2020
1 featuresThe CSS.escape() static method escapes a string so that it can be used in a valid CSS selector.
2015
2 featuresThe CSS object model API reads, creates, and modifies CSS stylesheets and inline styles. Also known as CSSOM.
The getComputedStyle() global method returns an CSSStyleDeclaration object that represents all CSS declarations applied to a given element.
Limited Availability
4 featuresA CSSPseudoElement object represents a pseudo-element and its context in the document tree. You get an instance through the pseudo() method of Element or CSSPseudoElement objects or the pseudoTarget property of some events.
The CSSStyleValue and its subclasses represent CSS values as distinct types instead of only strings. Also known as typed OM.
The numeric factory functions, such as CSS.px() or CSS.kHz(), return a CSSUnitValue representing a CSS number value (as in 12px or 440kHz).
The DOM level 2 style specification defined interfaces to access and modify CSS styles, such as CSSValue and CSSPrimitiveValue, that were later excluded from the CSS object model.