How to Remove Grey Line From Mobile ?

Hello Great Catch Team! Please take a look at this screenshot: https://www.dropbox.com/s/5h9uq8ono7zjrye/grey%20line.jpg?dl=0 How can i remove this grey line? This grey line is visible only on mobile not desktop, how to remove it? the line is visible only on excerpts and only on mobile. website: https://www.natureword.com/