Dear Andreas,
I must apologize for this bug, it is my mistake. This is what happens if you misplace one parenthesis in the code – the header div auto-closed too soon, causing some of the css styling to be forsaken. I will definitely fix it in the next theme update, yet before that you can download this file from my repository, unzip it, and upload via FTP into the theme folder (wp-content/themes/Origami), replacing the existing file.
Thank you for reporting!
Best,
Andrew | Satori