Change
<link rel="stylesheet" href="./css/css.css">
to
<link rel="stylesheet" href="../css/css.css">
This will find the css file from those files which are one level deeper in the pages folder.
Cannot link html/css pages
Change
<link rel="stylesheet" href="./css/css.css">
to
<link rel="stylesheet" href="../css/css.css">
This will find the css file from those files which are one level deeper in the pages folder.