* {
    box-sizing: border-box;
}

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

header {
    background: #222;
    color: white;
    padding: 20px;
    text-align: center;
}

nav {
    background: #333;
    padding: 12px;
    text-align: center;
}

nav a {
    color: white;
    text-decoration: none;
    margin: 0 15px;
    font-weight: bold;
}

nav a:hover {
    color: #4da6ff;
}

main {
    max-width: 1000px;
    margin: 40px auto;
    padding: 30px;
    background: white;
    border-radius: 10px;
}

footer {
    text-align: center;
    padding: 20px;
    color: #777;
}