Put this in your quickcss or any theme replacing (filename) with the name of css file.

For snippets: @import url("https://uzamapg.github.io/PC-theme/snippets/**filename**.css");

For themes: @import url("https://uzamapg.github.io/PC-theme/simple-themes/**filename**.css");

None of the snippets are made by me apart from some stuff in the hide-stuff.css. All the stuff is found in the Powercord Discord server.