<!DOCTYPE html> <meta charset=utf-8> <title>Test for logical margins on h[123] elements in the UA style sheet</title> <style> .v-rl { writing-mode: vertical-rl; } .ltr, .rtl, .v-rl { border: 1px solid blue; } h1, h2, h3 { font-size: 16px; border: 1px solid purple; } </style> <div class=ltr> <h1>Heading 1</h1> <h2>Heading 2</h2> <h3>Heading 3</h3> </div> <div class=rtl dir=rtl> <h1>Heading 1</h1> <h2>Heading 2</h2> <h3>Heading 3</h3> </div> <div class=v-rl> <h1>Heading 1</h1> <h2>Heading 2</h2> <h3>Heading 3</h3> </div>