Hi,
If you use proper class name, regardless of the CSS file you use, your rules must be effective. But if user.css is loaded BEFORE the flexible.css file, then you need to use "stronger" rules to override the old rule (or use
!important parameter, but it is not recommended)
For instance
div.className { color:red; }
or
.parentClass .className { color:red; }
are stronger, thus they override the
.className { color:white }
you see what i mean? To avoid this confusion, and to use the "same" rules that were presented in the flexible.css, then you must have user.css file gets loaded on the page AFTER flexible.css gets loaded.
Are you working in a live server? I need to open your website to see what you did.
Regards