SMOOTH SCROLL ANCHORS
   ======================================== */

[id] {
    scroll-margin-top: 100px;
}

/* ========================================
   PRINT STYLES
   ======================================== */

@media print {

    .scroll-progress,
    .scroll-top-btn,
    .mobile-menu-btn,
    .mobile-nav,
    .nav-overlay,
    .copy-btn,
    .toc-container {
        display: none !important;
    }

    header {
        position: static;
        background: white;
        border-bottom: 1px solid #ddd;
    }

    body {
        background: white;
        color: black;
    }

    .content-block h2,
    .content-block h3 {
        color: black;
        border-color: #333;
    }

    .diagram {
        break-inside: avoid;
        page-break-inside: avoid;
    }

    pre {
        break-inside: avoid;
        page-break-inside: avoid;
        border: 1px solid #ddd;
    }
}

/* ========================================
   REDUCED MOTION SUPPORT
   ======================================== */

@media (prefers-reduced-motion: reduce) {

    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }

    html {
        scroll-behavior: auto;
    }
}
/* Ensure background colors print */
@media print {
    body {
        -webkit-print-color-adjust: exact;
        print-color-adjust: exact;
    }
}