*{
margin: 0px;
padding: 0px;
}
div{
width: 300px;
height: 300px;
}
#div1{
background: rgba(255,0,0,0.5);
position: relative;
left: 50px;
z-index: 2
}
#div2{
background: rgba(0,255,0,0.5);
position: relative;
left: 150px;
top: -100px;
z-index: 3
}
#div3{
background: rgba(0,0,255,0.5);
position: relative;
left: 300px;
top: -300px;
z-index: 1
}
/*
#div1{
background: rgba(255,0,0,0.5);
position:fixed;
left: 100px;
}
#div2{
background: rgba(0,255,0,0.5);
position:absolute;
left: 200px;
}
#div3{
background: rgba(0,0,255,0.5);
position: absolute;
left: 300px;
}*/
html5-相对定位
原文地址：http://www.cnblogs.com/houweidong/p/7612634.html