Do you really need a hint for this one?
LEVEL 2:Think outside the website's borders, let your mind think!
LEVEL 3:Is anything wrong? Try going to the opposite direction.
LEVEL 4:If the sun is the source of light, what is the source of this page?
LEVEL 5:Use your head. Is there anything similar in the website?
LEVEL 6:Just check the tab, it says what you should do.
LEVEL 7:The numbers are positions, 1-14.
LEVEL 8:The base n°64
LEVEL 9-30:You're now on your own! There won't be any hints from me past this point