fix: hide the window hint while a sign is in flight

src/styles/gantry.css

@@ -322,6 +322,12 @@ html[data-gantry='docked'] .gantry-window {
   opacity: 1;
   translate: 50% 0;
 }
+/* While a sign is on its way the hint would name an exit the car is already
+   driving to, so it waits until the window is at rest again. */
+html:is([data-interlude], [data-gantry='incoming'], [data-gantry='passing']) .gantry-window .gantry-window__hint {
+  opacity: 0;
+  transition-duration: 80ms;
+}
 @media (max-width: 359px) {
   .gantry-window { display: none; }
 }