<!DOCTYPE html> <html> <head> <title>CSS Writing Modes Test: margin percentage and 'vertical-rl'</title> <link rel="author" title="GĂ©rard Talbot" href="http://www.gtalbot.org/BrowserBugsSection/css21testsuite/"> <meta content="This test checks that percentages on the margin are calculated with respect to the inline-size (width) of the containing block if 'writing-mode' of such containing block is 'horizontal-tb'. In this test, div.outer's computed 'writing-mode' value is 'horizontal-tb' and it is the div.inner's containing block." name="assert"> <style type="text/css"> div.outer { background-color: blue; border: blue solid 3px; width: 200px; } hr { background-color: transparent; border: transparent none 0px; height: 3px; margin: 0.5em auto; } div.inner { background-color: yellow; height: 50px; width: 50px; -ah-writing-mode: vertical-rl; -webkit-writing-mode: vertical-rl; writing-mode: tb-rl; /* IE11 */ writing-mode: vertical-rl; } div.foo { margin-bottom: 2.5%; /* 5px */ margin-left: 50%; /* 100px */ margin-right: 25%; /* 50px */ margin-top: 10%; /* 20px */ } div.bar { margin-bottom: 10%; margin-left: 25%; margin-right: 50%; margin-top: 2.5%; } </style> </head> <body> <div class="outer"> <div class="inner foo"></div> <hr> <div class="inner bar"></div> </div> </body> </html>