Avoid to load code by cdn, much better local code

Adopt a code nomenclature that you like and stick on it, camel case is usually not suggested for css

Avoid specific browser code that is prone to incompatibilities and short time expiration

Be rigorous, better classes for grouped elements only, otherwise identities

Tagging it by an initial "/*" and a final "*/" is the only way to comment out part of your code

Keep your stylesheets ordered and clean for most what you can

Javascript code can dynaically change css values