self-host fonts; proper error bubbling

src/Editor.css

@@ -1,14 +1,18 @@
 .editor {
+  padding: 2px;;
+}
+.editor.error {
+  border: 1px solid red;
+  display: inline-block;
+}
 
+.offending .error {
+  background-color: transparent;
 }
 
 .typeSignature {
   display: inline-block;
-  /* display: none; */
-  /* position: absolute; */
   z-index: 1;
-  /* background-color: white; */
-  /* border: 1px solid black; */
 }
 
 .editor:hover > .typeSignature {
@@ -23,9 +27,4 @@
 .keyword {
   color: blue;
   font-weight: bold;
-  /* vertical-align: top; */
-}
-
-* {
-  /* vertical-align: top; */
 }