<!DOCTYPE html> <html style="height: 100%"> <body style="height: 100%"> <table style="height: 50%; width: 50%"> <tr> <td id="x" style="position: relative; top: 25%; left: 25%"> <div style="position: absolute; left: 0; right: 0; top: 0; bottom: 0; background: green"></div> </td> </tr> </table> </body> </html>