is it a curved staircase? What is the highest point of the staircase? maybe you can do something like this image:

Hello there, You could use MS square sections to create an array of shutters which will conceal the entire area, look contemporary and would be helpful in ventilation too. You could continue the whole thing towards the end and carve a simple cut-out from the shutter using MS sections and only a pair of hinges attached to the wall where stairs begin. You could also achieve the same feat with CNC cut jaalis, expanded metal mesh, concrete louvers etc. There is a wide spectrum of options you could consider depending on your budget. Regards, Aurum Ideas and Spaces Bhubaneswar

You can go for thread and riser tiles offered specially by Johnson co...

Just leave it as it is apply a layer of matte varnish over the concrete ...if needed just add a plank of leather finished granite over the tread