diff --git a/main.lua b/main.lua
index 007b24a..37eecf2 100644
--- a/main.lua
+++ b/main.lua
@@ -626,8 +626,10 @@ JCA._wrap_text = wrap_text
 local ROW_BUDGET_MIN = 24
 local ROW_BUDGET_MAX = 60
 -- The card's OWN description popup sits between our tooltip and the card, eating
--- into the gutter. Approximate in game units; dbg() logs the inputs so it can be
--- tuned against a real hover.
+-- into the gutter. A joker's desc box is ~3.1-3.3 units wide; we subtract 4.6 so
+-- the budget always UNDER-estimates the true capacity -- with the smoke-measured
+-- metric (roomw 20, ~0.137 units/char at scale 0.32) that margin keeps every
+-- card, even one right at the 40% flip, clear of the edge. dbg() logs the inputs.
 local MAIN_BOX_UNITS = 4.6
 
 -- Width of one average character in room units at a text scale, from the game's