Timeline header behaviour different on Firefox and WebKit.
On Firefox, the clickable part of the timeline header is limited to the arrow icon; on WebKit-based browsers, it extends farther to the right.
This should be unified, preferably customizable, as some may want one behaviour while others may desire another.
Firefox:
pleroma-fe-tl-header-fx-2021-12-12_22.08.32
Konqueror:
pleroma-fe-tl-header-konqueror-2021-12-12_22.09.25
Safari behaves the same as Konqueror.