gregbell/active_admin — Issue #825: fix ActiveAdmin CSS over-riding problem 
Author: simontol
Created: 2011-12-07 20:33:00+00:00
State: open

CSS files are loaded for ALL the views (only trying in dev env). Quite annoying and will over-ride your styles. To fix just move the app/assets/stylesheets/active_admin.css.scss to vendor/assets/stylesheets/active_admin.css.scss – It is only loaded when required then.
source:
http://robertomurray.co.uk/blog/2011/rails-fix-activeadmin-css-over-riding-problem/