Blue screen of death when theres an error

main.css

@@ -145,6 +145,39 @@ body.iOS div.hint {
   visibility: visible;
 }
 
+#bsodmom {
+  position: absolute;
+  top: 0;
+  left: 0;
+  width: 100%;
+  height: 100%;
+  text-align: center;
+  vertical-align: middle;
+  display: none;
+}
+#bsod {
+  width: 500px;
+  background-color: #008;
+  color: white;
+  font-family: courier, monospace;
+  font-size: 14px;
+  margin: auto;
+  margin-top: 100px;
+  padding: 40px;
+}
+#bsod p {
+  text-align: left;
+  margin: 1em;
+}
+#bsod p.c {
+  text-align: center !IMPORTANT;
+}
+#bsod p.c span {
+  background: silver;
+  color: #008;
+}
+
+
 div#paused {
   display: none;
   position: absolute;