PHP getting document path relative to site root

You have to use $_SERVER["DOCUMENT_URI"] instead of $_SERVER["DOCUMENT_ROOT"] , like this:

echo "<link rel='stylesheet' type='text/css' href='" . dirname($_SERVER['DOCUMENT_URI']) . "/styles/basicblue.css'/>";

I ended substracting the web root path to get the relative one

str_replace($_SERVER['DOCUMENT_ROOT'],'',$_SERVER["SCRIPT_FILENAME"]);

So instead of /home/u/username/example.com/public_html/webfolder/index.php you will get /webfolder/index.php

edit: in constructed case your filename somehow can repeat document root, so the code above will not work correctly. This is more bulletproof (count symbols and remove them)

substr($_SERVER["SCRIPT_FILENAME"],strlen($_SERVER['DOCUMENT_ROOT']));

Echoing what Mike said above, in my experience, $_SERVER['DOCUMENT_ROOT'] is only the best option for finding files on the server. If you need php to inlcude or require something, find the server side path with DOCUMENT_ROOT.

However, css files are client side. They're included from the relative website path. If you were to instead just do

<link rel='stylesheet' type='text/css' href='/styles/newscontent.css'/>

The opening / in the href tells the browser to always retrieve it from root of your domain: http://yourdomain.com/styles/newscontent.css.