<!DOCTYPE HTML> <html reftest-zoom="0.8"> <head> <style> div { margin:1em; } /* A 7x7px image, black with a 5x5 transparent box centered in it */ div.box { background-image:url(data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAcAAAAHCAYAAADEUlfTAAAAFklEQVQImWNgYGD4jwdDCCxgQCWxYgBX8hfpeym4dwAAAABJRU5ErkJggg==); } /* A 7x5px image, black with a 5x5 transparent box centered in it */ div.vstrip { background-image:url(data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAcAAAAFCAYAAACJmvbYAAAAFElEQVQImWNgYGD4z4Ad/GcYAEkAw+kJ94z5rSYAAAAASUVORK5CYII=); } /* A 5x7px image, black with a 5x5 transparent box centered in it */ div.hstrip { background-image:url(data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAUAAAAHCAYAAADAp4fuAAAAE0lEQVQImWNgYGD4jwXTD2DYDgDN4Qn3yMcPlwAAAABJRU5ErkJggg==); } </style> </head> <body> <div class="box" style="background-position:-1px -1px; width:5px; height:5px;"></div> <div class="vstrip" style="background-position:-1px 0px; width:5px; height:22px;"></div> <div class="hstrip" style="background-position:0px -1px; width:22px; height:5px;"></div> </body> </html>