The transition-delay CSS property specifies the amount of time to wait between a change being requested to a property that is to be transitioned and the start of the transition effect.
The transition-durationCSS property specifies the number of seconds or milliseconds a transition animation should take to complete. By default, the value is 0s, meaning that no animation will occur.
The transition-timing-function CSS property is used to describe how the intermediate values of the CSS properties being affected by a transition effect are calculated. This in essence lets you establish an acceleration curve, so that the speed of the transition can vary over its duration.
The var() function can be used instead of any part of a value in any property on an element. The var() function can not be used as property names, selectors or anything else besides property values. (Doing so usually produces invalid syntax or else a value whose meaning has no connection to the variable.)
The CanvasRenderingContext2D.addHitRegion() method of the Canvas 2D API adds a hit region to the bitmap. This allows you to make hit detection easier, lets you route events to DOM elements, and makes it possible for users to explore the canvas without seeing it.