header {
display: block;
width: 100%;
height: 150px;
max-width: 1200px;
position: relative;
margin:0 auto;
}
div.logo {
width: 150px;
height: 150px;
position: relative;
float: left;
margin:0 auto;
}
div#Reklam {
width: 100%;
height: 150px;
max-width: 1040px;
position: relative;
float: right;
background-color: #030303;
}

@media screen and (min-width: 479px) and (max-width: 640px) {
div#Reklam {
display: none;
}
div.logo {
float: none;
}
}
@media screen and (min-width: 200px) and (max-width: 479px) {
div#Reklam {
display: none;
}
div.logo {
float: none;
}
}


edit : demo adresi = http://kodarsiv.com/demo/logo-center/index.html

sanırım bu şekilde sorununuz çözülecektir hocam. :cool: