[Satan]

I think it's pretty cool
Thanks for the suggestion, I'll keep this chrome extension to customize websites my own way

Alrighty.
Just remember it uses CSS, and declares your CSS before the site's own, which is how it replaces it. You don't need any custom strings like if(code)replacewith(this) or anything like that, just declare the CSS you want your specific site in the addon, and it will add it for you.
If you need help with something, just send me a PM and I'll do what I can.