Size the YES canvas from its container, not window.innerHeight

The rasterized "YES" text (and everything downstream: fontSize, line
rendering) was recomputed from window.innerWidth/innerHeight on every
`resize` event. Mobile Safari fires `resize` continuously as the
address bar hides/shows while scrolling, so the text visibly rescaled
mid-scroll even after .hero-yes's own height was already stabilized
via 100svh. Reading the containing .hero-canvas box's own rendered
size instead ties canvas sizing to that already-stable CSS layout, so
a toolbar-only resize recomputes to the same numbers.

yes.js

@@ -58,8 +58,17 @@ export class RasterizedYES {
 
     setupCanvas() {
         const pixelRatio = window.devicePixelRatio || 1;
-        const width = window.innerWidth;
+        // Sized from the containing .hero-canvas box (CSS-driven by
-        const height = window.innerHeight;
+        // .hero-yes's 100svh), not window.innerWidth/innerHeight
+        // directly - mobile Safari fires `resize` continuously as the
+        // address bar hides/shows while scrolling, and innerHeight
+        // tracks that dynamic viewport. Reading the container's own
+        // rendered size instead means a toolbar-only resize recomputes
+        // to the same stable numbers (a no-op redraw) instead of
+        // visibly rescaling the rasterized "YES" text mid-scroll.
+        const rect = this.rasterCanvas.parentElement.getBoundingClientRect();
+        const width = rect.width;
+        const height = rect.height;
 
         this.rasterCanvas.style.width = width + 'px';
         this.rasterCanvas.style.height = height + 'px';