gh-24: victory screen: congratulation sound only plays once
gh-23: better favicon and apple+android touch icons
gh-8: all screen: responsive design

splash screen: fade in instead of fade out, will help avoid text changing font and logo popping in
start screen: fix blinking in Firefox & Chrome, adapt Start button size based on media queries
game screen: scale canvas to window size while preserving ratio, center vertically
victory screen: center K horizontally, flipped image no longer distorted
landscape screen: instruct to rotate to portait