body {
      background-color: mediumseagreen;      
}


header {
        background-color: indianred;
        height: 200px;
}

nav {
     background-color: 	lightsteelblue;
     float: left;
     width: 25%;
     height: 300px;
}


article {
	float:left;
        background-color: white;
        width:50%; 
        height: 300px;    
}

aside {
       background-color: moccasin;
       float: left;
       width: 25%;
       height: 300px;      
}

footer {
    background-color: gainsboro;
    position: fixed;
    bottom: 0;
    width: 100%;
    height: 100px;   
}