/* ═══════════════════════════════════════════════════════════
   BuildBrief — GitHub Pages — Aurora Theme
   ═══════════════════════════════════════════════════════════ */

:root {
    --color-bg: #0F0F12;
    --color-bg-secondary: #0a0a0c;
    --color-surface: #18181B;
    --color-surface-hover: #27272A;
    --color-text: #FAFAFA;
    --color-text-muted: #A1A1AA;
    --color-border: #27272A;
    --color-primary: #8B5CF6;
    --color-primary-hover: #7C3AED;
    --color-primary-glow: rgba(139, 92, 246, 0.15);
    --color-secondary: #F59E0B;
    --color-accent: #06B6D4;
    --gradient-glow-1: rgba(139, 92, 246, 0.12);
    --gradient-glow-2: rgba(245, 158, 11, 0.08);
    --glass-bg: rgba(24, 24, 27, 0.8);
    --glass-border: rgba(39, 39, 42, 0.5);
    --shadow-card: 0 8px 32px rgba(0, 0, 0, 0.3);
}

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

html {
    scroll-behavior: smooth;
    font-size: 100%;
}

body {
    background-color: var(--color-bg);
    color: var(--color-text);
    font-family: 'Inter', system-ui, -apple-system, sans-serif;
    -webkit-font-smoothing: antialiased;
    overflow-x: hidden;
    background-image:
        radial-gradient(ellipse 80% 50% at 50% -20%, var(--gradient-glow-1), transparent),
        radial-gradient(ellipse 60% 40% at 80% 100%, var(--gradient-glow-2), transparent),
        linear-gradient(to bottom, #0F0F12, #0a0a0c);
    min-height: 100vh;
    line-height: 1.6;
}

.grain-overlay {
    position: fixed;
    inset: 0;
    background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.7' numOctaves='3' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
    opacity: 0.03;
    pointer-events: none;
    z-index: 9999;
}

::selection {
    background: rgba(139, 92, 246, 0.3);
    color: var(--color-text);
}

a {
    color: inherit;
    text-decoration: none;
}

/* ═══════════════════════════════════════════════════════════
   Typography
   ═══════════════════════════════════════════════════════════ */

.gradient-text {
    background: linear-gradient(135deg, #8B5CF6, #F59E0B, #06B6D4);
    background-size: 200% 200%;
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    animation: shimmer 4s ease infinite;
}

@keyframes shimmer {
    0%, 100% { background-position: 0% 50%; }
    50% { background-position: 100% 50%; }
}

/* ═══════════════════════════════════════════════════════════
   Navigation
   ═══════════════════════════════════════════════════════════ */

.nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 100;
    background: rgba(15, 15, 18, 0.8);
    backdrop-filter: blur(24px);
    border-bottom: 1px solid var(--glass-border);
}

.nav-inner {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
    height: 64px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-weight: 700;
    font-size: 1.25rem;
}

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

.logo-text {
    font-family: 'Clash Display', 'Inter', sans-serif;
}

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

.nav-links a {
    color: var(--color-text-muted);
    font-size: 0.875rem;
    font-weight: 500;
    transition: color 0.2s;
}

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

.nav-github {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 1rem;
    border-radius: 0.5rem;
    border: 1px solid var(--color-border);
    transition: all 0.2s;
}

.nav-github:hover {
    border-color: var(--color-primary-glow);
    background: var(--color-surface-hover);
}

/* ═══════════════════════════════════════════════════════════
   Buttons
   ═══════════════════════════════════════════════════════════ */

.btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1.5rem;
    border-radius: 0.75rem;
    font-weight: 600;
    font-size: 0.9375rem;
    transition: all 0.2s ease;
    cursor: pointer;
    border: none;
    font-family: inherit;
}

.btn-primary {
    background: var(--color-primary);
    color: white;
    box-shadow: 0 4px 14px rgba(139, 92, 246, 0.3);
}

.btn-primary:hover {
    background: var(--color-primary-hover);
    box-shadow: 0 6px 20px rgba(139, 92, 246, 0.4);
    transform: translateY(-1px);
}

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

.btn-secondary:hover {
    background: var(--color-surface-hover);
    border-color: var(--color-primary-glow);
}

.btn-lg {
    padding: 1rem 2rem;
    font-size: 1.0625rem;
}

.btn:active {
    transform: scale(0.98);
}

/* ═══════════════════════════════════════════════════════════
   Hero
   ═══════════════════════════════════════════════════════════ */

.hero {
    position: relative;
    padding: 10rem 2rem 6rem;
    text-align: center;
}

.hero-glow {
    position: absolute;
    border-radius: 50%;
    pointer-events: none;
}

.hero-glow-1 {
    width: 800px;
    height: 800px;
    top: -300px;
    left: 50%;
    transform: translateX(-50%);
    background: radial-gradient(circle, rgba(139, 92, 246, 0.15) 0%, transparent 70%);
}

.hero-glow-2 {
    width: 600px;
    height: 600px;
    bottom: -150px;
    right: 5%;
    background: radial-gradient(circle, rgba(245, 158, 11, 0.12) 0%, transparent 70%);
}

.hero-content {
    position: relative;
    max-width: 800px;
    margin: 0 auto;
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 1rem;
    border-radius: 2rem;
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    font-size: 0.8125rem;
    font-weight: 500;
    color: var(--color-text-muted);
    margin-bottom: 2rem;
    animation: fadeSlideUp 0.6s ease-out;
}

.badge-dot {
    width: 6px;
    height: 6px;
    border-radius: 50%;
    background: #10B981;
    animation: pulse-dot 2s infinite;
}

@keyframes pulse-dot {
    0%, 100% { opacity: 1; transform: scale(1); }
    50% { opacity: 0.5; transform: scale(1.5); }
}

.hero-title {
    font-family: 'Clash Display', 'Inter', sans-serif;
    font-size: clamp(2.5rem, 6vw, 4.5rem);
    font-weight: 700;
    line-height: 1.1;
    margin-bottom: 1.5rem;
    animation: fadeSlideUp 0.6s ease-out 0.1s both;
}

.hero-subtitle {
    font-size: 1.125rem;
    color: var(--color-text-muted);
    max-width: 600px;
    margin: 0 auto 2.5rem;
    line-height: 1.7;
    animation: fadeSlideUp 0.6s ease-out 0.2s both;
}

.hero-actions {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
    margin-bottom: 3rem;
    animation: fadeSlideUp 0.6s ease-out 0.3s both;
}

.tech-badges {
    display: flex;
    gap: 0.5rem;
    justify-content: center;
    flex-wrap: wrap;
    animation: fadeSlideUp 0.6s ease-out 0.4s both;
}

.tech-badge {
    padding: 0.375rem 0.75rem;
    border-radius: 0.5rem;
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    font-size: 0.75rem;
    font-weight: 500;
    color: var(--color-text-muted);
}

@keyframes fadeSlideUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* ═══════════════════════════════════════════════════════════
   Sections
   ═══════════════════════════════════════════════════════════ */

.section-inner {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
}

.section-header {
    text-align: center;
    margin-bottom: 4rem;
}

.section-title {
    font-family: 'Clash Display', 'Inter', sans-serif;
    font-size: clamp(2rem, 4vw, 3rem);
    font-weight: 700;
    margin-bottom: 1rem;
}

.section-subtitle {
    font-size: 1.0625rem;
    color: var(--color-text-muted);
    max-width: 500px;
    margin: 0 auto;
}

/* ═══════════════════════════════════════════════════════════
   Features
   ═══════════════════════════════════════════════════════════ */

.features {
    padding: 6rem 0;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 1.5rem;
}

.feature-card {
    background: var(--glass-bg);
    backdrop-filter: blur(24px);
    border: 1px solid var(--glass-border);
    border-radius: 1rem;
    padding: 2rem;
    transition: all 0.3s ease;
    cursor: default;
}

.feature-card:hover {
    border-color: var(--color-primary-glow);
    transform: translateY(-4px);
    box-shadow:
        0 12px 40px rgba(0, 0, 0, 0.2),
        0 0 20px var(--color-primary-glow);
}

.feature-icon {
    font-size: 2rem;
    margin-bottom: 1rem;
    width: 56px;
    height: 56px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 0.75rem;
    background: rgba(139, 92, 246, 0.1);
}

.feature-card h3 {
    font-family: 'Clash Display', 'Inter', sans-serif;
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 0.75rem;
}

.feature-card p {
    color: var(--color-text-muted);
    font-size: 0.9375rem;
    line-height: 1.6;
}

/* ═══════════════════════════════════════════════════════════
   How It Works
   ═══════════════════════════════════════════════════════════ */

.how-it-works {
    padding: 6rem 0;
}

.steps {
    max-width: 700px;
    margin: 0 auto;
    position: relative;
}

.steps::before {
    content: '';
    position: absolute;
    left: 24px;
    top: 0;
    bottom: 0;
    width: 2px;
    background: linear-gradient(
        to bottom,
        var(--color-primary),
        var(--color-secondary),
        var(--color-accent)
    );
    opacity: 0.3;
}

.step {
    display: flex;
    gap: 1.5rem;
    padding: 1.5rem 0;
    position: relative;
}

.step-number {
    width: 48px;
    height: 48px;
    border-radius: 50%;
    background: var(--color-surface);
    border: 2px solid var(--color-primary);
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 1rem;
    color: var(--color-primary);
    flex-shrink: 0;
    position: relative;
    z-index: 1;
    transition: all 0.3s ease;
}

.step:hover .step-number {
    background: var(--color-primary);
    color: white;
    box-shadow: 0 0 20px rgba(139, 92, 246, 0.4);
}

.step-content {
    padding-top: 0.5rem;
}

.step-content h3 {
    font-family: 'Clash Display', 'Inter', sans-serif;
    font-size: 1.125rem;
    font-weight: 600;
    margin-bottom: 0.375rem;
}

.step-content p {
    color: var(--color-text-muted);
    font-size: 0.9375rem;
}

/* ═══════════════════════════════════════════════════════════
   CTA
   ═══════════════════════════════════════════════════════════ */

.cta {
    padding: 6rem 0;
}

.cta-card {
    position: relative;
    background: var(--glass-bg);
    backdrop-filter: blur(24px);
    border: 1px solid var(--glass-border);
    border-radius: 1.5rem;
    padding: 4rem 2rem;
    text-align: center;
    overflow: hidden;
}

.cta-glow {
    position: absolute;
    width: 600px;
    height: 600px;
    top: -250px;
    left: 50%;
    transform: translateX(-50%);
    background: radial-gradient(circle, rgba(139, 92, 246, 0.15) 0%, transparent 70%);
    border-radius: 50%;
    pointer-events: none;
}

.cta-card h2 {
    font-family: 'Clash Display', 'Inter', sans-serif;
    font-size: clamp(1.75rem, 3vw, 2.5rem);
    font-weight: 700;
    margin-bottom: 1rem;
    position: relative;
}

.cta-card p {
    color: var(--color-text-muted);
    font-size: 1.0625rem;
    margin-bottom: 2rem;
    position: relative;
}

.cta-actions {
    margin-bottom: 2rem;
    position: relative;
}

.cta-code {
    display: inline-flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.75rem 1rem;
    border-radius: 0.75rem;
    background: var(--color-bg);
    border: 1px solid var(--color-border);
    position: relative;
}

.cta-code code {
    font-family: 'JetBrains Mono', 'Fira Code', monospace;
    font-size: 0.8125rem;
    color: var(--color-text-muted);
}

.copy-btn {
    padding: 0.375rem 0.75rem;
    border-radius: 0.375rem;
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    color: var(--color-text-muted);
    font-size: 0.75rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s;
    font-family: inherit;
}

.copy-btn:hover {
    background: var(--color-surface-hover);
    color: var(--color-text);
}

/* ═══════════════════════════════════════════════════════════
   Footer
   ═══════════════════════════════════════════════════════════ */

.footer {
    padding: 3rem 0;
    border-top: 1px solid var(--glass-border);
}

.footer-inner {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1rem;
    text-align: center;
}

.footer-brand {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-weight: 700;
}

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

.footer-links {
    display: flex;
    gap: 1.5rem;
}

.footer-links a {
    color: var(--color-text-muted);
    font-size: 0.8125rem;
    transition: color 0.2s;
}

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

/* ═══════════════════════════════════════════════════════════
   Responsive
   ═══════════════════════════════════════════════════════════ */

@media (max-width: 768px) {
    .nav-links a:not(.nav-github) {
        display: none;
    }

    .hero {
        padding: 8rem 1.5rem 4rem;
    }

    .hero-title {
        font-size: 2.25rem;
    }

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

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

    .cta-card {
        padding: 3rem 1.5rem;
    }

    .cta-code {
        flex-direction: column;
        gap: 0.5rem;
    }

    .cta-code code {
        font-size: 0.6875rem;
    }

    .steps::before {
        left: 20px;
    }

    .step-number {
        width: 40px;
        height: 40px;
        font-size: 0.875rem;
    }
}

/* ═══════════════════════════════════════════════════════════
   Scroll animations
   ═══════════════════════════════════════════════════════════ */

.feature-card,
.step {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.5s ease, transform 0.5s ease;
}

.feature-card.visible,
.step.visible {
    opacity: 1;
    transform: translateY(0);
}