Some CSS styles I wrote for HumHub.
Open your browser and install any CSS injector tool. For Chrome I use Magic CSS, it's the easiest to use that I've tried. For Firefox I use CustomCSS Injector... although I might try something else cause it's got some stuff that annoys me.
It doesn't really matter what CSS injector you use, just open it up and paste in the entire contents from either style.css or the newer stylev2.css files.
The CSS is a bit better now but it still doesn't override all styles, some places you visit (settings, etc) might look a bit janky. It doesn't really bother me because I rarely visit those places anyways. It also hides some stuff on the main dashboard page that I found annoying and centers the content which I like.
If you use Magic CSS you can use the style.sass file as it supports CSS, Sass, and even Less.
If not and you want my testing styles you can use compiled.css which has the compiled version of style.sass