diff --git a/static/index.html b/static/index.html
index feeb983..789df28 100644
--- a/static/index.html
+++ b/static/index.html
@@ -5,7 +5,7 @@
     <script type="text/javascript" src="script.js" defer></script>
   </head>
   <body>
-    Input org-mode source:<br/>
+    <h2>Input org-mode source:</h2>
     <textarea id="org-input" rows="24" cols="80"></textarea>
     <hr/>
     <div id="parse-output" class="code_block" style="padding-left: calc(2ch + 10px); counter-set: code_line_number 0;"><code>This is line 1</code><code class="highlighted">This is line 2</code><code>This is line 3</code></div>
diff --git a/static/script.js b/static/script.js
index 06b8c00..6c4478d 100644
--- a/static/script.js
+++ b/static/script.js
@@ -22,6 +22,7 @@ inputElement.addEventListener("input", async () => {
         inFlightRequest.abort();
         inFlightRequest = null;
     }
+    outputElement.innerHTML = "";
 
     let newRequest = abortableFetch("/parse", {
         method: "POST",
diff --git a/static/style.css b/static/style.css
index 3822e6a..db98321 100644
--- a/static/style.css
+++ b/static/style.css
@@ -1,3 +1,28 @@
+h1, h2, h3, h4, h5, h6, h7 {
+    font-weight: 700;
+}
+h1 {
+    font-size: 28px;
+}
+h2 {
+    font-size: 24px;
+}
+h3 {
+    font-size: 22px;
+}
+h4 {
+    font-size: 20px;
+}
+h5 {
+    font-size: 18px;
+}
+h6 {
+    font-size: 18px;
+}
+h7 {
+    font-size: 18px;
+}
+
 .code_block {
     font: 14px/1.4 "Cascadia Mono", monospace;
     background: #272822ff;
@@ -5,8 +30,6 @@
     display: table;
     white-space: break-spaces;
     padding: 5px;
-
-    /* color for line numbers  */
 }
 
 .code_block > code {
