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

:root {
    --bg: #0d0f14;
    --surface: #131720;
    --border: #1e2535;
    --accent: #3b82f6;
    --accent-dim: #1e3a5f;
    --text: #e2e8f0;
    --text-muted: #8892a4;
    --text-dim: #4e5a6e;
    --mono: 'JetBrains Mono', monospace;
    --sans: 'Inter', system-ui, sans-serif;
    --radius: 6px;
    --max-w: 860px;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--sans);
    background: var(--bg);
    color: var(--text);
    font-size: 15px;
    line-height: 1.7;
    -webkit-font-smoothing: antialiased;
}

/* ── Layout helpers ── */
.container {
    max-width: var(--max-w);
    margin: 0 auto;
    padding: 0 24px;
}

section {
    padding: 72px 0;
}

section+section {
    border-top: 1px solid var(--border);
}

/* ── Header / Nav ── */
header {
    position: sticky;
    top: 0;
    z-index: 100;
    background: rgba(13, 15, 20, 0.92);
    backdrop-filter: blur(8px);
    border-bottom: 1px solid var(--border);
}

.nav {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 56px;
}

.nav-brand {
    font-family: var(--mono);
    font-size: 14px;
    font-weight: 500;
    color: var(--text);
    letter-spacing: 0.04em;
    text-decoration: none;
}

.nav-brand span {
    color: var(--accent);
}

.nav-links {
    display: flex;
    gap: 28px;
    list-style: none;
}

.nav-links a {
    font-size: 13px;
    color: var(--text-muted);
    text-decoration: none;
    letter-spacing: 0.02em;
    transition: color 0.2s;
}

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

/* ── Hero ── */
#hero {
    padding: 100px 0 80px;
    border-top: none;
}

.hero-tag {
    display: inline-block;
    font-family: var(--mono);
    font-size: 11px;
    font-weight: 500;
    letter-spacing: 0.12em;
    text-transform: uppercase;
    color: var(--accent);
    background: var(--accent-dim);
    border: 1px solid rgba(59, 130, 246, 0.25);
    border-radius: 3px;
    padding: 3px 10px;
    margin-bottom: 28px;
}

h1 {
    font-size: clamp(26px, 4vw, 38px);
    font-weight: 600;
    line-height: 1.25;
    letter-spacing: -0.02em;
    color: var(--text);
    max-width: 640px;
    margin-bottom: 20px;
}

.hero-subtitle {
    font-size: 16px;
    color: var(--text-muted);
    max-width: 520px;
    line-height: 1.65;
    margin-bottom: 40px;
}

.hero-meta {
    display: flex;
    gap: 32px;
    align-items: center;
    flex-wrap: wrap;
}

.hero-meta-item {
    display: flex;
    align-items: center;
    gap: 8px;
    font-family: var(--mono);
    font-size: 12px;
    color: var(--text-dim);
}

.hero-meta-item .dot {
    width: 6px;
    height: 6px;
    border-radius: 50%;
    background: var(--accent);
    flex-shrink: 0;
}

/* ── Section headings ── */
h2 {
    font-size: 20px;
    font-weight: 600;
    letter-spacing: -0.01em;
    color: var(--text);
    margin-bottom: 6px;
}

.section-label {
    font-family: var(--mono);
    font-size: 11px;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    color: var(--text-dim);
    margin-bottom: 14px;
}

.section-intro {
    color: var(--text-muted);
    max-width: 600px;
    margin-bottom: 40px;
}

/* ── Cards ── */
.card-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
    gap: 16px;
}

.card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 24px;
    transition: border-color 0.2s;
}

.card:hover {
    border-color: var(--accent-dim);
}

.card-icon {
    font-size: 20px;
    margin-bottom: 16px;
    display: block;
    line-height: 1;
}

.card h3 {
    font-size: 14px;
    font-weight: 600;
    color: var(--text);
    margin-bottom: 8px;
}

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

/* ── Info rows ── */
.info-list {
    display: flex;
    flex-direction: column;
    gap: 0;
}

.info-row {
    display: grid;
    grid-template-columns: 200px 1fr;
    gap: 16px;
    padding: 16px 0;
    border-bottom: 1px solid var(--border);
    align-items: start;
}

.info-row:first-child {
    border-top: 1px solid var(--border);
}

.info-key {
    font-family: var(--mono);
    font-size: 12px;
    color: var(--text-dim);
    padding-top: 2px;
}

.info-val {
    font-size: 13.5px;
    color: var(--text-muted);
    line-height: 1.65;
}

.info-val strong {
    color: var(--text);
    font-weight: 500;
}

/* ── Code block ── */
.code-block {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 20px 24px;
    font-family: var(--mono);
    font-size: 12.5px;
    color: var(--text-muted);
    line-height: 1.8;
    overflow-x: auto;
    margin-top: 24px;
}

.code-block .comment {
    color: var(--text-dim);
}

.code-block .key {
    color: #7dd3fc;
}

.code-block .val {
    color: #86efac;
}

/* ── Tag list ── */
.tag-list {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin-top: 20px;
}

.tag {
    font-family: var(--mono);
    font-size: 11px;
    font-weight: 500;
    color: var(--text-muted);
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 3px;
    padding: 4px 10px;
    letter-spacing: 0.04em;
}

/* ── Two columns ── */
.two-col {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 40px;
}

/* ── Footer ── */
footer {
    border-top: 1px solid var(--border);
    padding: 32px 0;
}

.footer-inner {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 12px;
}

.footer-brand {
    font-family: var(--mono);
    font-size: 12px;
    color: var(--text-dim);
}

.footer-brand span {
    color: var(--accent);
}

.footer-note {
    font-size: 12px;
    color: var(--text-dim);
}

/* ── Responsive ── */
@media (max-width: 640px) {
    .two-col {
        grid-template-columns: 1fr;
        gap: 28px;
    }

    .info-row {
        grid-template-columns: 1fr;
        gap: 4px;
    }

    .nav-links {
        display: none;
    }
}