You have a few options here. One would be to create a dot graphic, and then add it as a background image via the Background property group. You can positionthe dot using the background-position property. And set background-repeat to no-repeat.
Another option is create an ::after pseudo element. The advantage being that you don’t have to create the dot in a graphics program. The following video shows to to create a pseudo element selector for the dot and then position and style it:
Note: many of the CSS styles applied to the pseudo element in the video are necessary to make the pseudo element appear (e.g. setting the content property with empty ‘ ‘, width/height, and position:absolute).
Also, remember to turn off the ::after selector modifier when you next create a selector.