body {
    margin: 0;
    height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-direction: column;
    font-family: sans-serif;
    background: #f8fafc;
    color: #0f172a;
    text-align: center;
}
h1 {
    font-size: 5rem;
    margin: 0;
}
p {
    margin: 0.5rem 0 1.5rem;
    color: #475569;
}
a.button {
    display: inline-block;
    padding: 0.75rem 1.25rem;
    border-radius: 8px;
    text-decoration: none;
    background: #0ea5e9;
    color: white;
    font-weight: bold;
}
a.button:hover {
    background: #0284c7;
}