body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
}
header {
    background-color: #4CAF50;
    color: white;
    padding: 20px;
    text-align: center;
}
header h1 {
    margin: 0;
}
nav ul {
    list-style-type: none;
    margin: 0;
    padding: 0;
    overflow: hidden;
    background-color: #333;
}
nav li {
    float: left;
}
nav li a {
    display: block;
    color: white;
    text-align: center;
    padding: 14px 16px;
    text-decoration: none;
}
nav li a:hover {
    background-color: #111;
}
main {
    padding: 20px;
}
footer {
    background-color: #4CAF50;
    color: white;
    padding: 10px;
    text-align: center;
}