Popup Menu is cut off in Firefox
Issue summary
The Popup Menu that is used since MTA 2.0 is not shown correctly when using Firefox.

MTA will notify users with a red button of this issue after they login. Clicking the button will lead them to the solution described below.
Possible causes and resolutions
This popup menu is using the has selector in CSS.
This feature is enabled by default in Chromium browsers, and disabled by default in Firefox.
Most other browsers do not support the feature.
Resolution
To enable the feature in Firefox:
- navigate to
about:configin your Address bar - search for
has-selectorlike this:
- then, make sure to set the
layout.css.has-selector.enabledproperty to true. - restart Firefox and go to MTA to check the menu is working correctly.
More documentation about the has selector on Mozilla: https://developer.mozilla.org/en-US/docs/Web/CSS/:has