1：图层混排　（相对定位，绝对定位，z-index--- --父级div用相对定位position:relative，子级div用绝对定位position:absolute.当给定z-index值　时，层就开始了级别浮动．正值2，浮动到前面，负值-2，浮动到后面被遮挡．对于两个处于同一级别的层，当z-index值出现，如果想要把被遮挡的层遮挡掉一部分，就可以给它一个top的负值）



2：层背景位移　（background-position:?px ?px 给定了值就可以在任意位置移动．）



3: 层浮动后在IE6下变形　（对float:left的层给值display:inline 就这么简单）

-1: Layer shuffle (relative positioning, absolute positioning, z-index-------- relative position of the parent div with position: relative, child div with absolute positioning position: absolute. When a given z-index value, the level of the floating layer began. positive 2, floating to the front, negative-2, floating to the back was blocked. For the two layers at the same level, when the z-index values appear, if you want to be block off part of the block layer to give it a top of the negative) 2: Background layer displacement (background-position:? px? px　to set the value at any position can be moved.) 3: The floating layer after deformation under IE6 (to float: left layer to the value of the display: inline　It' s that simple)