Sedov blast-wave test at t = 4 s. Each panel shows one hydrodynamic variable: density (ρ), velocity (v), pressure (p), and specific internal energy (U, log scale). Upper panels compare the analytical solution (black solid) to four numerical configurations: SNEC/SuperSNEC N = 100 on the static legacy grid (blue solid), SNEC/SuperSNEC N = 1000 on the legacy grid (orange solid), SuperSNEC N = 100 on the adaptive grid (green dashed), and SuperSNEC N = 1000 on the adaptive grid (red dashed). Lower subpanels show the fractional error δ = ∣(exact − numerical)/exact∣. The legacy-grid runs are labeled “SNEC/SuperSNEC” because both codes produce identical results to machine precision on the same grid. The analytical solution is computed from the J. R. Kamm & F. X. Timmes (2007) parametric solver. Setup: ρ₀ = 1 g cm⁻³, E₀ = 1 erg, γ = 1.4, no radiation or gravity.