id	summary	reporter	owner	description	type	status	priority	milestone	component	version	severity	resolution	keywords	cc
18314	Merge admin CSS files and remove duplicates	azaozz		"Looking through wp-admin/css we have large amount of stylesheets that aren't optimized neither for loading nor for maintenance/consistency.

Generally we have two options: either to break our CSS into smaller chunks of dependent styles and load different amount on each screen or to ""globalize"" it all into wp-admin.css and wp-admin-rtl.css.

The second option would be (quite?) better for faster loading. Currently we concatenate and compress the admin css but since the files are different for most screens, the concatenated file has to be downloaded each time. If all admin styles are in one file it will be cached by the browser after the first time (in memory) and all subsequent loads will be faster.

To do:
- continue removing duplicate and nearly duplicate styles from wp-admin.css
- after that's in good shape, do the same for wp-admin-rtl.css

Please see [https://core.trac.wordpress.org/ticket/18314#comment:14 comment:14] "	task (blessed)	closed	normal	3.3	Performance		normal	fixed		sabreuse@… ryan@… tom@… olleicua