CSSRule NewRule Method
Create a new CSSRule.
R←{I} NewRule X
X is the selector. I in an optional parent CSSRule. R is a new CSSRule instance.
Examples
r←A.NewRule 'h1'
r
CSSRule
r.font_size←'2rem'
r.padding←'.5rem'
A.ComposeRules r
h1 {
font-size: 2rem;
padding: .5rem;
}