userstyle.css for Flowdock (~/Library/Application Support/Flowdock/userstyle.css)

userstyle.css

@media screen {
 * { 
     font-family: "Helvetica Neue";
     font-weight: 500;
 }
 
 #inbox * {
     font-family: "Helvetica Neue";
     font-size: 9pt;
     line-height:12pt;
     font-weight: 400;
 }
 
/*   #inbox > .message-list > .message {
     padding: 10px 16px 10px 16px !important;
   }
   
   #inbox > .message-list > .message .comment-count {
     left: 42px !important;
   }
   
   #inbox > .message-list > .message .type-icon {
     width: 16px !important;
     height: 12px !important;
   }
   
   #inbox > .message-list > .message .avatar {
     width: 40px !important;
     height: 40px !important;
     margin: 0 16px 0 0 !important;
   }
*/   
}