CMS pro uses several cachef olders in order to speed up page loading time. Instead of loading multiple css and javascript files, all files are compressed and loaded as one single file.

When modifying css files do not change anything in /view/admin/cache/ or /view/front/themes/current_theme/cache/

Instead modify individual css files located in /view/admin/css/ or /view/front/themes/current_theme/css/

Cached file master_main.css will be automatically updated.