Hi there!

Thanks for your query. Which lines you are talking about, please? Can I have a screenshot indicating those lines?

However, the following code snippet will remove the lines under sppb addons:

.sppb-addon:after{
display:none;
}

And the below code will help you to remove the thin line under article header:

.view-article .entry-header h2 {
    border-bottom: none;
        }

You need to use the codes in your custom CSS.

Note: Path towards custom CSS: Extensions>Templates>Styles> Click on your current default template name then choose Template Options. Then find custom CSS within the custom code.

Hope this helps!

Best Regards