header {
    background-color: #f0f0f0;
    padding: 1rem;
    text-align: left;
    font-size: 1.5rem;
}

a {
    color: #007BFF;
    text-decoration: none;
}

a:hover {
    text-decoration: underline;
}

a:visited {
    color: #6c757d;
}