Just a suggestion, check the behaviour of the "do_it" div. If I click on it and then click outside without writing anything, the div will collapse leaving a blank area, and it will not be possible (or it will be very hard) to open it again.

I did one too before summer. Here's mine http://codepen.io/gianc/full/oLdGAv

I'm still learning, any criticism and/or advice is appreciated.