/* ===================================
   Complete Landing Page
   Typographic Brutalism × Apple Refinement
   =================================== */

/* === CSS Variables === */
:root {
    /* Colors - Dark First */
    --bg-primary: #000000;
    --bg-secondary: #0a0a0a;
    --bg-tertiary: #141414;
    --text-primary: #ffffff;
    --text-secondary: #a0a0a0;
    --text-tertiary: #606060;
    --accent: #0071e3;
    --accent-hover: #0077ed;
    --border: rgba(255, 255, 255, 0.1);
    --shadow: rgba(0, 0, 0, 0.5);

    /* Typography */
    --font-system: -apple-system, BlinkMacSystemFont, "SF Pro Display", "SF Pro Text", "Helvetica Neue", sans-serif;
    --font-mono: ui-monospace, "SF Mono", Monaco, "Cascadia Code", "Roboto Mono", Menlo, Consolas, monospace;

    /* Spacing */
    --space-xs: 0.5rem;
    --space-sm: 1rem;
    --space-md: 2rem;
    --space-lg: 4rem;
    --space-xl: 6rem;
    --space-2xl: 8rem;

    /* Animation */
    --transition-fast: 0.15s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-base: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 0.5s cubic-bezier(0.4, 0, 0.2, 1);
    --spring: cubic-bezier(0.34, 1.56, 0.64, 1);
}

/* Light Mode */
@media (prefers-color-scheme: light) {
    :root {
        --bg-primary: #ffffff;
        --bg-secondary: #f5f5f7;
        --bg-tertiary: #e8e8ed;
        --text-primary: #1d1d1f;
        --text-secondary: #6e6e73;
        --text-tertiary: #86868b;
        --border: rgba(0, 0, 0, 0.1);
        --shadow: rgba(0, 0, 0, 0.1);
    }
}

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

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

body {
    font-family: var(--font-system);
    background: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.5;
    overflow-x: hidden;
}

/* === Typography === */
.mono {
    font-family: var(--font-mono);
    font-weight: 500;
    letter-spacing: -0.02em;
}

/* === Layout === */
main {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 var(--space-md);
}

section {
    padding: var(--space-2xl) 0;
    position: relative;
}

@media (max-width: 768px) {
    section {
        padding: var(--space-xl) 0;
    }
}

/* === Hero Section === */
.hero {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    text-align: center;
    padding: var(--space-2xl) 0;
    position: relative;
}

.hero-content {
    z-index: 2;
    animation: fadeInUp 0.8s var(--spring) backwards;
}

.hero-label {
    display: inline-flex;
    align-items: center;
    gap: var(--space-xs);
    color: var(--text-secondary);
    font-size: 0.875rem;
    margin-bottom: var(--space-md);
    padding: var(--space-xs) var(--space-sm);
    border: 1px solid var(--border);
    border-radius: 100px;
    background: var(--bg-secondary);
}

.hero-label .separator {
    opacity: 0.3;
}

.hero-title {
    font-size: clamp(4rem, 15vw, 12rem);
    font-weight: 800;
    letter-spacing: -0.04em;
    line-height: 0.9;
    margin-bottom: var(--space-sm);
    background: linear-gradient(135deg, var(--text-primary) 0%, var(--text-secondary) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    animation: fadeInUp 0.8s var(--spring) 0.1s backwards;
}

.hero-tagline {
    font-size: clamp(1.25rem, 3vw, 2rem);
    font-weight: 500;
    color: var(--text-secondary);
    margin-bottom: var(--space-lg);
    animation: fadeInUp 0.8s var(--spring) 0.2s backwards;
}

.hero-actions {
    display: flex;
    gap: var(--space-sm);
    justify-content: center;
    flex-wrap: wrap;
    margin-bottom: var(--space-md);
    animation: fadeInUp 0.8s var(--spring) 0.3s backwards;
}

.hero-requirement {
    font-size: 0.875rem;
    color: var(--text-tertiary);
    animation: fadeInUp 0.8s var(--spring) 0.4s backwards;
}

.hero-visual {
    margin-top: var(--space-2xl);
    animation: fadeInUp 0.8s var(--spring) 0.5s backwards;
}

.hotkey-display {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    font-size: clamp(2rem, 5vw, 4rem);
    font-weight: 300;
}

.hotkey-display .key {
    width: 1.5em;
    height: 1.5em;
    display: flex;
    align-items: center;
    justify-content: center;
    border: 2px solid var(--border);
    border-radius: 0.25em;
    background: var(--bg-secondary);
    box-shadow: 0 4px 20px var(--shadow);
    transition: transform var(--transition-base) var(--spring);
}

.hotkey-display .key:hover {
    transform: translateY(-4px) scale(1.05);
}

.hotkey-display .plus {
    color: var(--text-tertiary);
    font-weight: 300;
}

/* === Section Header === */
.section-header {
    margin-bottom: var(--space-xl);
    display: flex;
    align-items: baseline;
    gap: var(--space-md);
}

.section-number {
    font-size: clamp(3rem, 8vw, 6rem);
    font-weight: 800;
    color: var(--text-tertiary);
    line-height: 1;
    opacity: 0.3;
}

.section-title {
    font-size: clamp(2rem, 5vw, 3.5rem);
    font-weight: 700;
    letter-spacing: -0.03em;
}

/* === Features === */
.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--space-lg);
}

.feature-card {
    padding: var(--space-lg);
    border: 1px solid var(--border);
    border-radius: 16px;
    background: var(--bg-secondary);
    transition: all var(--transition-base);
    animation: fadeInUp 0.6s var(--spring) backwards;
}

.feature-card:nth-child(1) { animation-delay: 0.1s; }
.feature-card:nth-child(2) { animation-delay: 0.2s; }
.feature-card:nth-child(3) { animation-delay: 0.3s; }

.feature-card:hover {
    transform: translateY(-8px);
    border-color: var(--accent);
    box-shadow: 0 20px 60px var(--shadow);
}

.feature-icon {
    font-size: 3rem;
    margin-bottom: var(--space-md);
    display: block;
}

.feature-title {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: var(--space-sm);
    letter-spacing: -0.02em;
}

.feature-description {
    color: var(--text-secondary);
    line-height: 1.6;
}

/* === Performance === */
.metrics {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--space-lg);
}

.metric {
    padding: var(--space-lg);
    border: 1px solid var(--border);
    border-radius: 20px;
    background: var(--bg-secondary);
    text-align: center;
    animation: fadeInUp 0.6s var(--spring) backwards;
}

.metric:nth-child(1) { animation-delay: 0.1s; }
.metric:nth-child(2) { animation-delay: 0.2s; }
.metric:nth-child(3) { animation-delay: 0.3s; }

.metric-value {
    font-size: clamp(3rem, 8vw, 5rem);
    font-weight: 800;
    letter-spacing: -0.04em;
    line-height: 1;
    margin-bottom: var(--space-md);
    color: var(--accent);
    display: flex;
    align-items: baseline;
    justify-content: center;
    gap: 0.2em;
}

.metric-value .number {
    font-family: var(--font-mono);
}

.metric-value .number-sm {
    font-size: 0.6em;
    font-weight: 600;
}

.metric-value .unit {
    font-size: 0.5em;
    font-weight: 300;
    color: var(--text-tertiary);
}

.metric-value .suffix {
    font-size: 0.4em;
    font-weight: 500;
    color: var(--text-secondary);
}

.metric-label {
    font-size: 1.125rem;
    color: var(--text-secondary);
    font-weight: 500;
}

/* === How It Works === */
.steps {
    display: grid;
    gap: var(--space-lg);
    max-width: 800px;
    margin: 0 auto;
}

.step {
    display: grid;
    grid-template-columns: auto 1fr;
    gap: var(--space-md);
    align-items: start;
    padding: var(--space-lg);
    border: 1px solid var(--border);
    border-radius: 16px;
    background: var(--bg-secondary);
    transition: all var(--transition-base);
    animation: fadeInUp 0.6s var(--spring) backwards;
}

.step:nth-child(1) { animation-delay: 0.1s; }
.step:nth-child(2) { animation-delay: 0.2s; }
.step:nth-child(3) { animation-delay: 0.3s; }
.step:nth-child(4) { animation-delay: 0.4s; }

.step:hover {
    border-color: var(--accent);
    transform: translateX(8px);
}

.step-number {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--text-tertiary);
    line-height: 1;
}

.step-title {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: var(--space-xs);
    letter-spacing: -0.02em;
}

.step-description {
    color: var(--text-secondary);
    line-height: 1.6;
}

/* === Download Section === */
.download-section {
    text-align: center;
    padding: var(--space-2xl) 0;
    background: var(--bg-secondary);
    border-radius: 32px;
    margin: var(--space-2xl) 0;
}

.download-content {
    max-width: 600px;
    margin: 0 auto;
    animation: fadeInUp 0.6s var(--spring) backwards;
}

.download-title {
    font-size: clamp(2.5rem, 6vw, 4rem);
    font-weight: 700;
    letter-spacing: -0.03em;
    margin-bottom: var(--space-sm);
}

.download-subtitle {
    font-size: 1.25rem;
    color: var(--text-secondary);
    margin-bottom: var(--space-lg);
}

.download-note {
    margin-top: var(--space-md);
    font-size: 0.875rem;
    color: var(--text-tertiary);
}

/* === Buttons === */
.btn,
.download-btn {
    display: inline-flex;
    align-items: center;
    gap: var(--space-xs);
    padding: 1rem 2rem;
    font-family: var(--font-system);
    font-size: 1rem;
    font-weight: 600;
    text-decoration: none;
    border-radius: 100px;
    border: none;
    cursor: pointer;
    transition: all var(--transition-base) var(--spring);
    position: relative;
    overflow: hidden;
}

.btn.primary,
.download-btn.primary {
    background: var(--accent);
    color: #ffffff;
    box-shadow: 0 4px 20px rgba(0, 113, 227, 0.3);
}

.btn.primary:hover,
.download-btn.primary:hover {
    background: var(--accent-hover);
    transform: translateY(-2px);
    box-shadow: 0 8px 30px rgba(0, 113, 227, 0.4);
}

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

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

.btn.secondary:hover {
    background: var(--bg-tertiary);
    border-color: var(--text-secondary);
    transform: translateY(-2px);
}

.download-btn.large {
    padding: 1.5rem 3rem;
    font-size: 1.125rem;
    gap: var(--space-md);
}

.btn-text {
    position: relative;
    z-index: 1;
}

.btn-icon {
    font-size: 1.25em;
    transition: transform var(--transition-base);
}

.btn:hover .btn-icon,
.download-btn:hover .btn-icon {
    transform: translateX(4px);
}

.version-text {
    font-size: 0.75em;
    opacity: 0.7;
}

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

.footer-content {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 var(--space-md);
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: var(--space-md);
}

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

.footer-logo {
    font-size: 1.25rem;
    font-weight: 700;
    letter-spacing: -0.02em;
}

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

.footer-links {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    font-size: 0.875rem;
}

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

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

.footer-links .separator {
    color: var(--text-tertiary);
    opacity: 0.5;
}

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

/* === Focus Styles (Accessibility) === */
:focus-visible {
    outline: 2px solid var(--accent);
    outline-offset: 4px;
    border-radius: 4px;
}

/* === Reduced Motion === */
@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;
    }
}

/* === Mobile Responsive === */
@media (max-width: 768px) {
    .hero-actions {
        flex-direction: column;
        width: 100%;
    }

    .btn,
    .download-btn {
        width: 100%;
        justify-content: center;
    }

    .section-header {
        flex-direction: column;
        gap: var(--space-sm);
    }

    .metrics {
        grid-template-columns: 1fr;
    }

    .footer-content {
        flex-direction: column;
        text-align: center;
    }

    .footer-links {
        flex-wrap: wrap;
        justify-content: center;
    }
}

@media (max-width: 480px) {
    :root {
        font-size: 14px;
    }

    .hotkey-display {
        gap: var(--space-xs);
    }
}