header {
    position: fixed;
    width: 100%;
    top: 0px;
    bottom: 85%;
    padding-left: 15px;
    color:aliceblue;
    background-color:lightslategrey;
    z-index: 10;
    opacity: 0.8;
}
aside {
    position: fixed;
    width: 20%;
    bottom: 10px;
    padding-left: 15px;
    padding-bottom: 10%;
    margin-bottom: 10%;
    background-color:aliceblue;
    z-index: 3;
}
section {
    float: right;
    width: 65%;
    bottom: 10px;
    padding-left: 15px;
    margin-right: 10%;
    margin-top: 10%;
    margin-bottom: 10%;
    background-color:white;
    z-index: 1;
}