CSS and JS not appearing on my live website [closed]

hope you're doing great! Recently I finished working on my business website. But suddenly one strange problem appeared. I'm using Joomla CMS and Quix Page Builder to create my website. When I'm in editing mode, the website looks just fine:

https://i.stack.imgur.com/VDidV.png

But when you visit selltoinspire.com , a big chunk of the CSS and JS effects aren't appearing:

https://i.stack.imgur.com/5udat.png

I've tried to stop all my extensions, plugins and modules, but still, the problem remains. I've contacted a freelance developer and he told me that the problem is related to my page builder. But when I contacted the support team of Quix page builder, they haven't found the solution. That's why I decided to share that problem here.

Keep in mind that I'm not a developer, so I can't provide you with a detailed explanation. However, I have a grasp of basic website development, so if you need something specific from me to show you, just tell me. It's urgent for me to fix that website, so any help is appreciated.

Thank you all in advance!