The CSSStyleRule interface represents a single rule set in a CSS style sheet.

The textual representation of the selector for the rule set. The implementation may have stripped out insignificant whitespace while parsing the selector.

SYNTAX_ERR: Raised if the specified CSS string value has a syntax error and is unparsable.

NO_MODIFICATION_ALLOWED_ERR: Raised if this rule is readonly.

The declaration-block of this rule set.