I love the idea of CSS-only code, unfortunately on Win7 Firefox Aurora (alpha) & Chrome beta there is only a mouse-over ripple & no mouse-click interaction. From what I can tell from the video, the button should 'raise up' (z-plane transform towards the front of screen) on mouse over & tap, & the ripple should only work on click/tap.
Also, the ripple should originate from position of the mouse or finger. Likely will have to do overflow: hidden for lower layer...
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