I am going to install a new handrail in the stairs. I have bought two posts that I will mount on the bottom stringer of the stairs. I will then attach the handrail to the posts. But now to my question. How do I mount the posts on the stringer in the best-looking way? Which screws/bolts should I use? The posts are 90x90 mm and the stringer is 30 mm wide. The posts should be placed where the blue markings are.