<!DOCTYPE html> <html> <head> <title>CSS Flexible Box Test: flex-direction proprety - column</title> <link rel="author" title="haosdent" href="mailto:haosdent@gmail.com"> <style type="text/css"> /* Positioned container allows for the self-describing statement to still be visible in the case of failure */ .container { position: relative; background: red; margin: 1em 0; border: 1px solid black; } span ~ span { margin: 2em 1em 1em; } span { display: block; background: green; color: white; margin: 1em; width: 8em; } </style> </head> <body> <p>The test passed if you see all the cells are arraged vertically.</p> <div class="container"> <span>first</span> <span>second</span> <span>third</span> <span>forth</span> </div> </body> </html>