- It is very impressive to me and I believe animation will get hot soon next year, read this and this posts and take some time to try GSAP.
- A pure CSS toggle button in jsFiddle
- Awesome examples: please take a few min to look at this site to feel how powerful CSS animation is.
- Viewport units: vw, vh, vmin, vmax
- Test how mobile-friendly your site is using this tool
- What you can do with CSS level 4 selectors