Fix a variety of minor issues

CSS:
- use integer values for font-size in CSS
- use correct ordering of @import
- "invisible" isn't a tag - presume its a class
- "border-color" defines the complete border

python:
- use "not" instead of == "[]" for python
- prefer triple quoted docstrings
- prefer static functions where possible
- prefer modern style classes where possible
- remove semicolons;

global:
- remove duplicated words words