:root {
    --bg: #ffffff;
    --fg: #1c1c1e;
    --muted: #6b6b70;
    --accent: #2563eb;
    --card: #f5f5f7;
    --border: #e5e5ea;
}

@media (prefers-color-scheme: dark) {
    :root {
        --bg: #1c1c1e;
        --fg: #f5f5f7;
        --muted: #98989d;
        --accent: #60a5fa;
        --card: #2c2c2e;
        --border: #3a3a3c;
    }
}

* { box-sizing: border-box; }

body {
    margin: 0;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    line-height: 1.6;
    color: var(--fg);
    background: var(--bg);
    font-size: 16px;
}

.container {
    max-width: 760px;
    margin: 0 auto;
    padding: 32px 24px 80px;
}

header {
    border-bottom: 1px solid var(--border);
    padding-bottom: 16px;
    margin-bottom: 32px;
}

nav {
    display: flex;
    flex-wrap: wrap;
    gap: 16px;
    margin-top: 12px;
    font-size: 14px;
}

nav a {
    color: var(--accent);
    text-decoration: none;
}

nav a:hover { text-decoration: underline; }

h1 {
    font-size: 30px;
    margin: 0 0 8px;
    letter-spacing: -0.02em;
}

h2 {
    font-size: 22px;
    margin: 32px 0 8px;
    letter-spacing: -0.01em;
}

h3 {
    font-size: 17px;
    margin: 20px 0 4px;
}

p, li { margin: 8px 0; }

ul { padding-left: 22px; }

.subtitle {
    color: var(--muted);
    font-size: 14px;
    margin: 0;
}

.card {
    background: var(--card);
    border: 1px solid var(--border);
    border-radius: 14px;
    padding: 16px 20px;
    margin: 20px 0;
}

a { color: var(--accent); }

code {
    background: var(--card);
    padding: 2px 6px;
    border-radius: 6px;
    font-size: 14px;
}

footer {
    margin-top: 48px;
    padding-top: 16px;
    border-top: 1px solid var(--border);
    color: var(--muted);
    font-size: 13px;
}