Other references.

Miscellaneous references.

• Blend modes
  List of blending modes, or how to combine two overlapping images.
• Colors
  How to define a color in CSS, in the different color spaces: RGB, HSK, HWB, etc.
• Color chart
  Among the thousand and one ways to express a color in CSS, there are named colors.
• The entities
  How to print special characters in HTML and CSS.
• Priorities
  When two rules contradict, how CSS decides which one to use.
• Units
  In CSS, numeric values are often followed by a unit. Here is the list.