We are still within the speculative first second. The Electroweak Era ends around 10−12 seconds after the Big Bang. Following inflation, the universe continued to expand and cool, allowing the electromagnetic and weak nuclear forces to separate. Particles continued to form and annihilate in a hot, dense environment, but as the universe cooled further, the formation of more stable particles like protons and neutrons became possible.
A bit speculative. Grounded in well-established physical theories and supported by high-energy particle physics experiments that test conditions analogous to those of the early universe.