Looking for a code that can be used directly for this universal interface style_html/css_WEB-ITnose

The four blocks of style code in the middle can be pasted directly.

Can someone please give me some help

Reply to the discussion (solution)

Make a page or a template?

Website management background template
Search and there are many

Used for the main interface

You can just write whatever style you want
Where can I find a common interface style

Drawn by myself