*{margin: 0;}

body{box-sizing: border-box;background-color: azure;width: 100vw;}

header{box-sizing: border-box;background-color: #ff9f1c;width:100vw;height:10vh;border:1px solid blue;}

nav{box-sizing: border-box;background-color: #ff9f1c;width:100vw;height:10vh;border:1px solid blue;}

section{box-sizing: border-box;background-color: white;width:100vw;height:70vh;margin: 0;padding: 0;}

aside{float:left;box-sizing: border-box;background-color: #2ec4b6;width:20%;height: 70vh;}

article{float:left;box-sizing: border-box;background-color: #ffe5d9;width:30%;height:70vh;border: 1px solid red;}

ul{list-style-type: none;}

li{box-sizing: border-box;float: left;background-color:#2ec4b6;padding:20px;color:white;}

footer{float: none;display: block;box-sizing: border-box;background-color: black;color:white;width:100vw;height:10vh;border:1px solid blue;}