uodate problem rendered style

app.css

@@ -150,7 +150,21 @@
 }
 
 .problem-input-markdown {
-  padding: 8px;
+  padding-top: 18px;
   border: 1px solid rgba(0, 0, 0, 0.15);
   border-radius: 10px;
+  position: relative;
+  max-height: 380px;
+  overflow-y: auto;
+}
+
+.problem-input-markdown::before {
+  content: "Problem rendered";
+  border: 1px solid rgba(0, 0, 0, 0.15);
+  border-radius: 10px;
+  position: absolute;
+  left: 0;
+  top: 0;
+  border-right: 1px solid rgba(0, 0, 0, 0.15);
+  border-bottom: 1px solid rgba(0, 0, 0, 0.15);
 }