Reading the chambers
Each square is one seat, and parties run left to right by ideology — French-hemicycle style, per the sim wiki — rather than by size. The dashed oxblood line marks where a majority is secured in each full chamber.
The Senate shows its full standing chamber, not just this cycle’s races: each state holds two seats on staggered four-year terms, so half the chamber is always mid-term. Chamber totals are the officially recorded compositions — a jump between cycles is new statehood (or secession), not an error.