:root {
    --bg: #ffffff;
    --fg: #1c1c1e;
    --muted: #6b6b70;
    --accent: #007aff;
    --border: #e5e5ea;
    --card: #f7f7f8;
}
@media (prefers-color-scheme: dark) {
    :root {
        --bg: #000000;
        --fg: #f2f2f7;
        --muted: #98989f;
        --accent: #0a84ff;
        --border: #2c2c2e;
        --card: #1c1c1e;
    }
}
* { box-sizing: border-box; }
html, body {
    margin: 0;
    padding: 0;
    background: var(--bg);
    color: var(--fg);
    font-family: -apple-system, BlinkMacSystemFont, "SF Pro Text", "Helvetica Neue", Arial, sans-serif;
    font-size: 17px;
    line-height: 1.5;
    -webkit-text-size-adjust: 100%;
}
.wrap {
    max-width: 720px;
    margin: 0 auto;
    padding: 32px 20px 80px;
}
header {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 32px;
    padding-bottom: 16px;
    border-bottom: 1px solid var(--border);
}
header .brand {
    font-size: 20px;
    font-weight: 600;
}
header nav {
    margin-left: auto;
    display: flex;
    gap: 18px;
    font-size: 15px;
}
header nav a {
    color: var(--muted);
    text-decoration: none;
}
header nav a:hover { color: var(--accent); }
h1 {
    font-size: 32px;
    font-weight: 700;
    margin: 0 0 8px;
    letter-spacing: -0.5px;
}
h2 {
    font-size: 22px;
    font-weight: 600;
    margin: 32px 0 12px;
    letter-spacing: -0.2px;
}
h3 {
    font-size: 18px;
    font-weight: 600;
    margin: 24px 0 8px;
}
p { margin: 0 0 14px; }
ul { padding-left: 22px; margin: 0 0 14px; }
li { margin-bottom: 6px; }
a { color: var(--accent); }
.lead {
    font-size: 19px;
    color: var(--muted);
    margin-bottom: 28px;
}
.meta {
    font-size: 14px;
    color: var(--muted);
    margin-top: 32px;
    padding-top: 16px;
    border-top: 1px solid var(--border);
}
.card {
    background: var(--card);
    border-radius: 12px;
    padding: 20px 22px;
    margin: 16px 0;
}
.lang-switch {
    margin: 24px 0 0;
    font-size: 14px;
    color: var(--muted);
}
.lang-switch a { margin-left: 10px; }
footer {
    margin-top: 60px;
    padding-top: 20px;
    border-top: 1px solid var(--border);
    font-size: 14px;
    color: var(--muted);
    text-align: center;
}
code {
    background: var(--card);
    padding: 2px 6px;
    border-radius: 4px;
    font-size: 14px;
}