Pants
Initially hiked for years with a Fjallraven High Coast (via this link a newer model than I bought in 2020). Underneath, with less weather, Craft long underpants.
It is now 2024, thanks to the perfect personalized advice from the unparalleled Carl Denig, these pants. Underneath, based on the advice above, I chose a long Icebreaker thermal underwear. I also bought a short-sleeve and a long-sleeve shirt from the same brand, and that is, for now, the perfect setup!