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

header {
    background-color: #333;
    color: white;
    padding: 1rem;
    text-align: center;
}

nav {
    margin-top: 1rem;
}

button {
    background-color: #555;
    color: white;
    border: none;
    padding: 0.5rem 1rem;
    margin: 0 0.5rem;
    cursor: pointer;
    border-radius: 4px;
}

button:hover {
    background-color: #777;
}

main {
    padding: 2rem;
}

#content {
    background-color: white;
    padding: 1rem;
    border-radius: 8px;
    min-height: 400px;
    box-shadow: 0 0 10px rgba(0,0,0,0.1);
}