Add admin section css

data/web/inc/header.inc.php

@@ -19,6 +19,7 @@
 <link rel="stylesheet" href="/inc/languages.min.css">
 <link rel="stylesheet" href="/css/mailcow.css">
 <?=(preg_match("/mailbox.php/i", $_SERVER['REQUEST_URI'])) ? '<link rel="stylesheet" href="/css/mailbox.css">' : null;?>
+<?=(preg_match("/admin.php/i", $_SERVER['REQUEST_URI'])) ? '<link rel="stylesheet" href="/css/admin.css">' : null;?>
 <link rel="shortcut icon" href="/favicon.png" type="image/png">
 <link rel="icon" href="/favicon.png" type="image/png">
 </head>