Resize HTML5 canvas to fit window

Question

How can I automatically scale the HTML5 element to fit the page?

For example, I can get a

to scale by setting th

Answer 1

A pure CSS approach adding to solution of @jerseyboy above.
Works in Firefox (tested in v29), Chrome (tested in v34) and Internet Explorer (tested in v11).

Link to the example: http://temporaer.net/open/so/140502_canvas-fit-to-window.html

But take care, as @jerseyboy states in his comment:

Rescaling canvas with CSS is troublesome. At least on Chrome and Safari, mouse/touch event positions will not correspond 1:1 with canvas pixel positions, and you'll have to transform the coordinate systems.