.Bilder_ {
    padding: 10px;
    max-width: 300px;
    max-height:150px;
    vertical-align: bottom;
    display: block;
    margin-top:auto;
    margin-bottom:auto;
    margin-left:auto;
    margin-right:auto;

}

.Videos_ {
    padding: 10px;
    max-width: 300px;
    max-height:150px;
    margin-top:auto;
    margin-bottom:auto;
    margin-left:auto;
    margin-right:auto;
    display: block;
}


.kasten{
background: #555555;
margin-left: 10px;
margin-bottom: 10px;
border: 5px solid grey;
float:left;
width: 300px;
height: 250px;
    }
body{
background: #676767;
}