<!DOCTYPE html ><title>Only one 300px*300px green quadrate. No red</title ><body style="overflow: hidden; max-width: 800px; max-height: 500px;" ><h1>Only one 300px*300px green quadrate. No red.</h1 ><table style="writing-mode: sideways-lr; width: 100px; height: 300px; background: red; border-spacing: 0px; border: 0;" ><tr ><td style="width: 300px; background: green; color: white; padding: 0; border: 0;"></td ></tr ></table ></body>