a.messageclose {
    position: absolute;
    right: 10px;
    top: 6px;
    background-image: url(/images/X.svg);
    background-size: contain;
    background-repeat: no-repeat;
    width: 15px;
    height: 15px;
}

a.messageclose:hover,
a.messageclose:focus,
a.messageclose:active {

}