Those files ?
I changed only one file.
Just use those commands I gave you, it saves you time.
I'm glad the page updates on the fly, but better safe than sorry. But that goes to show that a .css file can't add containers to a page... For that, you need access to the theme's source code.
By that I meant that when you change luci webpage files, you need to perform those steps otherwise changes will not reflect in your browser session.
Solved changing file:
/usr/share/ucode/luci/template/themes/material/header.ut