body{
    margin:0;
}
header{
    background-color : lightpink;
    position : sticky;
    text-align : center;
}
footer img{
    width :30px;
    height :30px;
}
img{
    width :100px;
    height :100px;
}
main img{
    width :200px;
    height :150px;
}
article{
    border :2px solid #DDD;
    padding:1em;
    width :80%;
    background-color : lightgrey;
    margin : auto;
}