/* ===== Reset & Base ===== */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

:root {
    /* Colors - Dark Theme */
    --bg-primary: #0d1117;
    --bg-secondary: #161b22;
    --bg-tertiary: #21262d;
    --bg-card: #1c2128;
    
    --text-primary: #c9d1d9;
    --text-secondary: #8b949e;
    --text-muted: #6e7681;
    
    --accent-primary: #58a6ff;
    --accent-secondary: #79c0ff;
    --accent-success: #3fb950;
    --accent-warning: #d29922;
    --accent-danger: #f85149;
    
    --border-color: #30363d;
    
    /* Terminal Colors */
    --term-bg: #1e1e1e;
    --term-green: #4ec9b0;
    --term-yellow: #dcdcaa;
    --term-blue: #569cd6;
    --term-red: #f44747;
    --term-purple: #c586c0;
    --term-orange: #ce9178;
    
    /* Spacing */
    --space-xs: 0.25rem;
    --space-sm: 0.5rem;
    --space-md: 1rem;
    --space-lg: 1.5rem;
    --space-xl: 2rem;
    --space-2xl: 3rem;
    --space-3xl: 4rem;
    
    /* Typography */
    --font-mono: 'Fira Code', 'Monaco', 'Consolas', monospace;
    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    
    /* Transitions */
    --transition-fast: 0.15s ease;
    --transition-normal: 0.3s ease;
    --transition-slow: 0.5s ease;
    
    /* Shadows */
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 10px 25px rgba(0, 0, 0, 0.5);
    --shadow-glow: 0 0 20px rgba(88, 166, 255, 0.3);
}

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;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--space-lg);
}

/* ===== Navigation ===== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(13, 17, 23, 0.9);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border-color);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: var(--space-md) var(--space-lg);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
}

.logo-icon {
    font-family: var(--font-mono);
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--accent-primary);
    text-shadow: 0 0 10px rgba(88, 166, 255, 0.5);
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: var(--space-xl);
}

.nav-link {
    color: var(--text-secondary);
    text-decoration: none;
    font-weight: 500;
    transition: color var(--transition-fast);
    position: relative;
}

.nav-link:hover {
    color: var(--text-primary);
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--accent-primary);
    transition: width var(--transition-fast);
}

.nav-link:hover::after {
    width: 100%;
}

.hamburger {
    display: none;
    flex-direction: column;
    gap: 5px;
    cursor: pointer;
}

.hamburger span {
    width: 25px;
    height: 2px;
    background: var(--text-primary);
    transition: var(--transition-fast);
}

/* ===== Hero Section ===== */
.hero {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    position: relative;
    padding: var(--space-3xl) var(--space-lg);
    overflow: hidden;
}

.hero-background {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0.3;
    pointer-events: none;
}

.terminal-animation {
    transform: scale(1.5);
}

.terminal-window {
    background: var(--term-bg);
    border-radius: 8px;
    box-shadow: var(--shadow-lg);
    overflow: hidden;
    width: 500px;
    max-width: 90vw;
}

.terminal-header {
    background: #323232;
    padding: var(--space-sm) var(--space-md);
    display: flex;
    align-items: center;
    gap: var(--space-md);
}

.terminal-buttons {
    display: flex;
    gap: 8px;
}

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

.btn.close { background: #ff5f56; }
.btn.minimize { background: #ffbd2e; }
.btn.maximize { background: #27c93f; }

.terminal-title {
    flex: 1;
    text-align: center;
    font-family: var(--font-mono);
    font-size: 0.8rem;
    color: var(--text-secondary);
}

.terminal-body {
    padding: var(--space-md);
    font-family: var(--font-mono);
    font-size: 0.9rem;
    min-height: 150px;
}

.terminal-line {
    display: flex;
    gap: var(--space-sm);
    margin-bottom: var(--space-sm);
}

.prompt {
    color: var(--accent-success);
}

.command {
    color: var(--text-primary);
}

.command.typing::after {
    content: '|';
    animation: blink 1s infinite;
}

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

.hidden {
    opacity: 0;
}

@keyframes blink {
    0%, 50% { opacity: 1; }
    51%, 100% { opacity: 0; }
}

.hero-content {
    position: relative;
    z-index: 1;
    text-align: center;
    max-width: 800px;
}

.hero-title {
    font-size: clamp(2.5rem, 8vw, 4.5rem);
    font-weight: 700;
    margin-bottom: var(--space-lg);
    line-height: 1.2;
}

.hero-title .highlight {
    background: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: clamp(1rem, 3vw, 1.25rem);
    color: var(--text-secondary);
    margin-bottom: var(--space-2xl);
    line-height: 1.8;
}

.hero-subtitle strong {
    color: var(--accent-primary);
}

.hero-buttons {
    display: flex;
    gap: var(--space-md);
    justify-content: center;
    flex-wrap: wrap;
}

.btn-primary, .btn-secondary {
    display: inline-flex;
    align-items: center;
    gap: var(--space-sm);
    padding: var(--space-md) var(--space-xl);
    border-radius: 8px;
    font-weight: 600;
    text-decoration: none;
    transition: all var(--transition-fast);
}

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

.btn-primary:hover {
    background: var(--accent-secondary);
    transform: translateY(-2px);
    box-shadow: var(--shadow-glow);
}

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

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

.arrow {
    width: 20px;
    height: 20px;
    transition: transform var(--transition-fast);
}

.btn-primary:hover .arrow {
    transform: translateX(4px);
}

/* ===== Section Headers ===== */
.section-header {
    text-align: center;
    margin-bottom: var(--space-3xl);
}

.badge {
    display: inline-block;
    padding: var(--space-xs) var(--space-md);
    background: var(--bg-tertiary);
    color: var(--accent-primary);
    border-radius: 20px;
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin-bottom: var(--space-md);
}

.section-header h2 {
    font-size: clamp(1.75rem, 5vw, 2.5rem);
    margin-bottom: var(--space-md);
}

.section-header p {
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto;
}

/* ===== What is tmux ===== */
.what-is-tmux {
    padding: var(--space-3xl) 0;
    background: var(--bg-secondary);
}

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

.feature-card {
    background: var(--bg-card);
    padding: var(--space-xl);
    border-radius: 12px;
    border: 1px solid var(--border-color);
    transition: all var(--transition-normal);
}

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

.feature-icon {
    width: 48px;
    height: 48px;
    background: var(--bg-tertiary);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: var(--space-lg);
}

.feature-icon svg {
    width: 24px;
    height: 24px;
    stroke: var(--accent-primary);
}

.feature-card h3 {
    font-size: 1.25rem;
    margin-bottom: var(--space-sm);
}

.feature-card p {
    color: var(--text-secondary);
}

/* ===== Concepts Section ===== */
.concepts-section {
    padding: var(--space-3xl) 0;
}

.hierarchy-visualization {
    margin-bottom: var(--space-3xl);
}

/* New Flow Layout */
.hierarchy-flow {
    display: flex;
    align-items: stretch;
    justify-content: center;
    gap: var(--space-lg);
    flex-wrap: wrap;
    margin-bottom: var(--space-2xl);
}

@media (max-width: 1200px) {
    .hierarchy-flow {
        flex-direction: column;
        align-items: center;
    }
    
    .hierarchy-arrow {
        transform: rotate(90deg);
    }
}

/* Hierarchy Cards */
.hierarchy-card {
    background: var(--bg-card);
    border: 2px solid var(--border-color);
    border-radius: 16px;
    padding: var(--space-xl);
    min-width: 320px;
    max-width: 380px;
    transition: all var(--transition-normal);
    position: relative;
    overflow: hidden;
}

.hierarchy-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    transition: background var(--transition-normal);
}

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

.session-card::before {
    background: linear-gradient(90deg, #58a6ff, #79c0ff);
}

.session-card {
    border-color: #58a6ff;
}

.session-card:hover {
    border-color: #79c0ff;
    box-shadow: 0 10px 30px rgba(88, 166, 255, 0.2);
}

.window-card::before {
    background: linear-gradient(90deg, #3fb950, #56d364);
}

.window-card {
    border-color: #3fb950;
}

.window-card:hover {
    border-color: #56d364;
    box-shadow: 0 10px 30px rgba(63, 185, 80, 0.2);
}

.pane-card::before {
    background: linear-gradient(90deg, #d29922, #e3b341);
}

.pane-card {
    border-color: #d29922;
}

.pane-card:hover {
    border-color: #e3b341;
    box-shadow: 0 10px 30px rgba(210, 153, 34, 0.2);
}

/* Card Header */
.card-header {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    margin-bottom: var(--space-lg);
    padding-bottom: var(--space-md);
    border-bottom: 1px solid var(--border-color);
}

.card-header h3 {
    font-size: 1.1rem;
    flex: 1;
}

.level-badge {
    width: 32px;
    height: 32px;
    background: var(--accent-primary);
    color: var(--bg-primary);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 0.9rem;
}

.window-card .level-badge {
    background: var(--accent-success);
}

.pane-card .level-badge {
    background: var(--accent-warning);
}

.level-desc {
    font-size: 0.75rem;
    color: var(--text-muted);
    background: var(--bg-tertiary);
    padding: 4px 10px;
    border-radius: 20px;
}

/* Card Body */
.card-body {
    display: flex;
    flex-direction: column;
    gap: var(--space-md);
}

/* Session Card */
.session-example {
    background: var(--bg-tertiary);
    padding: var(--space-md);
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.session-name {
    font-family: var(--font-mono);
    color: var(--accent-primary);
    font-weight: 500;
}

.session-icon {
    font-size: 1.5rem;
}

.session-info p,
.window-info p,
.pane-info p {
    color: var(--text-secondary);
    font-size: 0.9rem;
    text-align: center;
}

/* Window Card */
.window-tabs-preview {
    display: flex;
    flex-direction: column;
    gap: var(--space-xs);
}

.tab-item {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    padding: var(--space-sm) var(--space-md);
    background: var(--bg-tertiary);
    border-radius: 8px;
    border: 1px solid transparent;
    transition: all var(--transition-fast);
}

.tab-item.active {
    background: rgba(63, 185, 80, 0.2);
    border-color: var(--accent-success);
}

.tab-icon {
    font-size: 1rem;
}

.tab-name {
    font-family: var(--font-mono);
    font-size: 0.85rem;
    color: var(--text-primary);
}

/* Pane Card */
.pane-preview {
    display: grid;
    grid-template-columns: 1fr 2px 1fr;
    gap: 0;
    background: var(--bg-tertiary);
    border-radius: 8px;
    overflow: hidden;
    min-height: 140px;
}

.mini-pane-left,
.mini-pane-right {
    padding: var(--space-sm);
    font-size: 0.75rem;
}

.mini-pane-header {
    font-size: 0.7rem;
    color: var(--text-muted);
    background: var(--bg-primary);
    padding: 2px 8px;
    border-radius: 4px;
    margin-bottom: var(--space-sm);
    display: inline-block;
}

.mini-pane-content {
    font-family: var(--font-mono);
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.mini-pane-content code {
    color: var(--term-blue);
    background: none;
    padding: 0;
}

.mini-pane-content span {
    color: var(--text-secondary);
}

.success-text {
    color: var(--accent-success) !important;
}

.mini-pane-divider {
    background: var(--border-color);
    width: 2px;
}

.cursor-blink {
    animation: blink 1s infinite;
    color: var(--accent-primary);
}

/* Hierarchy Arrow */
.hierarchy-arrow {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    color: var(--text-muted);
    gap: var(--space-xs);
}

.hierarchy-arrow svg {
    width: 24px;
    height: 24px;
    stroke-width: 2;
}

.arrow-label {
    font-size: 0.75rem;
    background: var(--bg-tertiary);
    padding: 2px 10px;
    border-radius: 20px;
    white-space: nowrap;
}

/* Summary */
.hierarchy-summary {
    text-align: center;
}

.summary-box {
    background: linear-gradient(135deg, rgba(88, 166, 255, 0.1), rgba(63, 185, 80, 0.1), rgba(210, 153, 34, 0.1));
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: var(--space-lg) var(--space-xl);
    display: inline-block;
    max-width: 600px;
}

.summary-box h4 {
    color: var(--accent-primary);
    margin-bottom: var(--space-sm);
    font-size: 1.1rem;
}

.summary-box p {
    color: var(--text-secondary);
    line-height: 1.8;
}

.summary-box strong {
    color: var(--text-primary);
    padding: 2px 6px;
    border-radius: 4px;
}

.summary-box strong:nth-of-type(1) {
    background: rgba(88, 166, 255, 0.2);
    color: #79c0ff;
}

.summary-box strong:nth-of-type(2) {
    background: rgba(63, 185, 80, 0.2);
    color: #56d364;
}

.summary-box strong:nth-of-type(3) {
    background: rgba(63, 185, 80, 0.2);
    color: #56d364;
}

.summary-box strong:nth-of-type(4) {
    background: rgba(210, 153, 34, 0.2);
    color: #e3b341;
}

/* Concepts Detail */
.concepts-detail {
    display: grid;
    gap: var(--space-xl);
}

.concept-card {
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: var(--space-xl);
    display: flex;
    gap: var(--space-xl);
    align-items: flex-start;
    transition: all var(--transition-normal);
}

.concept-card:hover {
    border-color: var(--accent-primary);
    background: var(--bg-card);
}

.concept-icon {
    width: 50px;
    height: 50px;
    background: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary));
    color: var(--bg-primary);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    font-weight: 700;
    flex-shrink: 0;
}

.concept-content {
    flex: 1;
}

.concept-content h3 {
    font-size: 1.25rem;
    margin-bottom: var(--space-sm);
    color: var(--accent-primary);
}

.concept-desc {
    color: var(--text-secondary);
    margin-bottom: var(--space-md);
}

.concept-demo {
    background: var(--bg-primary);
    border-radius: 8px;
    padding: var(--space-md);
    margin-bottom: var(--space-md);
}

.demo-code {
    font-family: var(--font-mono);
    font-size: 0.875rem;
}

.demo-line {
    margin-bottom: var(--space-xs);
}

.demo-line .comment {
    color: var(--text-muted);
}

.demo-line .cmd {
    color: var(--accent-primary);
}

.demo-line .arg {
    color: var(--term-orange);
}

.key-points {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-md);
}

.key-point {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    background: var(--bg-tertiary);
    padding: var(--space-sm) var(--space-md);
    border-radius: 6px;
}

.key-point .key {
    background: var(--bg-primary);
    padding: 2px 8px;
    border-radius: 4px;
    font-family: var(--font-mono);
    font-size: 0.8rem;
    border: 1px solid var(--border-color);
}

.key-point .desc {
    color: var(--text-secondary);
    font-size: 0.875rem;
}

/* ===== Pane Demo Section ===== */
.pane-demo-section {
    padding: var(--space-3xl) 0;
    background: var(--bg-secondary);
}

.demo-container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--space-3xl);
    align-items: center;
}

@media (max-width: 900px) {
    .demo-container {
        grid-template-columns: 1fr;
    }
}

.keyboard-section {
    display: flex;
    flex-direction: column;
    gap: var(--space-xl);
}

.instruction {
    background: var(--bg-card);
    padding: var(--space-md);
    border-radius: 8px;
    border-left: 4px solid var(--accent-primary);
}

.instruction p {
    color: var(--text-secondary);
}

.instruction kbd {
    background: var(--bg-tertiary);
    padding: 2px 8px;
    border-radius: 4px;
    font-family: var(--font-mono);
    font-size: 0.875rem;
}

.keyboard-visual {
    background: var(--bg-card);
    padding: var(--space-xl);
    border-radius: 12px;
    border: 1px solid var(--border-color);
}

.key-row {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-sm);
    justify-content: center;
}

.key {
    min-width: 50px;
    height: 50px;
    background: var(--bg-tertiary);
    border: 2px solid var(--border-color);
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-family: var(--font-mono);
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-fast);
    user-select: none;
}

.key:hover {
    border-color: var(--accent-primary);
    transform: translateY(-2px);
}

.key.active {
    background: var(--accent-primary);
    border-color: var(--accent-primary);
    color: var(--bg-primary);
    transform: translateY(2px);
    box-shadow: var(--shadow-glow);
}

.key.modifier {
    background: var(--bg-primary);
    border-color: var(--accent-primary);
    color: var(--accent-primary);
}

.key.arrow {
    font-size: 1.25rem;
}

.key-preview {
    margin-top: var(--space-lg);
    padding: var(--space-md);
    background: var(--bg-primary);
    border-radius: 8px;
    text-align: center;
    min-height: 50px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.pressed-keys {
    font-family: var(--font-mono);
    color: var(--accent-primary);
}

.terminal-preview {
    display: flex;
    justify-content: center;
}

.demo-terminal {
    width: 100%;
    max-width: 500px;
}

#demo-panes {
    min-height: 250px;
    display: grid;
    gap: 4px;
}

.pane-single {
    background: var(--bg-primary);
    border: 2px solid var(--accent-primary);
    border-radius: 6px;
    padding: var(--space-sm);
    position: relative;
    grid-column: 1 / -1;
    grid-row: 1 / -1;
}

.pane-horizontal {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4px;
}

.pane-vertical {
    display: grid;
    grid-template-rows: 1fr 1fr;
    gap: 4px;
}

.pane-four {
    display: grid;
    grid-template-columns: 1fr 1fr;
    grid-template-rows: 1fr 1fr;
    gap: 4px;
}

.demo-pane {
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: 4px;
    padding: var(--space-sm);
    position: relative;
}

.demo-pane.active {
    border-color: var(--accent-primary);
}

.status-bar {
    background: var(--bg-tertiary);
    padding: var(--space-xs) var(--space-md);
    display: flex;
    justify-content: space-between;
    font-size: 0.75rem;
    color: var(--text-secondary);
}

/* ===== Cheatsheet Section ===== */
.cheatsheet-section {
    padding: var(--space-3xl) 0;
}

.cheatsheet-filters {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-sm);
    justify-content: center;
    margin-bottom: var(--space-2xl);
}

.filter-btn {
    padding: var(--space-sm) var(--space-md);
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 20px;
    color: var(--text-secondary);
    font-size: 0.875rem;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.filter-btn:hover {
    border-color: var(--accent-primary);
    color: var(--text-primary);
}

.filter-btn.active {
    background: var(--accent-primary);
    border-color: var(--accent-primary);
    color: var(--bg-primary);
}

.cheatsheet-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: var(--space-xl);
}

.cheatsheet-category {
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    overflow: hidden;
}

.category-title {
    background: var(--bg-tertiary);
    padding: var(--space-md) var(--space-lg);
    font-size: 1rem;
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    border-bottom: 1px solid var(--border-color);
}

.category-icon {
    font-size: 1.25rem;
}

.commands-list {
    padding: var(--space-md);
}

.command-item {
    display: flex;
    align-items: center;
    gap: var(--space-md);
    padding: var(--space-md);
    border-radius: 8px;
    transition: all var(--transition-fast);
    position: relative;
}

.command-item:hover {
    background: var(--bg-card);
}

.command-item.highlight {
    background: rgba(88, 166, 255, 0.1);
    border: 1px solid var(--accent-primary);
}

.command-item.sub-item {
    padding-left: var(--space-xl);
    opacity: 0.8;
}

.command-item.sub-item::before {
    content: '└';
    position: absolute;
    left: var(--space-lg);
    color: var(--text-muted);
}

.command-keys {
    display: flex;
    align-items: center;
    gap: var(--space-xs);
    flex-shrink: 0;
}

.command-keys code {
    background: var(--bg-primary);
    padding: 4px 8px;
    border-radius: 4px;
    font-family: var(--font-mono);
    font-size: 0.8rem;
    color: var(--term-orange);
}

.command-keys kbd {
    background: var(--bg-primary);
    padding: 4px 8px;
    border-radius: 4px;
    font-family: var(--font-mono);
    font-size: 0.8rem;
    border: 1px solid var(--border-color);
}

.command-desc {
    color: var(--text-secondary);
    font-size: 0.875rem;
    flex: 1;
}

.copy-btn {
    background: transparent;
    border: none;
    color: var(--text-muted);
    cursor: pointer;
    padding: var(--space-xs);
    border-radius: 4px;
    transition: all var(--transition-fast);
    opacity: 0;
}

.command-item:hover .copy-btn {
    opacity: 1;
}

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

.copy-btn svg {
    width: 16px;
    height: 16px;
}

/* ===== Practice Section ===== */
.practice-section {
    padding: var(--space-3xl) 0;
    background: var(--bg-secondary);
}

.scenarios {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: var(--space-xl);
}

.scenario-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: var(--space-xl);
    transition: all var(--transition-normal);
}

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

.scenario-header {
    display: flex;
    align-items: center;
    gap: var(--space-md);
    margin-bottom: var(--space-lg);
}

.scenario-number {
    font-size: 2rem;
    font-weight: 700;
    color: var(--accent-primary);
    opacity: 0.5;
}

.scenario-header h3 {
    font-size: 1.25rem;
}

.scenario-visual {
    margin-bottom: var(--space-lg);
}

.mini-terminal {
    background: var(--term-bg);
    border-radius: 8px;
    padding: var(--space-md);
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    grid-template-rows: repeat(2, 60px);
    gap: 4px;
}

.mini-pane {
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: 4px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.mini-label {
    font-size: 0.75rem;
    color: var(--text-muted);
}

.scenario-steps {
    display: flex;
    flex-direction: column;
    gap: var(--space-md);
}

.step {
    display: flex;
    align-items: center;
    gap: var(--space-md);
    padding: var(--space-sm) 0;
    border-bottom: 1px solid var(--border-color);
}

.step:last-child {
    border-bottom: none;
}

.step code {
    background: var(--bg-tertiary);
    padding: 4px 8px;
    border-radius: 4px;
    font-family: var(--font-mono);
    font-size: 0.8rem;
    color: var(--term-orange);
}

.step kbd {
    background: var(--bg-tertiary);
    padding: 2px 6px;
    border-radius: 4px;
    font-family: var(--font-mono);
    font-size: 0.75rem;
}

.step span {
    color: var(--text-secondary);
    font-size: 0.875rem;
}

/* ===== Config Section ===== */
.config-section {
    padding: var(--space-3xl) 0;
}

.config-tabs {
    display: flex;
    gap: var(--space-sm);
    margin-bottom: var(--space-xl);
    flex-wrap: wrap;
}

.tab-btn {
    padding: var(--space-sm) var(--space-lg);
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    color: var(--text-secondary);
    font-size: 0.875rem;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.tab-btn:hover {
    border-color: var(--accent-primary);
    color: var(--text-primary);
}

.tab-btn.active {
    background: var(--accent-primary);
    border-color: var(--accent-primary);
    color: var(--bg-primary);
}

.config-content {
    margin-bottom: var(--space-3xl);
}

.tab-panel {
    display: none;
    animation: fadeIn 0.3s ease;
}

.tab-panel.active {
    display: block;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

.config-block {
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: var(--space-lg);
    margin-bottom: var(--space-lg);
    position: relative;
}

.config-block h4 {
    font-size: 1rem;
    margin-bottom: var(--space-md);
    color: var(--accent-primary);
}

.config-block pre {
    background: var(--bg-primary);
    padding: var(--space-md);
    border-radius: 8px;
    overflow-x: auto;
    margin-bottom: var(--space-md);
}

.config-block code {
    font-family: var(--font-mono);
    font-size: 0.875rem;
    color: var(--text-primary);
}

.copy-config-btn {
    position: absolute;
    top: var(--space-lg);
    right: var(--space-lg);
    padding: var(--space-xs) var(--space-md);
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: 4px;
    color: var(--text-secondary);
    font-size: 0.75rem;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.copy-config-btn:hover {
    background: var(--accent-primary);
    border-color: var(--accent-primary);
    color: var(--bg-primary);
}

.quick-start {
    background: linear-gradient(135deg, rgba(88, 166, 255, 0.1), rgba(121, 192, 255, 0.1));
    border: 1px solid var(--accent-primary);
    border-radius: 12px;
    padding: var(--space-xl);
}

.quick-start h3 {
    margin-bottom: var(--space-lg);
    color: var(--accent-primary);
}

.quick-steps {
    display: flex;
    flex-direction: column;
    gap: var(--space-md);
}

.quick-step {
    display: flex;
    align-items: center;
    gap: var(--space-md);
    font-size: 1rem;
}

.step-num {
    width: 32px;
    height: 32px;
    background: var(--accent-primary);
    color: var(--bg-primary);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 600;
}

.quick-step code {
    background: var(--bg-primary);
    padding: 4px 8px;
    border-radius: 4px;
    font-family: var(--font-mono);
}

.quick-step kbd {
    background: var(--bg-primary);
    padding: 2px 6px;
    border-radius: 4px;
    font-family: var(--font-mono);
    font-size: 0.875rem;
}

/* ===== Footer ===== */
.footer {
    background: var(--bg-secondary);
    border-top: 1px solid var(--border-color);
    padding: var(--space-3xl) 0 var(--space-xl);
}

.footer-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: var(--space-xl);
    margin-bottom: var(--space-xl);
    padding-bottom: var(--space-xl);
    border-bottom: 1px solid var(--border-color);
}

.footer-brand {
    display: flex;
    flex-direction: column;
    gap: var(--space-xs);
}

.footer-brand .logo-icon {
    font-size: 1.5rem;
}

.footer-brand p {
    color: var(--text-muted);
    font-size: 0.875rem;
}

.footer-links {
    display: flex;
    gap: var(--space-xl);
    flex-wrap: wrap;
}

.footer-links a {
    color: var(--text-secondary);
    text-decoration: none;
    transition: color var(--transition-fast);
}

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

.footer-bottom {
    text-align: center;
    color: var(--text-muted);
    font-size: 0.875rem;
}

/* ===== Toast ===== */
.toast {
    position: fixed;
    bottom: 30px;
    left: 50%;
    transform: translateX(-50%) translateY(100px);
    background: var(--accent-success);
    color: var(--bg-primary);
    padding: var(--space-md) var(--space-xl);
    border-radius: 8px;
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    font-weight: 600;
    box-shadow: var(--shadow-lg);
    opacity: 0;
    transition: all var(--transition-normal);
    z-index: 9999;
}

.toast.show {
    opacity: 1;
    transform: translateX(-50%) translateY(0);
}

/* ===== Responsive ===== */
@media (max-width: 768px) {
    .nav-menu {
        display: none;
    }
    
    .hamburger {
        display: flex;
    }
    
    .hero-buttons {
        flex-direction: column;
    }
    
    .btn-primary, .btn-secondary {
        width: 100%;
        justify-content: center;
    }
    
    .features-grid,
    .cheatsheet-grid,
    .scenarios {
        grid-template-columns: 1fr;
    }
    
    .concept-card {
        flex-direction: column;
    }
    
    .demo-container {
        grid-template-columns: 1fr;
    }
    
    .config-tabs {
        justify-content: center;
    }
    
    .footer-content {
        flex-direction: column;
        text-align: center;
    }
    
    .session-box {
        min-width: auto;
    }
    
    .pane-grid {
        grid-template-columns: 1fr;
    }
}

/* ===== Animations ===== */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.feature-card,
.concept-card,
.cheatsheet-category,
.scenario-card {
    animation: fadeInUp 0.6s ease forwards;
}

/* Scrollbar */
::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}

::-webkit-scrollbar-track {
    background: var(--bg-secondary);
}

::-webkit-scrollbar-thumb {
    background: var(--border-color);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--text-muted);
}

/* Selection */
::selection {
    background: rgba(88, 166, 255, 0.3);
    color: var(--text-primary);
}