body {
    font-family: 'Segoe UI', sans-serif;
    background: #f9f9f9;
    color: #333;
    margin: 0;
    padding: 0;
}
header, footer {
    background: #1e1e1e;
    color: #fff;
    text-align: center;
    padding: 1rem;
}
nav {
    background: #333;
    color: #fff;
    padding: 0.5rem;
    text-align: center;
}
nav a {
    color: #fff;
    margin: 0 15px;
    text-decoration: none;
}
nav a:hover {
    text-decoration: underline;
}
.container {
    max-width: 900px;
    margin: auto;
    padding: 2rem;
    background: #fff;
}
a {
    color: #0077cc;
}