body {
    font-family: system-ui, sans-serif;
    background: #fafafa;
    color: #222;
    max-width: 640px;
    margin: 40px auto;
    padding: 0 16px;
}

h1 { color: #1e3a8a; }

button {
    padding: 6px 14px;
    border: 1px solid #1e3a8a;
    border-radius: 4px;
    background: white;
    color: #1e3a8a;
    cursor: pointer;
}

button:hover { background: #1e3a8a; color: white; }