:root {
    --text: #1d1d1f;
    --muted: #6e6e73;
    --link: #0066cc;
    --background: #ffffff;
    --rule: #d2d2d7;
}

@media (prefers-color-scheme: dark) {
    :root {
        --text: #f5f5f7;
        --muted: #a1a1a6;
        --link: #4da3ff;
        --background: #000000;
        --rule: #424245;
    }
}

body {
    max-width: 720px;
    margin: 0 auto;
    padding: 32px 16px 64px;
    font-family: -apple-system, BlinkMacSystemFont, "Helvetica Neue", Arial, sans-serif;
    font-size: 17px;
    line-height: 1.55;
    color: var(--text);
    background: var(--background);
}

h1 { font-size: 2rem; line-height: 1.2; }
h2 { margin-top: 2.2rem; font-size: 1.35rem; }
h3 { margin-top: 1.6rem; font-size: 1.1rem; }
a { color: var(--link); }
hr { border: 0; border-top: 1px solid var(--rule); margin: 2.5rem 0; }
em { color: var(--muted); }