<!DOCTYPE html> <meta name="viewport" content="initial-scale=0.5,width=device-width"> <style> html, body { margin: 0; width: 100%; height: 100%; } #container { position: relative; } #inner { position: absolute; top: 0; right: 0; width: 100px; height: 100px; background: green; } </style> <div id="container"> <div id="inner"></div> </div>