CSS linear-gradient getting removed

[Nisala Kalupahana]

For some reason, Confluence isn't letting me add a linear-gradient background CSS.

Steps to reproduce:

• Create a Confluence page
• Edit the page, go to the Source Editor, and enter "<div style="width: 100.0px;height: 100.0px; background: linear-gradient(90deg, rgba(17,199,208,1) 0%, rgba(17,199,208,1) 11%, rgba(255,255,255,1) 11%, rgba(255,255,255,1) 100%);">Test</div>"
• Click Apply, and the gradient will appear in the preview window.
• If you now Save, Preview, or re-open the Source Editor, the CSS for the linear-gradient will be gone. It just completely disappears, and seems to be replaced with "<div style="width: 100.0px;height: 100.0px;">Test</div>".

Any guidance on what's going on here would be greatly appreciated -- I have no idea what's going on. 

[Brant Schroeder]

@Nisala Kalupahana Welcome to the Atlassian Community

I would suggest adding class to the page <div class="gradient"</div>  Confluence will remove certain reserve characters.  Then add your styles to the global stylesheet or custom html in general configuration.