body {
    font-family: Verdana, Geneva, Tahoma, sans-serif;
    font-size: 20;
}
nav {
    position: fixed;
    top: 0;
    left: 0;
    width: 220px;
    height: 100%;
    background-color: aquamarine;
    color: white;
    padding: 40px 30px;
    box-sizing: border-box;
}
nav ul {
    list-style: none;
    padding: 0;
}
nav a {
    text-decoration: none;
    color:darkblue;
    padding: 12px 4px;
    display: block;
}
main {
    margin-left: 250px;
}