Banner moves to the other site

Hallo!

I've made a new menu on my website: www.vie-la-mort.forum-motion.com

And the menu is centeret on my computer, but on some of the users its going a little to the left.
Is it possible to make the menu centeret on every screen?

This is the users screen picture

Code:

a.mainmenu{
font-family: Bookman Old Style;
text-shadow: 1px 1px 2px #000;
border-top:1px solid:#222;
-webkit-transition:0.400s;
-webkit-border-radius:5px;
margin:0px -10px 0px -10px;
-moz-border-radius:5px;
-o-border-radius:5px;
border-radius:0px;
font-size: 13px;
padding:15px;
color:#ddd;
}
a.mainmenu:hover{
-moz-box-shadow: 0 0 5px 5px #507495;
-webkit-box-shadow: 0 0 5px 5px #507495;
box-shadow: 0 0 5px 5px #507495;
border:1px solid:#000;
background-color:#0B2161;
}
ul.navlinks {
position:relative;
border:none;
}
.navbar {
background-color:rgba(0,0,0, 0.6);
position:absolute;
height: 40px;
width:90.3%;
clear:both;
right:100px;
top:350px;
left:59px;
}

Hello IdaTR,

Try removing the width property. Since its absolutely positioned, we can allow the browser to define its dimensions by setting left and right. Like below:

Code:

.navbar {
background-color:rgba(0,0,0, 0.6);
position:absolute;
height:40px;
clear:both;
top:350px;
right:4%;
left:4%;
}

The navbar will be 4% away from the users browser window on both sides. If the issue still occurs try increasing the percentage. If that doesn't work we can try relative positioning.

The only thing you'll need to fix looks to be the .navbar, everything else looks perfect.

solved (: