The ::-ms-fill-lowerCSSpseudo-element represents the portion of the "track" (the groove in which the indicator aka thumb slides) of an <input> of type="range", which corresponds to values lower than the value currently selected by the thumb.
The ::-ms-fill-upperCSSpseudo-element represents the portion of the "track" (the groove in which the indicator aka thumb slides) of an <input> of type="range", which corresponds to values greater than the value currently selected by the thumb.
The non-standard proprietary ::-webkit-input-placeholderpseudo-element represents the placeholder text of a form element. This allows web developers and theme designers to customize the appearance of placeholder text. This pseudo-class is only supported by WebKit and Blink.
The :any-linkCSSpseudo-class represents an element that acts as the source anchor of a hyperlink independent of whether it has been visited, that is, it matches every <a>, <area> or <link> elements with an href attribute. So, it matches all elements that match :link or :visited.
The backdrop-filter property provides for effects like blurring or color shifting the area behind an element, which can then be seen through that element by adjusting the element's transparency/opacity.
The HTMLElement.offsetWidth read-only property returns the layout width of an element. Typically, an element's offsetWidth is a measurement which includes the element borders, the element horizontal padding, the element vertical scrollbar (if present, if rendered) and the element CSS width.