ironbar/docs/Styling guide.md

Ironbar ships with no styles by default, so will fall back to the default GTK styles.

To style the bar, create a file at ~/.config/ironbar/style.css.

Style changes are hot-loaded so there is no need to reload the bar.

A reminder: since the bar is GTK-based, it uses GTK's implementation of CSS, which only includes a subset of the full web spec (plus a few non-standard properties).

The below table describes the selectors provided by the bar itself. Information on styling individual modules can be found on their pages in the sidebar.

Selector	Description
.background	Top-level window
#bar	Bar root box
#bar #start	Bar left or top modules container box
#bar #center	Bar center modules container box
#bar #end	Bar right or bottom modules container box
.container	All of the above