Wikimedia Developer Support

How do I style MediaWiki's DateInputWidget?

I’ve written an oojs-ui theme for my MediaWiki skin. However I can’t seem to find DateInputWidget anywhere in the demo for oojs-ui. Simply adding CSS to my skin directly to override doesn’t work since the widget’s styling is inline. How do I style the widget?

References:
https://www.mediawiki.org/wiki/OOUI/Themes

Like an idiot I thought it was a OOJS widget, but it’s a MediaWiki widget. Updating styles using ResourceModuleSkinStyles in skin.json fixes this issue.