div.nav {
    margin: 0;
    padding: 0;
    width: 15em;
    background: linear-gradient(to left, rgba(0, 153, 0,0), rgba(0, 153, 0,1));
    height: 100%;
    position: fixed;
    overflow: auto;
}

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

li a {
    display: block;
    padding: 8px 16px;
    text-decoration: none;
    color: #000;
}

li a:hover {
    background: linear-gradient(to left, rgba(0, 204, 0,0), rgba(0, 204, 0,1));
    color: white;
}

.content {
    margin: 0 0 0 15em;
    padding: 0 0 0 5px;
    width: calc(100%-15em);
    height: 100%;
    overflow: auto;
    /*border: 1px solid black;*/
}

h1 {
    color: rgb(0, 153, 0);
}