Add configurable duration to `invisible-until-active` mixin

New syntax for quick "invisible until active" elements + configurable transition duration (defaults to 500ms):

div {
  @include invisible-until-active(200ms);
}

<button id="myButton">Show Element</button>
<div id="myElement">Look, I faded in!</div>

myButton.addEventListener('click', (event) => myElement.classList.add('is-active'));

More Details

• PR 33: Add configurable duration to invisible-until-active mixin
• CHANGELOG