Add pause styles to runner canvas

src/app/app.css

@@ -1612,6 +1612,10 @@ button:disabled {
   box-shadow: inset 0 0 0 9999px rgba(9, 38, 62, 0.08);
 }
 
+.runner-canvas--paused {
+  box-shadow: inset 0 0 0 9999px rgba(255, 255, 255, 0.03);
+}
+
 .runner-canvas__underwater {
   position: absolute;
   inset: 0;
@@ -1628,6 +1632,47 @@ button:disabled {
   mix-blend-mode: screen;
 }
 
+.runner-canvas__pause-veil {
+  position: absolute;
+  inset: 0;
+  z-index: 4;
+  pointer-events: none;
+  background:
+    radial-gradient(
+      circle at 50% 24%,
+      rgba(255, 255, 255, 0.22),
+      transparent 46%
+    ),
+    linear-gradient(
+      180deg,
+      rgba(255, 255, 255, 0.12),
+      rgba(244, 246, 250, 0.2)
+    );
+  backdrop-filter: blur(12px) saturate(0.72);
+}
+
+.runner-canvas__pause-title {
+  position: absolute;
+  top: 50%;
+  left: 50%;
+  z-index: 6;
+  color: #ffffff;
+  font-family:
+    "Iowan Old Style", "Palatino Linotype", "Book Antiqua", Georgia, serif;
+  font-size: clamp(3.4rem, 8vw, 6.8rem);
+  font-weight: 700;
+  letter-spacing: 0.1em;
+  line-height: 0.96;
+  text-transform: uppercase;
+  transform: translate(-50%, -56%);
+  pointer-events: none;
+  -webkit-text-stroke: 1.4px rgba(104, 109, 120, 0.72);
+  text-shadow:
+    0 0 1px rgba(104, 109, 120, 0.85),
+    0 2px 12px rgba(82, 88, 101, 0.28),
+    0 10px 28px rgba(255, 255, 255, 0.16);
+}
+
 .runner-canvas__prompt {
   position: absolute;
   left: 50%;