/* ============================================
   Terminal Animation - Apple-Level Polish
   ============================================ */

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

:root {
    /* Colors - Terminal Theme */
    --bg-primary: #0a0e14;
    --bg-secondary: #0d1117;
    --bg-tertiary: #161b22;
    --bg-code: #1a1f26;
    --bg-elevated: #21262d;

    --text-primary: #c9d1d9;
    --text-secondary: #8b949e;
    --text-tertiary: #6e7681;
    --text-bright: #f0f6fc;

    --accent-primary: #00ff41;
    --accent-secondary: #39ff14;
    --accent-muted: #0a5f20;

    --border-subtle: #30363d;
    --border-default: #21262d;

    --terminal-bg: #0d1117;
    --terminal-text: #39ff14;

    /* Typography */
    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --font-mono: 'JetBrains Mono', 'SF Mono', Monaco, 'Cascadia Code', monospace;

    /* Spacing - Refined Scale */
    --space-xs: 0.5rem;
    --space-sm: 0.75rem;
    --space-md: 1rem;
    --space-lg: 1.5rem;
    --space-xl: 2rem;
    --space-2xl: 3rem;
    --space-3xl: 4rem;
    --space-4xl: 6rem;
    --space-5xl: 8rem;

    /* Layout */
    --nav-width: 280px;
    --content-max: 1400px;
    --content-narrow: 800px;

    /* Transitions */
    --ease-smooth: cubic-bezier(0.4, 0, 0.2, 1);
    --ease-bounce: cubic-bezier(0.68, -0.55, 0.265, 1.55);
    --duration-fast: 200ms;
    --duration-normal: 300ms;
    --duration-slow: 500ms;
}

html {
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-sans);
    color: var(--text-primary);
    background: var(--bg-primary);
    line-height: 1.7;
    overflow-x: hidden;
}

/* === MOBILE MENU TOGGLE === */
.menu-toggle {
    display: none;
    position: fixed;
    top: 1rem;
    left: 1rem;
    z-index: 1000;
    width: 44px;
    height: 44px;
    background: var(--bg-elevated);
    border: 1px solid var(--border-subtle);
    border-radius: 8px;
    cursor: pointer;
    align-items: center;
    justify-content: center;
    transition: all var(--duration-normal) var(--ease-smooth);
}

.menu-toggle:hover {
    background: var(--bg-tertiary);
    border-color: var(--accent-muted);
}

.menu-toggle-icon {
    width: 20px;
    height: 14px;
    position: relative;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
}

.menu-toggle-icon span {
    display: block;
    height: 2px;
    background: var(--accent-primary);
    border-radius: 2px;
    transition: all var(--duration-normal) var(--ease-smooth);
}

.menu-open .menu-toggle-icon span:nth-child(1) {
    transform: translateY(6px) rotate(45deg);
}

.menu-open .menu-toggle-icon span:nth-child(2) {
    opacity: 0;
}

.menu-open .menu-toggle-icon span:nth-child(3) {
    transform: translateY(-6px) rotate(-45deg);
}

/* === NAVIGATION === */
.nav {
    position: fixed;
    top: 0;
    left: 0;
    width: var(--nav-width);
    height: 100vh;
    background: var(--bg-secondary);
    border-right: 1px solid var(--border-subtle);
    overflow-y: auto;
    z-index: 100;
    padding: var(--space-2xl) 0;
    transition: transform var(--duration-normal) var(--ease-smooth);
}

.nav-header {
    padding: 0 var(--space-xl) var(--space-2xl);
    border-bottom: 1px solid var(--border-subtle);
    margin-bottom: var(--space-xl);
}

.nav-title {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--accent-primary);
    font-family: var(--font-mono);
    letter-spacing: -0.02em;
}

.nav-subtitle {
    font-size: 0.875rem;
    color: var(--text-tertiary);
    margin-top: var(--space-xs);
}

.nav-list {
    list-style: none;
    padding: 0 var(--space-lg);
}

.nav-list li {
    margin-bottom: var(--space-xs);
}

.nav-link {
    display: block;
    padding: var(--space-sm) var(--space-md);
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 0.9375rem;
    font-weight: 500;
    border-radius: 6px;
    transition: all var(--duration-fast) var(--ease-smooth);
    position: relative;
}

.nav-link:hover {
    color: var(--text-bright);
    background: var(--bg-elevated);
    transform: translateX(2px);
}

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

.nav-link.active::before {
    content: '';
    position: absolute;
    left: -var(--space-lg);
    top: 50%;
    transform: translateY(-50%);
    width: 3px;
    height: 60%;
    background: var(--accent-primary);
    border-radius: 0 3px 3px 0;
}

/* === MAIN CONTENT === */
.main {
    margin-left: var(--nav-width);
    min-height: 100vh;
}

/* === TYPOGRAPHY === */
h1 {
    font-size: clamp(2.5rem, 8vw, 5rem);
    font-weight: 700;
    letter-spacing: -0.04em;
    line-height: 1.05;
    color: var(--text-bright);
}

h2 {
    font-size: clamp(1.75rem, 5vw, 3rem);
    font-weight: 700;
    letter-spacing: -0.03em;
    line-height: 1.1;
    margin-bottom: var(--space-2xl);
    color: var(--text-bright);
}

h3 {
    font-size: clamp(1.25rem, 3vw, 1.75rem);
    font-weight: 600;
    line-height: 1.3;
    margin-bottom: var(--space-lg);
    margin-top: var(--space-2xl);
    color: var(--text-bright);
}

h4 {
    font-size: 1.125rem;
    font-weight: 600;
    line-height: 1.4;
    margin-bottom: var(--space-md);
    color: var(--accent-primary);
}

p {
    margin-bottom: var(--space-lg);
    color: var(--text-primary);
    font-size: 1.0625rem;
}

.lead {
    font-size: clamp(1.25rem, 2.5vw, 1.5rem);
    color: var(--text-secondary);
    line-height: 1.6;
    font-weight: 400;
    max-width: 48rem;
    margin: 0 auto;
}

.intro-text {
    font-size: clamp(1.125rem, 2.5vw, 1.25rem);
    line-height: 1.7;
    color: var(--text-primary);
    font-weight: 400;
}

.section-intro {
    font-size: 1.125rem;
    color: var(--text-secondary);
    margin-bottom: var(--space-2xl);
    max-width: 42rem;
}

strong {
    color: var(--text-bright);
    font-weight: 600;
}

code {
    font-family: var(--font-mono);
    font-size: 0.9em;
    background: var(--bg-code);
    padding: 0.2em 0.5em;
    border-radius: 4px;
    color: var(--accent-secondary);
}

/* === LAYOUT === */
.container {
    max-width: var(--content-max);
    margin: 0 auto;
    padding: 0 var(--space-2xl);
}

.container-narrow {
    max-width: var(--content-narrow);
    margin: 0 auto;
    padding: 0 var(--space-2xl);
}

.section {
    padding: var(--space-5xl) 0;
    position: relative;
    opacity: 0;
    transform: translateY(40px);
    transition: opacity var(--duration-slow) var(--ease-smooth),
                transform var(--duration-slow) var(--ease-smooth);
}

.section.visible {
    opacity: 1;
    transform: translateY(0);
}

.subsection {
    margin-bottom: var(--space-4xl);
}

.subsection:last-child {
    margin-bottom: 0;
}

/* === HERO === */
.hero {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: var(--space-4xl) 0;
    background: radial-gradient(ellipse at top, var(--bg-secondary), var(--bg-primary));
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle, rgba(0, 255, 65, 0.03) 0%, transparent 70%);
    animation: pulse 20s ease-in-out infinite;
}

@keyframes pulse {
    0%, 100% { transform: scale(1); opacity: 0.3; }
    50% { transform: scale(1.1); opacity: 0.5; }
}

.hero-content {
    max-width: 900px;
    margin: 0 auto var(--space-4xl);
    padding: 0 var(--space-2xl);
    text-align: center;
    position: relative;
    z-index: 1;
}

.hero h1 {
    margin-bottom: var(--space-xl);
    opacity: 0;
    animation: fadeInUp 1s var(--ease-smooth) forwards;
}

.hero .lead {
    opacity: 0;
    animation: fadeInUp 1s var(--ease-smooth) 0.2s forwards;
}

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

.hero-demo {
    max-width: 800px;
    margin: 0 auto;
    padding: 0 var(--space-2xl);
    position: relative;
    z-index: 1;
    opacity: 0;
    animation: fadeInUp 1s var(--ease-smooth) 0.4s forwards;
}

/* === SCROLL INDICATOR === */
.scroll-indicator {
    position: absolute;
    bottom: var(--space-3xl);
    left: 50%;
    transform: translateX(-50%);
    width: 24px;
    height: 40px;
    border: 2px solid var(--accent-muted);
    border-radius: 12px;
    display: flex;
    align-items: flex-start;
    justify-content: center;
    padding-top: 6px;
    cursor: pointer;
    opacity: 0;
    animation: fadeIn 1s var(--ease-smooth) 1s forwards;
}

.scroll-indicator::before {
    content: '';
    width: 4px;
    height: 8px;
    background: var(--accent-primary);
    border-radius: 2px;
    animation: scroll 2s ease-in-out infinite;
}

@keyframes scroll {
    0% { transform: translateY(0); opacity: 1; }
    100% { transform: translateY(16px); opacity: 0; }
}

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 0.6; }
}

/* === TERMINAL WINDOWS === */
.terminal-window {
    background: var(--terminal-bg);
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.5),
                0 8px 24px rgba(0, 0, 0, 0.4);
    border: 1px solid var(--border-default);
    transition: transform var(--duration-normal) var(--ease-smooth),
                box-shadow var(--duration-normal) var(--ease-smooth);
}

.terminal-window:hover {
    transform: translateY(-4px);
    box-shadow: 0 24px 70px rgba(0, 255, 65, 0.15),
                0 12px 32px rgba(0, 0, 0, 0.5);
}

.terminal-window.small {
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.4);
}

.terminal-window.small:hover {
    transform: translateY(-2px);
}

.terminal-header {
    background: var(--bg-tertiary);
    padding: 1rem 1.25rem;
    display: flex;
    align-items: center;
    gap: 0.75rem;
    border-bottom: 1px solid var(--border-default);
}

.dots {
    display: flex;
    gap: 0.5rem;
}

.dot {
    width: 12px;
    height: 12px;
    border-radius: 50%;
    transition: opacity var(--duration-fast) var(--ease-smooth);
}

.dot.red {
    background: #ff5f56;
}

.dot.yellow {
    background: #ffbd2e;
}

.dot.green {
    background: #27c93f;
}

.terminal-header:hover .dot {
    opacity: 1;
}

.terminal-title {
    font-family: var(--font-mono);
    font-size: 0.8125rem;
    color: var(--text-tertiary);
    font-weight: 500;
}

.terminal-body {
    padding: var(--space-xl);
    min-height: 200px;
    background: var(--terminal-bg);
}

.terminal-window.small .terminal-body {
    padding: var(--space-lg);
    min-height: 100px;
}

.output {
    font-family: var(--font-mono);
    font-size: 0.9375rem;
    line-height: 1.5;
    color: var(--terminal-text);
    white-space: pre;
    overflow-x: auto;
}

/* === CODE BLOCKS === */
.code-block {
    background: var(--bg-code);
    border-radius: 8px;
    padding: var(--space-xl);
    margin-top: var(--space-xl);
    overflow-x: auto;
    border: 1px solid var(--border-subtle);
    position: relative;
}

.code-block::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 1px;
    background: linear-gradient(90deg,
        transparent,
        var(--accent-primary),
        transparent);
    opacity: 0;
    transition: opacity var(--duration-normal) var(--ease-smooth);
}

.code-block:hover::before {
    opacity: 0.3;
}

.code-block code {
    font-family: var(--font-mono);
    font-size: 0.9375rem;
    line-height: 1.7;
    color: var(--text-primary);
    display: block;
    white-space: pre;
    background: none;
    padding: 0;
}

/* === LISTS === */
ul.feature-list,
ul.resource-list {
    list-style: none;
    margin-top: var(--space-xl);
}

ul.feature-list li,
ul.resource-list li {
    margin-bottom: var(--space-lg);
    padding-left: var(--space-xl);
    position: relative;
    transition: transform var(--duration-fast) var(--ease-smooth);
}

ul.feature-list li:hover {
    transform: translateX(4px);
}

ul.feature-list li::before {
    content: '▸';
    position: absolute;
    left: 0;
    color: var(--accent-primary);
    font-weight: bold;
    transition: transform var(--duration-fast) var(--ease-smooth);
}

ul.feature-list li:hover::before {
    transform: translateX(4px);
}

ul.resource-list li {
    padding-left: 0;
}

ul.resource-list li strong {
    display: block;
    margin-bottom: var(--space-xs);
    color: var(--accent-primary);
}

ul.resource-list li p {
    color: var(--text-secondary);
    margin-bottom: 0;
}

/* === TECHNIQUES === */
.technique-list {
    display: flex;
    flex-direction: column;
    gap: var(--space-4xl);
}

.technique {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--space-2xl);
    align-items: start;
    padding: var(--space-3xl);
    background: var(--bg-secondary);
    border-radius: 16px;
    border: 1px solid var(--border-subtle);
    transition: all var(--duration-normal) var(--ease-smooth);
}

.technique:hover {
    border-color: var(--accent-muted);
    box-shadow: 0 8px 32px rgba(0, 255, 65, 0.08);
}

.technique-text ul {
    list-style: none;
    margin-top: var(--space-lg);
}

.technique-text ul li {
    padding-left: var(--space-lg);
    margin-bottom: var(--space-sm);
    position: relative;
    color: var(--text-secondary);
}

.technique-text ul li::before {
    content: '›';
    position: absolute;
    left: 0;
    color: var(--accent-primary);
}

.demo-window {
    background: var(--terminal-bg);
    border-radius: 8px;
    padding: var(--space-lg);
    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.4);
    border: 1px solid var(--border-default);
}

.demo-window .output {
    min-height: 120px;
}

/* === COMPARISON === */
.technique-comparison {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--space-lg);
    margin-top: var(--space-xl);
}

.comparison-item {
    background: var(--bg-secondary);
    padding: var(--space-xl);
    border-radius: 12px;
    border: 1px solid var(--border-subtle);
    transition: all var(--duration-normal) var(--ease-smooth);
}

.comparison-item:hover {
    border-color: var(--accent-muted);
    transform: translateY(-2px);
}

.comparison-item h4 {
    margin-top: 0;
}

.pros-cons {
    margin-top: var(--space-lg);
    font-size: 0.9375rem;
}

.pros,
.cons {
    margin-bottom: var(--space-sm);
}

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

.cons strong {
    color: #ff7b72;
}

/* === PATTERNS === */
.pattern-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--space-xl);
}

.pattern-item {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity var(--duration-slow) var(--ease-smooth),
                transform var(--duration-slow) var(--ease-smooth);
}

.pattern-item.visible {
    opacity: 1;
    transform: translateY(0);
}

.pattern-item h4 {
    margin-bottom: var(--space-md);
    color: var(--text-bright);
}

/* === CHARACTER SETS === */
.charset-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--space-2xl);
    margin-top: var(--space-2xl);
}

.charset-item {
    background: var(--bg-secondary);
    padding: var(--space-2xl);
    border-radius: 12px;
    border: 1px solid var(--border-subtle);
    transition: all var(--duration-normal) var(--ease-smooth);
    opacity: 0;
    transform: translateY(20px);
}

.charset-item.visible {
    opacity: 1;
    transform: translateY(0);
}

.charset-item:hover {
    border-color: var(--accent-muted);
}

.charset-item h4 {
    margin-top: 0;
    color: var(--accent-primary);
}

.char-display {
    font-family: var(--font-mono);
    font-size: 1.75rem;
    letter-spacing: 0.75rem;
    margin: var(--space-xl) 0;
    color: var(--accent-secondary);
    background: var(--bg-code);
    padding: var(--space-xl);
    border-radius: 8px;
    text-align: center;
    overflow-x: auto;
}

.charset-item p {
    font-size: 0.9375rem;
    color: var(--text-secondary);
    line-height: 1.7;
}

/* === TOOLS === */
.tool-list {
    display: flex;
    flex-direction: column;
    gap: var(--space-2xl);
}

.tool-item {
    background: var(--bg-secondary);
    padding: var(--space-2xl);
    border-radius: 12px;
    border: 1px solid var(--border-subtle);
    transition: all var(--duration-normal) var(--ease-smooth);
}

.tool-item:hover {
    border-color: var(--accent-muted);
    transform: translateX(4px);
}

.tool-item h4 {
    margin-top: 0;
    color: var(--accent-primary);
}

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

/* === EXAMPLES === */
.examples-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--space-2xl);
}

.example-card {
    background: var(--bg-secondary);
    border: 1px solid var(--border-subtle);
    border-radius: 12px;
    padding: var(--space-2xl);
    transition: all var(--duration-normal) var(--ease-smooth);
    opacity: 0;
    transform: translateY(20px);
}

.example-card.visible {
    opacity: 1;
    transform: translateY(0);
}

.example-card:hover {
    border-color: var(--accent-muted);
    box-shadow: 0 8px 32px rgba(0, 255, 65, 0.12);
    transform: translateY(-4px);
}

.example-card h4 {
    margin-top: 0;
    color: var(--text-bright);
}

.example-meta {
    font-size: 0.875rem;
    color: var(--text-tertiary);
    margin-bottom: var(--space-md);
    font-family: var(--font-mono);
}

.example-card p {
    color: var(--text-secondary);
    line-height: 1.7;
}

.example-code {
    display: block;
    font-family: var(--font-mono);
    font-size: 0.875rem;
    color: var(--accent-secondary);
    background: var(--bg-code);
    padding: var(--space-sm) var(--space-lg);
    border-radius: 6px;
    margin-top: var(--space-lg);
    border: 1px solid var(--border-subtle);
}

/* === FOOTER === */
.footer {
    padding: var(--space-4xl) 0 var(--space-2xl);
    text-align: center;
    border-top: 1px solid var(--border-subtle);
    background: var(--bg-secondary);
}

.footer p {
    color: var(--text-secondary);
    margin-bottom: var(--space-sm);
}

.footer-note {
    font-size: 0.875rem;
    color: var(--text-tertiary);
}

/* === SCROLLBAR === */
::-webkit-scrollbar {
    width: 10px;
    height: 10px;
}

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

::-webkit-scrollbar-thumb {
    background: var(--border-subtle);
    border-radius: 5px;
    transition: background var(--duration-fast);
}

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

/* === RESPONSIVE === */
@media (min-width: 640px) {
    .pattern-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .charset-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .technique-comparison {
        grid-template-columns: repeat(3, 1fr);
    }
}

@media (min-width: 768px) {
    .examples-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (min-width: 1024px) {
    .technique {
        grid-template-columns: 1.2fr 1fr;
        gap: var(--space-4xl);
    }

    .pattern-grid {
        grid-template-columns: repeat(3, 1fr);
    }
}

/* === MOBILE === */
@media (max-width: 1023px) {
    :root {
        --space-4xl: 4rem;
        --space-5xl: 5rem;
    }

    .menu-toggle {
        display: flex;
    }

    .nav {
        transform: translateX(-100%);
        box-shadow: 4px 0 24px rgba(0, 0, 0, 0.5);
    }

    .nav.open {
        transform: translateX(0);
    }

    .main {
        margin-left: 0;
    }

    .section {
        padding: var(--space-4xl) 0;
    }

    .hero {
        min-height: 100svh;
        padding: var(--space-3xl) 0;
    }

    .container,
    .container-narrow {
        padding: 0 var(--space-lg);
    }

    .terminal-body {
        padding: var(--space-lg);
        min-height: 180px;
    }

    .output {
        font-size: 0.8125rem;
    }

    .code-block {
        padding: var(--space-lg);
    }

    .code-block code {
        font-size: 0.8125rem;
    }

    .technique,
    .tool-item,
    .charset-item {
        padding: var(--space-xl);
    }

    .char-display {
        font-size: 1.25rem;
        letter-spacing: 0.5rem;
        padding: var(--space-lg);
    }

    .scroll-indicator {
        bottom: var(--space-2xl);
    }
}

@media (max-width: 640px) {
    :root {
        --space-3xl: 3rem;
        --space-4xl: 3.5rem;
        --space-5xl: 4rem;
    }

    .container,
    .container-narrow {
        padding: 0 var(--space-md);
    }

    .technique,
    .charset-item,
    .tool-item,
    .example-card {
        padding: var(--space-lg);
    }

    .char-display {
        font-size: 1rem;
        letter-spacing: 0.25rem;
    }
}

/* === ACCESSIBILITY === */
@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
        scroll-behavior: auto !important;
    }

    .hero::before {
        animation: none;
    }

    .scroll-indicator::before {
        animation: none;
    }
}

/* Focus styles */
a:focus-visible,
button:focus-visible,
.menu-toggle:focus-visible {
    outline: 2px solid var(--accent-primary);
    outline-offset: 4px;
}

/* Selection */
::selection {
    background: var(--accent-muted);
    color: var(--text-bright);
}