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

header {
    background: #3498db;
    color: white;
    padding: 20px;
    text-align: center;
}

nav {
    background: #2c3e50;
    text-align: center;
    padding: 10px;
}

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

nav a:hover {
    text-decoration: underline;
}

main {
    display: block;
    padding: 20px;
}

section, aside {
    background: white;
    padding: 15px;
    margin-bottom: 20px;
    border-radius: 8px;
    box-shadow: 0 0 5px rgba(0,0,0,0.1);
}

footer {
    background: #2c3e50;
    color: white;
    text-align: center;
    padding: 10px;
}