Hi Tamer,

Not sure if I understand correctly your question but do you mean want to customise the css styling for responsive view in EasySocial? If yes, you can place your css code at 'JOOMLA/templates/[YOUR JOOMLA TEMPLATE]/html/com_easysocial/css/custom.css'. If the path is not exists in your Joomla template, you can create the folders structure and add custom.css into css folder.

Hope this help.