Seems like you’ve done something with it, now the page is very broken.
Anyway, biggest problem probably happened because there is div.container within #logo and div.container has 960px width, so when you (I guess) set `position: absolute;` to #logo it also made #logo to jump on top of the #mainmenu.
Easiest solution would’ve been to give #mainmenu a `position: relative;` or remove container class from the div (although that may give some other issues).
1- within your body, add a div of class “container” instead of giving the “container” class inside menu & slider & loop :
2- remove the “container” class within the above mentionned
3- create a element to encompass your logo + menu
4- cleanup: unset margins, width, floats on logo and menu and ul#mainmenu-menu, add theme back one at a time only if needed
5- display:block; your logo
6- float your logo and your menu left
7- remove margin-top: 30px; on the slider ?