An excellent tool to work around theme issues that may arise.

I have used this many times in the past for sites both personal and ones I’ve worked on professionally. I’ve never had any hitches with it, and I plan to continue to use it as long as it’s available.

If it’s your first time trying it, make sure you back up the original CSS as is recommended. A few newbies I’ve recommended this plugin to forgot to do that and had a bit of a headache when they were learning to use it/work with CSS. They could have much more easily used their original theme CSS file to compare against their edits to figure out what they mangled.