Class Settings Not Applying to Group Box

I have a group box that I would like to have a yellow banner and black text for the title and “+” icon.  I have created a class for this purpose, but it doesn’t apply those settings to the group box.  Any ideas why this isn’t working?  Here is a picture of my class:   Here is what I put in the group box class property:
1 answers

The best thing you can do is to access the dev tools (often f12 in you keyboard) to view your container from your browser.
From there you can find out why your class isn't working.

There are multiple reasons why this isn't working like that your custom class isn't loaded (not imported in the main scss) or that other classes are overwriting your values.

Getting to know and work with dev tools is (almost) mandatory when you like to customize your styling