Menu left, Logo Center, Menu right

Hello!

Why dosn’t work this code? The logo is center, but the menu buttons on logo.
Header settings is: logo left, menu, right,
Header Style: Minimal with drop shadow (no borders, indicators or transparency)
i have 4 menu buttons.

Thanks for your help!
Zsolt
/*————————/
/ CSS – Logo center split menu
/*————————/

@media only screen and (min-width: 780px) {
/*In the below code nth-child(x) the value of x should be half the number of total menu items*/
#top #header .av-main-nav li:nth-child(3) {
/ Adjust the width of the logo */
margin-right:150px;
}

#header .main_menu {
/*background: gold;*/
width: 100%;
left: 50%;
transform: translateX(-50%);
}

.av-main-nav-wrap {
left: 50%;
transform: translateX(-50%);
}

#header .logo {
left: 50%;
transform: translateX(-50%);
z-index:999;
}

#header .logo img {
top: 50%;
transform: translateY(-50%);
max-width: 100px;
}
}