body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
    text-align: center;
    background-color: #f5f5f5;
}
header {
    background: #007bff;
    color: white;
    padding: 20px;
}
nav ul {
    list-style: none;
    padding: 0;
}
nav ul li {
    display: inline;
    margin: 0 10px;
}
nav ul li a {
    color: white;
    text-decoration: none;
}
section {
    padding: 20px;
    margin: 20px;
    background: white;
    border-radius: 10px;
    box-shadow: 0px 0px 10px gray;
}
button {
    padding: 10px 20px;
    background: #007bff;
    color: white;
    border: none;
    cursor: pointer;
}