Thanks a lot! Worked peferct 
Just one little problem is the margin-top of the h4 on this page: https://bueronerds.de/fokus/test-datenbank/
There seems to be little to none margin between the cards and the H4s. In my stylesheet, I have added this css-code for the cards:
.card {
position: relative;
float: left;
display: block;
width: 240px;
margin: 0.1rem;
background-color: #fff;
border-radius: 0.25rem;
border: 1px solid rgba(0, 0, 0, 0.125);
}
.card-title {
margin-bottom: 0.6rem;
}
.card-block {
padding: 0.6rem;
}
Do you see the problem or can you help me, to have a bigger margin between the h4 and the cards?