| <!doctype html> | |
| <title>CSS test reference</title> | |
| <link rel="author" title="Emilio Cobos Álvarez" href="mailto:emilio@crisal.io"> | |
| <style> | |
| .test { | |
| display: flex; | |
| } | |
| .test::before { | |
| content: ""; | |
| display: block; | |
| width: 100px; | |
| height: 100px; | |
| background-color: green; | |
| } | |
| </style> | |
| <div class="test"></div> |