Handle deleted channels in sender

web/static/css/style.css

@@ -758,6 +758,16 @@ div.reminderError .errorHead .reminderTime {
     border-style: solid;
 }
 
+div.reminderError .reminderMessage {
+    font-size: 1rem;
+    display: flex;
+    flex-direction: column;
+    justify-content: center;
+    color: rgb(54, 54, 54);
+    flex-grow: 1;
+    font-style: italic;
+}
+
 /* other stuff */
 
 .half-rem {