Performance of CSS Transitions

I'm going to say maybe on that one... I haven't looked at the code in detail. But as you said, the only difference are ease-in-out and multiple transitioning. You can absolutely do two transitions at the same time.

I'm using this one. There are a overlay fading and opening of a modal in this demo, see if it's lagging.
https://adminlte.io/themes/AdminLTE/page...odals.html

The only thing that differs (if you don't count position, color...) are that they specify all web browser standards.

Code:

-webkit-transition: right .3s ease-in-out;
-o-transition: right .3s ease-in-out;
transition: right .3s ease-in-out;