In the last year there were several discussions about the design of GlotPress. I tried to use bootstrap to make it nicer but what we really need is a complete rewrite of the theme. For this purpose I created a repo on GitHub where we can build a fresh new theme that fits our needs. Also Aris Blevins already created some mockups how the translation flow could work. This is also linked on the GitHub channel.
If you want to help out just leave a comment and check out https://github.com/GlotPress/New-Default-Theme. You can create tickets with ideas and things you would like to change.