fade away resolved error messages on questions

app/assets/stylesheets/molecules/_forms.scss

@@ -266,6 +266,13 @@ select {
   margin-top: 2rem;
 }
 
+.resolve-error {
+  animation-name: success-fadeout;
+  animation-duration: 1.5s;
+  animation-delay: 0;
+  animation-fill-mode: forwards;
+}
+
 html.no-js {
   .chars {
     display: none;