title: Where should I put my css files?
body: <p>I have a middle size of website that share a common header/footer and almost each page would have its own specific file for layout. I have put the common header/footer in a sperated html file, but I do not know where to put the css file because the link element in  footer.html  <code>&lt;link rel="stylesheet" type="text/css" href="footer.css" /&gt;</code> will not link to the current directory of this html file but the requiring php file. </p>
  
  <p>I look around quite a few websites and definitively there is no uniform solution. One solution is put all the css file in <code>root-directory/css</code>, while quite a few websites use hierarchical directory like <code>'/skin' '/global'</code> etc. The others choose a quite differential way using links like <code>http://sstatic.net/stackoverflow/all.css?v=5fc0e3026fcc</code> (this is the stackoverflow way).</p>
  
  <p>So my question which way is better or should I use for my situation?</p>
  
  <p>ps. actually I think this problem could also apply to image file storage. </p>