If e.g description of a one library is very long, drop-down filters in item holdings table stretch to match the width of this description. This can lead to table to stretch over screen especially if a lot of columns are displayed. Although this happens even without filters turned on but we shouldn't make the matter worse. We should add rule which makes drop-downs width to be consistent. To reproduce: 1. Modify one library description to be a lot longer than other descriptions. 2. Find an item with current or home library in this library. 3. Navigate to detail page of items biblio. 4. Click "Show filters" on holdings table. => Note that drop-down filters width is as long as your very long library description.
I wonder if this is enough to accomplish what you're describing: th .dt-select-filter { max-width: 12rem; }