How to solve dropdown menu problem.

Please look and help me how to solve this

I want look like:
http://s22.postimg.org/mk0d7u5e9/image.png”

But my code show :
On Chrome:
http://s4.postimg.org/sj36cml9p/image.png
On mozilla
http://s21.postimg.org/5uv90xhaf/mozilla.png

Website link here http://markcdm.tk/1
Please help me to do this.
Thanks