All solutions

I found it a little bit challenging to position the arches top left and bottom right I wasn't sure if the challenge required me to position them absolute to the app itself or to the window.

I also wanted to do a type in a fax on the messages but it seems that hey to requires more than vanilla CSS unless I'm mistaken I would look more into this.

I think you also need to consider accessibility by using HTML semantic tags.

What areas of improvement do you see? appreciate the feedback