-Styles must be improved (full width for smartphones, selectable text for PGN...)
-Tooltip text should fade (even when mouse stay on it, especially for small screens)
-Checkered stage 2: switch button at reserve position.
-If a played disconnect right after opponent sent a move, it might be never received: secure this
+Finish rules translation in Spanish
+Design: final touch (gain extra space on top, using space on the right)
+Crazyhouse: center reserves, grey if zero available, numbers superimposed