fixes and functions

static/js/url-state.js

@@ -10,10 +10,15 @@
 const VIEWS = new Set(["edit", "split", "preview"]);
 const MODES = new Set(["markdown", "text"]);
 
+function defaultEditorView() {
+  return window.matchMedia("(max-width: 760px)").matches ? "edit" : "split";
+}
+
 export function readEditorState() {
   const params = new URLSearchParams(window.location.search);
+  const requestedView = params.get("view");
   return {
-    view: VIEWS.has(params.get("view")) ? params.get("view") : "split",
+    view: VIEWS.has(requestedView) ? requestedView : defaultEditorView(),
     mode: MODES.has(params.get("mode")) ? params.get("mode") : "markdown",
   };
 }