This was just a fun experiment to see if I could do this. I use jQuery for the animation, and CSS3 for the scale transform of the entire content area. The effect is one where the content area ducks into the background and a new content area slides in (from one of four directions). Certainly could use some re-factoring, but I'm pleased with how it turned out.
A layout powered with flex and with transitions.
Found an beautiful demo from Tympanus.com(Codrops). But honestly I didn't fully understand the Js they used. So I attempted to simplify it a bit.
Growing (resize) a textarea for comfortable text entry
A collection of hover effects for menus, using CSS3 transitions.
I am a little ashamed to admit I have not used CSS transitions or animations in nearly 2 years. Here is part of my attempt to re-learn tem. Hope to have a more polished pen next project!