/* Le code CSS de la démo */
.padding{
    padding:1em;
}
.parent{
    border : 1px dashed orange;
    padding: 1em;
    margin : 0px;
    background: #eee;
    
}

.parent article{
    width : 50%;
    float:left;
    
}

.overflow {
    overflow:auto;
}

.clear{
    clear:both;
    border-bottom: red solid 4px;
}

.clearfix::after {
    content:"";
    display:block;
    clear:both;
    border-bottom:4px solid purple;
}