<!DOCTYPE html> <html> <head> <!-- Note: CSS 2.1 allows guessing the static position of an absolutely positioned element whose offsets are 'auto' (initial value), i.e. the reference of this test is just one of many possible outcomes. See http://www.w3.org/TR/CSS21/visudet.html#abs-non-replaced-width --> <style type="text/css"> #in-flow-top { height: 20px; margin-bottom: 20px; background-color: green; } #abs-pos { position: absolute; width: 20px; height: 20px; background-color: blue; margin-top: 10px; margin-bottom: 10px; } #in-flow-bottom { height: 20px; margin-top: 20px; background-color: lightgreen; } </style> </head> <body> <div id="in-flow-top"></div> <div id="abs-pos"></div> <div id="in-flow-bottom"></div> </body> </html>