Demo
This div is centered.
HTML
<header> <div id="logo"></div> </header>
CSS
header { width: 100%; min-hight: 200px; position: relative; } header #logo { position: absolute; left: 0; right: 0; margin: 0 auto; }
<header> <div id="logo"></div> </header>
header { width: 100%; min-hight: 200px; position: relative; } header #logo { position: absolute; left: 0; right: 0; margin: 0 auto; }