CSS Positioned Layout is a module of CSS that defines how to position elements on the page. Reference CSS properties bottom clear display float left position right top z-index Guides Understanding CSS z-index Presents the notion of stacking context and explains how z-ordering works, with several examples. Specifications Specification Status Comment CSS Positioned Layout Module Level 3 Working Draft CSS Level 2 (Revision 1) Recommendation Browser compatibility Desktop Mobile Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari (WebKit) Basic support 1.0 1.0 (1.7 or earlier) 5.0 6.0 1.0 (85) Feature Android Firefox Mobile (Gecko) IE Mobile Opera Mobile Safari Mobile Basic support 1.0 1.0 (1) (Yes) (Yes) (Yes)