i`d like to change the layout of the gallery (colors, size of tables etc...) but idon`t know how to do i. can sombody help me with that?

There is a css file in the theme directory. This is where you will make most all of your changes.. If you dont know how to modify css, there are tons of online tutorials but css is how you are gonna want to start...

i konw a bit css, but when i`ve changed some tags in there, only admin panel`s changed, what i did wrong???

OH, I think i found this file ->zen.css