* {
    box-sizing: border-box;
}

html, body {
    margin: 0;
    min-height: 100%;
}

body {
    font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
    background: #f5f5f5;
    color: #222;
}

main {
    max-width: 720px;
    margin: 12vh auto;
    padding: 40px;
    background: #fff;
    border: 1px solid #ddd;
    border-radius: 12px;
}

h1 {
    margin-top: 0;
    font-size: 28px;
}

p {
    color: #666;
}