I can certainly do that, but do you know a way to do it via code? Web App Builder is simply where the app is starting it's life. We have various code modifications once we've done the initial work in WAB and could easily hit the pop-up customization as well. I should have mentioned that we're using the web app builder developer edition to create the apps and then we serve them off of our ArcGIS Server so we have access to all of the code files.
Yes I have run the developer tools before. Some projects have worked better than others but I suspect that is my lack of knowledge rather than the tools themselves. I will do as you suggest and let you know if I run into trouble. I have another question that may have a similar answer. Is it possible to move the pop-up window or change the leader length? I can branch this into a new discussion if that would be more appropriate.
You could use top and left, to position the pop-up, but if there is no container, it will move it based on the entire web page. Sounds like you just want to move it a little further away, so I would add a container around the popup and then set the top and left position in then and make sure you have the pop-up set to absolute. That's a guess, but worth a try.
You could also take a look at the pop-up's positioning and move it as it may already be defined on position within a container already. If it is, that will make it easy, just change the numbers, probably top and left until they are where you want them to be. I am not sure what leader length is, but CSS does have a length property. As long as it is unique ID, you can change it in CSS. So I would go about finding the leader ID and search for the length; it could be set to auto, but you can change it pixels or px in CSS.
I'll look for that as well. Thanks for the great information and I'll let you know how it goes. I don't think I'll be able to play with it until Thursday so don't think I'm ignoring you if I don't reply till next week.