Divider line on search page

Hi All,

I would like to have a divider line between each result on the search page like you can see here: https://www.arbolife.com/en/stores/health-food/?sort_by=rating_count_desc

I did this initally by inserting a <hr> tag in the listing-listview.php with the following code: <hr class=”mydivider”> and css:

hr.mydivider {
  border: 0;
  height: 1px;
  background-image: -webkit-linear-gradient(left, #f0f0f0, #8c8b8b, #f0f0f0);
  background-image: -moz-linear-gradient(left, #f0f0f0, #8c8b8b, #f0f0f0);
  background-image: -ms-linear-gradient(left, #f0f0f0, #8c8b8b, #f0f0f0);
  background-image: -o-linear-gradient(left, #f0f0f0, #8c8b8b, #f0f0f0);
}

However, I noticed know this only works for the list view, but doesnt work when changing the view selection to grid mode (see screenshot).

How could I amend the code properly to include the HR tag so that its shown only when the list view is selected?

Many thanks
David