Crumb and Crust

hi - 

i am a novice at sourdough baking. 

This Bread is 50% strong white flour and 50% spelt flour. 65% hydration. Bulk ferment for 6 hours at room temperature then overnight fridge proofing in the banneton for 12 hours before scoring and baking. Total baking time 40 mn ( 20mn with steam and 20 minutes without steam) . 

The taste turned out great and it is soft inside. 

I am posting the picture of the crumb and crust As I would like to get your views and feedback on it. I think it can turn better ( maybe bigger holes and thicker crust ) and would like to know what needs to be done to improve it 

thanks 

Naj