Layout shifted, what happened

Likely one of these:
https://validator.w3.org/check?uri=http%3A%2F%2Fwww.dauphinzzz.nl%2Fmiranda%2Fwordpress%2F

Your posts are stored in the database, so it would be hard to lose them from messing with your layout. If you know which file you were working on when it messed up, just re-upload your freshly saved backup (you did backup?) or a new one from the zip. When you’re modifying your theme, it’s always good to make one mod at a time and then test it and consistently backing up.