INSTALLATION:

1. Install Stylus extension
2. Add a new style, with name "Zendesk Support History"
3. Paste the contents of stylus.css into the code field
4. Ensure that "Applies to" is set to "URLS on the domain" / 126740.apps.zdusercontent.com
5. SAVE

MORE INFORMATION:

https://heinvestigations.wordpress.com/2019/01/14/happy-suite-of-happiness-hacks/