CSS
- CSS Grid Layout
- Definition List Formatting
- Float and Clear (Divs)
- Google Fonts
- HTML/CSS Markup Validation Service
- Layers CSS - Platform Independent CSS Model
- Margins
- Paletton Web Color Picker
- Tables
- Text-orientation (for rotating text)
- W3C Schools - Color Picker
- W3C Schools - CSS
- Writing Move (for rotating text)