feat: warn, if connection to server is lost

client/src/pages/play.vue

@@ -15,6 +15,10 @@
           <Final v-if="gameState === 'final'" />
         </div>
       </div>
+      <div v-if="connectionLost" class="page-play__error-box">
+        <div>connection to server lost</div>
+        <button @click="reload">reload</button>
+      </div>
       <div v-if="showDebugPanel" class="page-play__container-debug">
         <EngineDebug />
       </div>
@@ -40,6 +44,14 @@ export default {
     gamePhase() {
       return this.$store.state.game.phase
     },
+    connectionLost() {
+      return this.$store.state.engine.version == -1
+    },
+  },
+  methods: {
+    reload() {
+      window.location.reload()
+    },
   },
 }
 </script>
@@ -80,5 +92,21 @@ export default {
     font-size: 24px;
     color: #ffffff;
   }
+  &__error-box {
+    position: absolute;
+    left: 30%;
+    top: 10%;
+    width: 40%;
+    height: 5em;
+    padding: 1em;
+    border: 1px solid #ffffff;
+    border-radius: 20px;
+    background-color: #804040;
+    color: #ffffff;
+    text-align: center;
+    button {
+      margin: 1em;
+    }
+  }
 }
 </style>