CSS有四种定位(Positioning)方法:Static,Relative, Absolute和Fixed 元素flow, overlap 相对参照物: 能否用offset( top, left, bottom, right)参数 是否移出 normal flow 是否可以 overlap 备注 Static 缺省的, normal flow 忽略 No Relative its own normal position √ No Yes 常用作 Absolute元素的container Fi…