Add back that login error thing that someone removed

src/App.scss

@@ -654,6 +654,33 @@ nav {
   border-radius: var(--inputRadius, $fallback--inputRadius);
 }
 
+@keyframes shakeError {
+  0% {
+    transform: translateX(0);
+  }
+  15% {
+    transform: translateX(0.375rem);
+  }
+  30% {
+    transform: translateX(-0.375rem);
+  }
+  45% {
+    transform: translateX(0.375rem);
+  }
+  60% {
+    transform: translateX(-0.375rem);
+  }
+  75% {
+    transform: translateX(0.375rem);
+  }
+  90% {
+    transform: translateX(-0.375rem);
+  }
+  100% {
+    transform: translateX(0);
+  }
+}
+
 @media all and (max-width: 959px) {
   .mobile-hidden {
     display: none;