All font sizes are rem-based, meaning that they are multiples of the document's root font size.
These are the predefined font families. A font family is a list of font faces by order of priority.
If the first font face is not installed on the user's operating system, the next one will be used instead.
Open Sans, Verdana, DejaVu Sans, Arial, Helvetica, sans-serif
Open Sans, Tahoma, Geneva, Arial, sans-serif
The line height determines the total height of a line.
Line heights are calculated as multiples of the font size.