Como utilizar Media Queries para sites Responsivos.

Erro na Linha: #42 :: require(./_cdn/widgets/share/share.wc.php): Failed to open stream: No such file or directory
/home3/cvwebdesignercom/public_html/themes/oficial/inc/blog_informacoes.php

Fatal error: Uncaught Error: Failed opening required './_cdn/widgets/share/share.wc.php' (include_path='.:/opt/cpanel/ea-php83/root/usr/share/pear') in /home3/cvwebdesignercom/public_html/themes/oficial/inc/blog_informacoes.php:42 Stack trace: #0 /home3/cvwebdesignercom/public_html/themes/oficial/blog.php(17): require() #1 /home3/cvwebdesignercom/public_html/index.php(309): require('/home3/cvwebdes...') #2 {main} thrown in /home3/cvwebdesignercom/public_html/themes/oficial/inc/blog_informacoes.php on line 42