XF 2.1 (Solved) How do I remove this gap between messages in mobile view?

[gogo]

I'm inspected the code but failed to find out which element it belongs to.

 

[gogo]

I finally found it.

@media (max-width: @xf-responsiveMedium) {
    .block--messages .message+.message
     {
        margin-top: 0px;
     }
}