Styling location of ‘read more’ after it has been clicked…

I’m using the <--more--> tag on a regular basis, and I was wondering if it is possible to style the location of that tag in the complete page.

I’d like to place something like a small dotted or dashed line in that place, so that the reader knows instantly where in the page to continue reading.

(I’m using the ‘Less’ plugin to show the complete post after the more-link has been clicked)