@wpyogi The file structure is correct, the customizr child folder is directly in Themes, not a sub-directory of customizr.
@acub Removed the @import, and as you assumed, it didn’t change anything. I’ll try to search around and see why it could be adding a backslash to the code.
To follow this up, the CSS code worked for the home page but I can’t seem to get it to apply to other pages – the white box remains under a large portion (albeit smaller than before). Am I missing something simple here?