/* ============================================
   Pi Coding Agent — Styles
   Inspired by autoresearch.lol layout
   ============================================ */

:root {
    --bg: #0a0a0b;
    --bg-alt: #111113;
    --bg-card: #151517;
    --border: #1e1e22;
    --border-hover: #2a2a30;
    --text: #e4e4e7;
    --text-secondary: #a1a1aa;
    --text-muted: #6b6b76;
    --accent: #6366f1;
    --accent-hover: #818cf8;
    --accent-dim: rgba(99, 102, 241, 0.08);
    --accent-glow: rgba(99, 102, 241, 0.15);
    --code-bg: #0d0d10;
    --radius: 10px;
    --radius-sm: 6px;
    --transition: 0.2s ease;
}

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

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    background: var(--bg);
    color: var(--text);
    line-height: 1.6;
    font-size: 15px;
}

::selection {
    background: var(--accent);
    color: #fff;
}

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

code {
    font-family: 'JetBrains Mono', 'Fira Code', 'Cascadia Code', monospace;
    font-size: 0.9em;
}

img {
    max-width: 100%;
    height: auto;
}

/* ============================================
   Navigation
   ============================================ */

.nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 100;
    padding: 0 24px;
    transition: background var(--transition), border-color var(--transition);
}

.nav-scrolled {
    background: rgba(10, 10, 11, 0.85);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border);
}

.nav-inner {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 56px;
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-weight: 600;
    font-size: 18px;
    color: var(--text);
}

.nav-logo svg {
    color: var(--accent);
}

.nav-links {
    display: flex;
    gap: 24px;
}

.nav-links a {
    font-size: 14px;
    color: var(--text-secondary);
    transition: color var(--transition);
}

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

/* ============================================
   Hero
   ============================================ */

.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    padding: 120px 24px 80px;
    overflow: hidden;
}

.hero-bg {
    position: absolute;
    inset: 0;
    background:
        radial-gradient(ellipse 600px 400px at 50% 40%, var(--accent-glow), transparent 70%),
        radial-gradient(ellipse 400px 300px at 20% 60%, rgba(99, 102, 241, 0.05), transparent 60%),
        radial-gradient(ellipse 300px 300px at 80% 30%, rgba(168, 85, 247, 0.05), transparent 60%);
    pointer-events: none;
}

.hero-content {
    max-width: 720px;
    text-align: center;
    position: relative;
    z-index: 1;
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 6px 14px;
    border: 1px solid var(--border);
    border-radius: 100px;
    font-size: 13px;
    color: var(--text-secondary);
    margin-bottom: 32px;
    background: var(--bg-card);
}

.badge-dot {
    width: 6px;
    height: 6px;
    border-radius: 50%;
    background: #22c55e;
}

.hero-title {
    font-size: clamp(48px, 8vw, 80px);
    font-weight: 700;
    line-height: 1.05;
    letter-spacing: -0.03em;
    margin-bottom: 20px;
    background: linear-gradient(180deg, #fff 30%, var(--text-secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: clamp(17px, 2.5vw, 21px);
    color: var(--text-secondary);
    line-height: 1.5;
    margin-bottom: 40px;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.hero-actions {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 16px;
    margin-bottom: 48px;
}

.hero-install {
    margin-top: 16px;
}

.install-code {
    display: inline-flex;
    align-items: center;
    gap: 12px;
    padding: 12px 20px;
    background: var(--code-bg);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    font-size: 13px;
    color: var(--text-secondary);
}

.install-code code {
    color: var(--text);
}

.install-hint {
    margin-top: 16px;
    font-size: 13px;
    color: var(--text-muted);
    letter-spacing: 1px;
    text-transform: uppercase;
    animation: bounce 2s infinite;
}

@keyframes bounce {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(4px); }
}

/* ============================================
   Buttons
   ============================================ */

.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 12px 24px;
    border-radius: var(--radius);
    font-size: 15px;
    font-weight: 500;
    cursor: pointer;
    transition: all var(--transition);
    border: none;
    font-family: inherit;
    line-height: 1;
}

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

.btn-primary:hover {
    background: var(--accent-hover);
    transform: translateY(-1px);
}

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

.btn-secondary:hover {
    background: var(--bg-card);
    border-color: var(--border-hover);
}

.copy-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 32px;
    height: 32px;
    background: transparent;
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    color: var(--text-muted);
    cursor: pointer;
    transition: all var(--transition);
    flex-shrink: 0;
}

.copy-btn:hover {
    color: var(--text);
    border-color: var(--border-hover);
    background: var(--bg-card);
}

/* ============================================
   Sections
   ============================================ */

.section {
    padding: 100px 24px;
}

.section-alt {
    background: var(--bg-alt);
}

.section-inner {
    max-width: 900px;
    margin: 0 auto;
}

.section-label {
    display: inline-block;
    font-size: 12px;
    font-weight: 600;
    letter-spacing: 1.5px;
    text-transform: uppercase;
    color: var(--accent);
    margin-bottom: 12px;
}

.section-title {
    font-size: clamp(28px, 4vw, 40px);
    font-weight: 700;
    line-height: 1.15;
    letter-spacing: -0.02em;
    margin-bottom: 20px;
}

.section-desc {
    font-size: 16px;
    color: var(--text-secondary);
    line-height: 1.7;
    max-width: 680px;
    margin-bottom: 16px;
}

.section-desc:last-of-type {
    margin-bottom: 48px;
}

/* ============================================
   Feature Grid
   ============================================ */

.feature-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 20px;
}

.feature-card {
    padding: 28px;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    transition: all var(--transition);
}

.feature-card:hover {
    border-color: var(--border-hover);
    transform: translateY(-2px);
}

.feature-icon {
    width: 44px;
    height: 44px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--accent-dim);
    border-radius: var(--radius-sm);
    margin-bottom: 16px;
    color: var(--accent);
}

.feature-card h3 {
    font-size: 17px;
    font-weight: 600;
    margin-bottom: 10px;
}

.feature-card p {
    font-size: 14px;
    color: var(--text-secondary);
    line-height: 1.6;
}

.feature-card code {
    font-size: 0.85em;
    color: var(--accent);
    background: var(--accent-dim);
    padding: 2px 6px;
    border-radius: 3px;
}

/* ============================================
   Modes Grid
   ============================================ */

.modes-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 16px;
}

.mode-card {
    padding: 28px;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
}

.mode-number {
    font-size: 13px;
    font-weight: 600;
    color: var(--accent);
    margin-bottom: 12px;
}

.mode-card h3 {
    font-size: 17px;
    font-weight: 600;
    margin-bottom: 10px;
}

.mode-card p {
    font-size: 14px;
    color: var(--text-secondary);
    line-height: 1.6;
}

.mode-card code {
    font-size: 0.85em;
    color: var(--accent);
    background: var(--accent-dim);
    padding: 2px 6px;
    border-radius: 3px;
}

/* ============================================
   Context Grid
   ============================================ */

.context-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 16px;
}

.context-item {
    padding: 24px;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
}

.context-item h3 {
    font-size: 15px;
    font-weight: 600;
    margin-bottom: 8px;
    font-family: 'JetBrains Mono', monospace;
}

.context-item p {
    font-size: 13px;
    color: var(--text-secondary);
    line-height: 1.6;
}

.context-item code {
    color: var(--accent);
    background: var(--accent-dim);
    padding: 1px 5px;
    border-radius: 3px;
    font-size: 0.85em;
}

/* ============================================
   Primitive Grid
   ============================================ */

.primitive-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 16px;
}

.primitive-card {
    padding: 24px;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
}

.primitive-card h3 {
    font-size: 15px;
    font-weight: 600;
    margin-bottom: 8px;
}

.primitive-card p {
    font-size: 13px;
    color: var(--text-secondary);
    line-height: 1.6;
}

/* ============================================
   Install Tabs
   ============================================ */

.install-tabs {
    margin-top: 32px;
}

.tab-nav {
    display: flex;
    gap: 4px;
    margin-bottom: 4px;
    background: var(--bg-card);
    padding: 4px;
    border-radius: var(--radius);
    border: 1px solid var(--border);
    width: fit-content;
}

.tab-btn {
    padding: 8px 16px;
    background: transparent;
    border: none;
    color: var(--text-secondary);
    font-size: 13px;
    font-weight: 500;
    cursor: pointer;
    border-radius: var(--radius-sm);
    transition: all var(--transition);
    font-family: inherit;
}

.tab-btn.active {
    background: var(--bg);
    color: var(--text);
}

.tab-btn:hover:not(.active) {
    color: var(--text);
}

.tab-content {
    display: none;
    margin-top: 8px;
}

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

.code-block {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
    padding: 16px 20px;
    background: var(--code-bg);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    font-size: 13px;
}

.code-block code {
    color: var(--text);
    word-break: break-all;
}

/* ============================================
   Community Grid
   ============================================ */

.community-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
}

.community-card {
    padding: 28px;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    transition: all var(--transition);
}

.community-card:hover {
    border-color: var(--border-hover);
    transform: translateY(-2px);
}

.community-icon {
    width: 44px;
    height: 44px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--accent-dim);
    border-radius: var(--radius-sm);
    margin-bottom: 16px;
    color: var(--accent);
}

.community-card h3 {
    font-size: 17px;
    font-weight: 600;
    margin-bottom: 10px;
}

.community-card p {
    font-size: 14px;
    color: var(--text-secondary);
    line-height: 1.6;
}

/* ============================================
   Footer
   ============================================ */

.footer {
    border-top: 1px solid var(--border);
    padding: 32px 24px;
}

.footer-inner {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    align-items: center;
    justify-content: space-between;
    font-size: 13px;
    color: var(--text-muted);
}

/* ============================================
   Responsive
   ============================================ */

@media (max-width: 768px) {
    .nav-links {
        display: none;
    }

    .hero {
        padding: 100px 20px 60px;
    }

    .hero-actions {
        flex-direction: column;
    }

    .section {
        padding: 60px 20px;
    }

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

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

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

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

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

    .footer-inner {
        flex-direction: column;
        gap: 8px;
        text-align: center;
    }

    .tab-nav {
        flex-wrap: wrap;
    }
}

@media (min-width: 769px) and (max-width: 1024px) {
    .context-grid {
        grid-template-columns: repeat(2, 1fr);
    }

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