We are still within the speculative first second. Following inflation, the universe continued to expand and cool. During the Electroweak Era, the electromagnetic and weak nuclear forces still behaved as one electroweak force. As the universe cooled further, that unity broke: electromagnetism and the weak force separated into the distinct forces we know today.

This was still a hot, dense world of particles forming and annihilating almost instantly. Nothing like atoms existed yet. Even protons and neutrons were not stable structures at this point. But the stage was being set. As cooling continued, quarks would later bind together, making the formation of more stable particles possible.

A bit speculative. This era is grounded in well-established physical theories and supported by high-energy particle physics, including experiments that test pieces of the electroweak model and recreate conditions analogous to the early universe.