#div1 { position: absolute; left: 50%; top: 50%; width: 750px; height: 450px; margin-left: -375px; margin-top: -225px; }
.top {z-index:2}
.poz1 {z-index:1}
.poz2 {z-index:0}
h1 { font-size: 12px }
h2 { font-size: 10px }
p { font-size: 9px }