.margintop
{
    flex-basis: 47.5%;
    flex-grow: 1;
    margin: 10px;
}

#herum
{
    position: absolute;
    top:100px;
    left: 0;
    right: 0;
    margin: 0 auto;
    padding: 10px;
    background: rgb(5,5,5); /* Old browsers */
    background: -moz-linear-gradient(left,  rgba(5,5,5,1) 1%, rgba(237,201,0,1) 99%); /* FF3.6-15 */
    background: -webkit-linear-gradient(left,  rgba(5,5,5,1) 1%,rgba(237,201,0,1) 99%); /* Chrome10-25,Safari5.1-6 */
    background: linear-gradient(to right,  rgba(5,5,5,1) 1%,rgba(237,201,0,1) 99%); /* W3C, IE10+, FF16+, Chrome26+, Opera12+, Safari7+ */
    max-width: 800px;
    height: 400px;
    display: flex;
    flex-wrap: wrap;
}