<sky>
<style>
div {
    height: 200px;
    background-color: lightblue;
}
</style>
<div id="canvas" />
<script>
import 'dart:math' as math;
import 'dart:sky';

void main() {
  var element = document.getElementById('canvas');
  element.requestPaint((PaintingContext context) {
    Paint paint = new Paint();
    paint.setARGB(128, 0, 255, 0);
    double radius = math.min(context.width, context.height) / 2.0;
    context.drawCircle(context.width / 2.0, context.height / 2.0, radius, paint);
    context.commit();
  });
}
</script>
</sky>