First 1 Gallon Brew: Sierra Madre

I have a concern with my first one gallon brew. I did as the directions instructed. I started my boil at 1.25 gallon but it boiled under 1 gallon over the 45 minutes. I was at an OG of 1.78 at this point. Should I have topped off with water to the one gallon mark or left as is? Im still a new brewer as this was my third batch ever. This was a success though because I steeped grains and had three hops additions. Both were a first for me. If smell matters at all, this will be A wonderful batch. I’m concerned though with the boil off. Either way I’ll have beer for sure and will know what to expect next time which is more valuable.

Just add the water that is needed to bring it up to the gallon mark and mix it up well. Congrats on your first batch