Mixed content problem

Hello,

I spend long trying to find out where the mixed content is coming from.

First when the page load it says the page is secure, but after loading it say insecure, as far as i can see it is coming from some CSS.

Absolutely not, the problem is it loads content from your demo website on my website. That’s why there is mixed content . This makes my site slower also…

Please help me out.
Thanks.