:root {
    --text: #222;
    --muted: #666;
    --link: #2563eb;
    --bg: #fff;
    --max-width: 880px;
}

* {
    box-sizing: border-box;
}

body {
    margin: 0;
    font-family: system-ui, "Hiragino Sans", Meiryo, sans-serif;
    color: var(--text);
    background: var(--bg);
    line-height: 1.8;
}

header,
main,
footer {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 1.2rem;
}

header h1 {
    margin: 0 0 0.5rem;
}

nav a {
    margin-right: 12px;
    text-decoration: none;
    color: var(--link);
}

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

footer {
    margin-top: 2rem;
    color: var(--muted);
    font-size: 0.9rem;
    border-top: 1px solid #eee;
    padding-top: 0.8rem;
}