Deleting padding for single responsive grid row flex-cell

I’ve been trying this for a while now, but can’t seem to figure out how to delete the padding for just a single flex-cell and not all of them.
I’ve assigned a specific css-class to the cell (“row_mobile”) but still can’t isolate it.
My current code looks like this:

.responsive #top #wrap_all .av-flex-cells .no_margin .row_mobile{
padding-left: 0px!important;
padding-right: 0px!important;
}

The forced padding originates from the grid.css and I haven’t found a way to overwrite it via Inline CSS yet.
Is there a way of doing this?