2 options:
1. Set viewport to device-width and make sure to use % widths
2. Set viewport to the width of your container/wrapper (+ some padding if needed). When using this option you want to allow the user to zoom in and out as text and such may be too small to read.
As for your demo here is your problem:
.dragboard {
position: absolute;
width: 1000px;
height: 585px;
}
You must use % based widths to make the element fit the viewport. It fits the iPad because the iPad screen is that size (768×1024, or double for retina screens)