A stormy surface hides a glowing teal world below

4:5, do this for a day that baffled humans:    Poster field I(x,y) = { I_above  if y > B(x) ;  I_below  if y ≤ B(x) }   where B = the topic's boundary (R₁)  I_above: storm/visible world, cool‑dark grade, top light I_below: hidden world, teal/bioluminescent (topic) grade, light source = emblem glow rising (R₃/R₅) interface: crisp (foam/bubbles/soil/ice edge) ⇒ reads as cross‑section title: extruded 3D letterforms, material=title_mat, weathered, tilt; legible (R₂) type: micro (staccato, top corner) ≺ cta ≺ info (bottom) hierarchy (R₄) η   weathering, boundary foam/bubbles, wreck/comb/magma detail, particles HONEST ⟺ piecewise ∧ crisp ∧ payload_iconic ∧ title_material ∧ hierarchy ∧ two_zone_grade ∧ η    -- "no split" = B undefined (single field) ; "empty depths" = I_below ≈ ∅ ; "flat title" = no extrude/material