CSSFontFaceRule

The cssText property of the CSSRule interface returns the actual text of a CSSStyleSheet style-rule.

The parentRule property of the CSSRule interface returns the containing rule of the current rule if this exists, or otherwise returns null.

The parentStyleSheet property of the the current rule is defined.

The read-only style property of the CSSFontFaceRule interface returns the style information from the @font-face at-rule.