Описание тега will-change
NoneWill-change is a CSS property, which allows an author to inform the user agent ahead of time of what kinds of changes they are likely to make to an element.
This allows the user agent to optimize how they handle the element ahead of time, performing potentially-expensive work preparing for an animation before the animation actually begins. CSS is a language for describing the rendering of structured documents (such as HTML and XML) on screen, on paper, in speech, etc.