Sulfur is the 10th free XenForo style designed by Brivium, that flat, modern and simple.
1. Upload the contents of the upload directory to the root of your XenForo installation.
2. Go into your XenForo Admin Control Panel, click on Styles, and then click on "Import a Style" in the left-hand navigation list.
3. Click on the upload file field, and then navigate to and select the style-sulfur.xml file.