This is what I was thinking. It's all just a little too bright for my taste so a little contrast would make a big difference. It took me a second to realize wh

This is what I was thinking. It's all just a little too bright for my taste so a little contrast would make a big difference. It took me a second to realize what I was supposed to do so maybe you could consider placing the "drag form elements here" box above the elements so that's the first thing the users see. I think it's really cool that you provide the code for HTML, javascript, PHP, and CSS.