Hi Katarina,
Definitely a CSS issue, I think (without reading the code) the landing page thinks the form is bigger than the stated size - try deleting the form, readding it and then working through the CSS line by line on the formatting you desire.
Regarding the fields being bunched together, that's just looks like a case of buggy formatting when using CSS - have you copied/pasted from another location the styles? Try pasting it into a .RTF first so no formatting from its source is pulled as well?