Thanks for your code! It helps a lot. We also added to the styles a Relative and Absolute position to fix the top alignment. I hope this can be also useful for others... Let's see if Adobe can come up with a solution on their next update.
<style>
body {
margin: 0;
position: relative;
}
canvas:hover {
cursor: pointer;
cursor: hand;
}
canvas {
position: absolute;
top:0px;
left:0px;
}
</style>