We'd need the html that goes with that as CSS on its own means very little and that is some complex css you have there using many negative margins so is too hard to guess what's going on.
Just post the html inside code tags in your post rather than attaching a zip as its much easier to work with that way. Or even better still provide a link to the page in question.
When the page loads, and then shifts to the left.
You will need to clarify exactly what that means and detail what happens and what was supposed to happen