title: Overlay canvas on a div with css
body: <p>On my website there is a <code>&lt;div&gt;</code> with some css styled rings in it. It's like the android unlock pattern. 9 dots which can be connected in different ways. I want to overlay a canvas on this, so that I can measure the drawing the user makes and color in the touched dots accordingly. What's the best way to overlay this?</p>