As daft as this seems,
you will find that the control panel shows correctly so you should be able to navigate.
But edit the style sheet and do this ?
What does the style sheet look like in "EDIT" preview
hit the update button. Can you see what you think
you should be seeing?
Do this in edit mode
Name, Images & Wrapper
General Images
Change from default to dark
and submit
and then change them back again ?