body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
}
header {
    background: #f0f0f0;
    padding: 1rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}
nav a {
    margin-left: 1rem;
    text-decoration: none;
    color: #333;
}
main {
    padding: 2rem;
}
footer {
    background: #f0f0f0;
    padding: 1rem;
    text-align: center;
}
.btn {
    display: inline-block;
    padding: 0.5rem 1rem;
    background: #007bff;
    color: white;
    text-decoration: none;
    border-radius: 4px;
}