:root {
    --bg-color: #ffffff;
    --text-color: #1a1a1a;
    --accent-color: #007AFF;
    --secondary-text: #666666;
    --max-width: 680px;
    --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

body {
    background-color: var(--bg-color);
    color: var(--text-color);
    font-family: var(--font-family);
    line-height: 1.6;
    margin: 0;
    padding: 0;
    -webkit-font-smoothing: antialiased;
}

.container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 60px 20px;
}

h1 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 10px;
    letter-spacing: -0.03em;
}

h2 {
    font-size: 1.5rem;
    margin-top: 40px;
    margin-bottom: 15px;
    font-weight: 600;
}

h3 {
    font-size: 1.2rem;
    margin-top: 30px;
    font-weight: 600;
}

p, li {
    font-size: 1.05rem;
    color: #333;
    margin-bottom: 16px;
}

ul {
    padding-left: 20px;
}

a {
    color: var(--text-color);
    text-decoration: underline;
    text-decoration-color: #ccc;
    text-underline-offset: 4px;
    transition: color 0.2s;
}

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

.last-updated {
    font-size: 0.9rem;
    color: var(--secondary-text);
    margin-bottom: 40px;
    display: block;
}

.footer {
    margin-top: 80px;
    padding-top: 20px;
    border-top: 1px solid #eaeaea;
    text-align: center;
    font-size: 0.9rem;
    color: var(--secondary-text);
}

@media (prefers-color-scheme: dark) {
    :root {
        --bg-color: #121212;
        --text-color: #f5f5f7;
        --secondary-text: #a1a1a6;
    }
    p, li { color: #d1d1d6; }
    .footer { border-top-color: #333; }
    a { text-decoration-color: #555; }
}