Use the adverb congruently when two things easily fit together or exist side-by-side. If you and your college roommate live congruently, you're a perfect match with similar schedules and musical taste!
Congruently is from congruent and its Latin root congruere, "to agree or correspond with," or literally "to fit together." In math, the word describes geometric shapes that fit or match. Figuratively, things or people exist congruently when they're well-suited to each other: "My job at the nonprofit organization allows me to live congruently with my passion for fighting poverty."