The animation property of an AnimationEvent or TransitionEvent object is the Animation object that represents the animation (and thus the element) that fired an animation event.

The progress() CSS function returns a ratio for the relative position of one value between two other values, clamped between 0 and 1. You can use it to interpolate a value for other calculations.

The sibling-count() and sibling-index() CSS functions return integers that are useful to style elements based on their positions among siblings or on the number of siblings, for example as part of a calc() expression.

The field-sizing CSS property allows form controls such as <textarea> to be sized based on their content.

The @scope CSS at-rule sets the scope for a group of rules.

The font-family: math CSS declaration uses the browser default font face for displaying mathematical expressions.