design: add hardware acceleration offsets to border-beam to prevent corner jitter

vibn-frontend/app/(marketing)/new-site.tsx

@@ -1010,6 +1010,10 @@ function Hero({ onStart, variant = "quote" }) {
           offset-path: rect(0 auto auto 0 round var(--r-xl));
           offset-distance: 0%;
           offset-anchor: 50% 50%;
+          /* Force GPU hardware acceleration to remove subpixel snapping
+             and corner jitter */
+          will-change: transform, offset-distance;
+          transform: translate3d(0, 0, 0);
           background: linear-gradient(
             90deg,
             transparent,