Dear Leo,
Many thanks for your professional advice. I finally find the .container class is declared by the Toolset plugins and the problem is solved by deactivating the plugins in a sequence of type-access > wp-views > types > cred-frontend-editor > layouts, or I add the
body.home .container {
padding-left: 0px;
padding-right: 0px;
}
Hope this information can help other customers who use the GeneratePress and Toolset like me.
Best regards,
Kelvin.