body {
    margin: 0;
    font-family: Arial, sans-serif;
    background: #f4f4f4;
    color: #222;
}

header {
    background: #1f1f1f;
    color: white;
    padding: 24px;
    text-align: center;
}

header h1 {
    margin: 0;
    font-size: 2rem;
}

main {
    max-width: 700px;
    margin: 40px auto;
    padding: 20px;
}

.card {
    background: white;
    padding: 30px;
    border-radius: 12px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    text-align: center;
}

.button {
    display: block;
    width: 100%;
    box-sizing: border-box;
    margin: 15px 0;
    padding: 18px;
    border-radius: 8px;
    text-decoration: none;
    font-size: 1.1rem;
    font-weight: bold;
}

.primary {
    background: #b30000;
    color: white;
}

.secondary {
    background: #333;
    color: white;
}

footer {
    text-align: center;
    padding: 20px;
    color: #666;
    font-size: 0.9rem;
}

input:invalid,
select:invalid,
textarea:invalid {
    border-color: #b30000;
}

input:focus:invalid,
select:focus:invalid,
textarea:focus:invalid {
    outline: 2px solid #b30000;
    outline-offset: 1px;
}