Navigation moves when its to little text :/

Hi, im making a simple html website for school project index is good but when i copyed it and made a galery.html it seems that my navigation to the right moves

Here is index


And here is the messed up gallery, look to the right off the text Ne


Its supposed to be finished by tomorrow so if someone could help me that would be apriciated, if u need any code just shout

 

Um , I don't think we could begin to find a solution with out code.