add subtle glow to CalendarDoor numbers

ui/src/components/calendar/CalendarDoor.vue

@@ -4,10 +4,30 @@
     :visible="store.is_touch_device || force_visible"
     :rectangle="door.position"
   >
-    <div class="has-text-danger">{{ door.day }}</div>
+    <div class="has-text-danger glow">{{ door.day }}</div>
   </SVGRect>
 </template>
 
+<style lang="scss" scoped>
+@import "@/bulma-scheme";
+
+.glow {
+  -webkit-animation: glow 2s ease-in-out infinite alternate;
+  -moz-animation: glow 2s ease-in-out infinite alternate;
+  animation: glow 2s ease-in-out infinite alternate;
+}
+
+@keyframes glow {
+  from {
+    text-shadow: 0 0 10px white, 0 0 20px white, 0 0 30px $primary,
+      0 0 40px $primary, 0 0 50px $primary, 0 0 60px $primary, 0 0 70px $primary;
+  }
+  to {
+    text-shadow: 0 0 10px white;
+  }
+}
+</style>
+
 <script lang="ts">
 import { Door } from "@/lib/door";
 import { advent22Store } from "@/plugins/store";