@media screen and (max-width: 400px) {

body {width: 100%;
margin-right: 0px;
margin-left: 0px;
}
header {
text-align: center;
}
nav li {
    font-size: 18px;
    display: block;
    width: auto ;
    text-align:center;
    
    
    }

section {
float:right;
width: 100%;
padding: 0px 0px;
}
aside {
width: auto;


float: left;

height: auto; 

}

footer {

float: left;

height: 40px ;
font-size: medium ;
text-align: center;
width: 100%;
}


}