* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: Arial, sans-serif;
}

header {
    background-color: #4CAF50;
    color: white;
    text-align: center;
    padding: 20px;
}

nav {
    background-color: #333;
    padding: 10px;
}

nav ul {
    list-style: none;
    display: flex;
    justify-content: center;
}

nav ul li {
    margin: 0 15px;
}

nav ul li a {
    color: white;
    text-decoration: none;
}

.container {
    display: flex;
    margin: 20px;
}

aside {
    width: 25%;
    background-color: #f4f4f4;
    padding: 20px;
}

main {
    width: 75%;
    background-color: #ddd;
    padding: 20px;
}

footer {
    background-color: #222;
    color: white;
    text-align: center;
    padding: 15px;
    margin-top: 20px;
}