Transitioning Top-Layer Entries And The Display Property In CSS

Animating from and to display: none; was something we could only achieve with JavaScript to change classes or create other hacks. The reason why we couldn’t do this in CSS is explained in the new CSS Transitions Level 2 specification:
“In Level 1 of this specification, transitions can only start during a style change event for elements that have a defined before-change style established by the previous style change event. That means a transition could not be started on an element tha