<!DOCTYPE html> <meta charset=utf-8> <title>Test for logical margins on h[456] elements in the UA style sheet</title> <style> .v-rl { writing-mode: vertical-rl; } .ltr, .rtl, .v-rl { border: 1px solid blue; } h4, h5, h6 { font-size: 16px; border: 1px solid purple; } .ltr h4 { margin: 1.33em 0; } .rtl h4 { margin: 1.33em 0; } .v-rl h4 { margin: 0 1.33em; } .ltr h5 { margin: 1.67em 0; } .rtl h5 { margin: 1.67em 0; } .v-rl h5 { margin: 0 1.67em; } .ltr h6 { margin: 2.33em 0; } .rtl h6 { margin: 2.33em 0; } .v-rl h6 { margin: 0 2.33em; } </style> <div class=ltr> <h4>Heading 4</h4> <h5>Heading 5</h5> <h6>Heading 6</h6> </div> <div class=rtl dir=rtl> <h4>Heading 4</h4> <h5>Heading 5</h5> <h6>Heading 6</h6> </div> <div class=v-rl> <h4>Heading 4</h4> <h5>Heading 5</h5> <h6>Heading 6</h6> </div>