Display files in line on item pages

Is there a way to display the files in the item page by line instead of vertical arrangement?
For example :

Thanks a lot for your help!!

That could probably be done by adding a CSS rule like

.item-files {
float: left;
margin: 2px;

Some themes also include a configuration option for displaying a gallery, but I don't think that's in your current theme.

Thanks for your answer and your help!
It's working but it's not ".item-files" but ".item-file" without the s (if someone else is interested by that).

My bad, and good catch!

No problem thanks for your help!