I had a website that's been down for over a month with 503 error. Will I recover my rankings?

I overlooked the fact that one of my websites has been offline for a month. Although I haven't been actively updating it, I have put in a significant amount of work on this domain over the past decade. It has accumulated over 20,000 backlinks. However, during this downtime, I have experienced an 80% drop in the keywords I used to rank for. Will these keywords recover, or am I in trouble?

Recovery is possible. By restoring service, updating content, and optimizing technical SEO, you can gradually regain your lost keywords over the coming months.