The receiver stands where the serve can actually go

The trick: hard serve, slight slide, and the first ten opponents died where
they stood. Measured headless — that serve was returned 0 times out of 24 at
EVERY rung. Three things were wrong and all three were the same thing: he
waited on the tennis mark 1.3 m off the centre line (covering the T, conceding
the whole corner), he took no first step, and he chased the ball's LIVE
position, which during a serve is still up by the server's baseline.

Now: he waits on the bisector of the serves he has to cover, takes a
returner's first step (serve-scoped — the rally is untouched), and runs at the
bounce instead of at the ball. The slid serve comes back from rung one; a
flush serve into the very corner of the box still aces the bottom of the
ladder, which is the reward placement is supposed to earn.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

src/render.js

@@ -85,7 +85,7 @@ function measureSafe(scale) {
   // BLOOD panel both sit 6 logical px in from the top-right); the DOM chips on top of it are laid
   // out in CSS px — and on a phone one logical px is ~1.4 CSS px, so the same "6" put the quit
   // chip a visible notch above the panels it is meant to line up with. One variable, one grid.
-  document.documentElement.style.setProperty('--hud', 6 * scale + 'px');
+  document.documentElement?.style.setProperty('--hud', 6 * scale + 'px'); // ?. — the headless suite has no root element
 }
 
 // The page background behind the canvas. It shows in exactly two places: the strip above the canvas