:root {
    --bg: #f7f9fb;
    --surface: #ffffff;
    --text: #1d1d1f;
    --muted: #6b7280;
    --primary: #2b6cb0;
    --primary-hover: #1e4e8c;
    --border: #e5e7eb;
    --code-bg: #f1f5f9;
    --max-width: 720px;
}

@media (prefers-color-scheme: dark) {
    :root {
        --bg: #0f1216;
        --surface: #1a1f26;
        --text: #e6e9ef;
        --muted: #9aa3b2;
        --primary: #6aa9e9;
        --primary-hover: #93c0f2;
        --border: #2a313b;
        --code-bg: #232a33;
    }
}

* {
    box-sizing: border-box;
}

html {
    -webkit-text-size-adjust: 100%;
}

body {
    margin: 0;
    padding: 24px 20px 80px;
    font-family: -apple-system, BlinkMacSystemFont, "SF Pro Text", "Segoe UI", Roboto, sans-serif;
    font-size: 17px;
    line-height: 1.55;
    color: var(--text);
    background: var(--bg);
}

main {
    max-width: var(--max-width);
    margin: 0 auto;
    background: var(--surface);
    padding: 32px 28px;
    border-radius: 14px;
    border: 1px solid var(--border);
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.03);
}

header {
    max-width: var(--max-width);
    margin: 0 auto 18px;
    padding: 4px 4px;
    display: flex;
    align-items: center;
    gap: 10px;
    color: var(--muted);
    font-size: 14px;
}

header a {
    color: var(--muted);
    text-decoration: none;
}

header a:hover {
    color: var(--primary);
}

h1 {
    margin: 0 0 8px;
    font-size: 28px;
    line-height: 1.2;
    font-weight: 700;
    letter-spacing: -0.01em;
}

h2 {
    margin: 32px 0 10px;
    font-size: 20px;
    line-height: 1.3;
    font-weight: 600;
    letter-spacing: -0.005em;
}

h3 {
    margin: 22px 0 6px;
    font-size: 17px;
    font-weight: 600;
}

p {
    margin: 0 0 14px;
}

ul, ol {
    margin: 0 0 14px;
    padding-left: 22px;
}

li {
    margin-bottom: 6px;
}

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

a:hover {
    color: var(--primary-hover);
    text-decoration: underline;
}

strong {
    font-weight: 600;
}

hr {
    border: none;
    border-top: 1px solid var(--border);
    margin: 28px 0;
}

.subtitle {
    color: var(--muted);
    font-size: 14px;
    margin-bottom: 24px;
}

footer {
    max-width: var(--max-width);
    margin: 24px auto 0;
    padding: 12px 4px;
    color: var(--muted);
    font-size: 14px;
    display: flex;
    gap: 18px;
    flex-wrap: wrap;
}

footer a {
    color: var(--muted);
}

footer a:hover {
    color: var(--primary);
}

@media (max-width: 480px) {
    body {
        padding: 16px 12px 60px;
    }

    main {
        padding: 24px 20px;
        border-radius: 10px;
    }

    h1 {
        font-size: 24px;
    }
}