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

header, footer {
    text-align: center;
    padding: 10px;
    background-color: blue;
}

nav ul {
    list-style-type: none;
    padding: 0;
}

nav ul li {
    display: inline;
    margin: 0 15px;
}

nav a {
    color: white;
    text-decoration: none;
    font-weight: bold;
}

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

aside {
    width: 25%;
    padding-right: 20px;
}

main {
    width: 75%;
}

img {
    width: 100%;
    max-width: 600px;
    display: block;
    margin: auto;
}