Source Properties → Custom CSS → paste the CSS below
Custom CSS
How to use in OneComme
Download and unzip the pack below
Press Win + R, paste %APPDATA%\onecomme\templates\custom\ and drop the folder in
OneComme → pick template Shiori-ChatCraft
Pack contents
shiori-chatcraft.zip → Shiori-ChatCraft/
template.jsonstyle.cssindex.htmlscript.js
Already installed? Copy style.css and paste over the installed style.css. Old look stuck after that = cache — right-click the OBS source → Refresh cache of current page.
One link that restores this whole look — works for both modes.