how do we access the image files from static resource in css=?iso-8859-1?Q?=3F_=96_salesforce.stackexchange.com?=

how do we access the image files from static resource in css? –
salesforce.stackexchange.com

I am trying to display images from a static resource in a css property.
.PDF { width:50px; height:50px; background-image:
url("{!URLFOR($Resource.FileTypes, 'png/pdf.png')}"; } What i …