window.getComputedStyle
Returns an object containing the values of all CSS properties of an element, after applying active stylesheets and resolving any basic computation those values may contain.
Returns: CSSStyleDeclaration - - A live CSSStyleDeclaration object, which updates automatically when the element's styles are changed.
See: window.getComputedStyle  
| Param | Type | Description | 
|---|---|---|
| element | Element | The Element for which to get the computed style. | 
| pseudoState | string | A string specifying the pseudo-element to match. Omitted (or null) for real elements. | 
