Hi bluemi!
If I get it right the same issue was brought up sometime before. Much water has flowed under the bridges since then ?? Document Gallery has considerably evolved and our suggestion also has changed a bit. I see there is no need to guiding You where to put the stated CSS, but for the sake of not that advanced users.
Given below CSS should be pasted in the Custom CSS textbox at Dashboard -> Settings -> Document Gallery:
.document-icon-row.descriptions {
vertical-align: top !important;
display: inline-block;
width: calc(100% / 6 - 1%);
}
.document-icon-row.descriptions .document-icon {
float: none !important;
width: 100% !important;
margin: 5px auto 0px;
display: block;
}
.document-icon-row.descriptions p {
font-size: xx-small;
text-align: justify;
}
As the descriptions option (while being set to true) prevents Document Gallery from utilizing columns value, You should set it Yourself by editing line width: calc(100% / N - 1%);
where N – is the number of items in a row.
Hope this will do the job.