I changed the footer.php file to customize my own footer, but I found that when I switched to the mobile view, the copyright section text will have a black underline which is not the property of the copyright. I don’t know how to remove this underline. Could you help me? Thanks
It looks like this is being inherited from the .site-footer element. In order to remove it, navigate to Customize > Advanced > Custom JS & CSS and paste the following rule into your Custom Theme CSS field: