Error on CSS file?`

I want to change the custom icon that are in the landing i,e the fa-icon
so i create one css in the erpnext/erpnext/public/css/changes.css
also include this css into the file, also i added the icon in the public/images/icon.png here.but i am not able to see the icon in my landing page so how to fix this .please suggest.

bench build

try this but not any changes