First good sourdough loaf

So, I've been lurking around this forum a bit and decided to finally join.  I'm pretty new to this baking thing.  I've made 5 loaves now.  Two with my own sourdough starter, the first of which was a flop, too wet, too sticky, probably didn't rise long enough, etc etc.  But this morning I had my first good bake.  Here's what I did:

100g levain (50/25/25 water/whole wheat/white flour)
50g whole wheat flour
400g bread flour
337g water
9g salt

AKA :: 15% whole wheat, 77.4% hydration

Bulk rise at room temp (70*F) for 13hrs, with a few folds in the first 1.5hr
Shaped, and proofed in the refrigerator for 8hrs.
One last hour proofing on the counter this morning while the oven was coming up to temp.
Baked on a thick pizza stone w/a pot over top as a cover, aka a poor mans dutch oven haha

Baked at 475*F, 45mins covered, 15mins uncovered.

Super happy with how this one turned out. Cutting into it tonight when I go camping with some friends.

Certainly open to any tips, pointers, thoughts, etc.