Calc ()-CSS3 new properties that can be computed

Usage:
Width:calc (100%-(20px + 2px) * 2);  /* Use 100% minus two 20px padding and 2px border*/

For Calc (), summarize the following points:

1. Compatibility: In ie9+, ff4.0+, chrome19+, safari6+ support is good, mobile side support is not ideal;

2. The expression supports addition, subtraction, multiplication and subtraction, and also supports mixed use of units (%, px, EM, etc.);

2. In the expression, there must be a space before and after the "+", "-" operator.

Calc ()-CSS3 new properties that can be computed