Make sure badge always defaults to @username

index.html

@@ -13,7 +13,7 @@
     <div class="container">
       <h1>⚡️ tippin.me Badge Generator</h1>
       <p class="description">Enter your Twitter username</p>
-      <input type="text" name="username">
+      <input type="text" name="username" placeholder="username" autofocus>
       <div class="badge-preview"></div>
     </div>
 

script.js

@@ -13,7 +13,8 @@ const username = document.querySelector('input[name="username"]');
 const badgePreview = document.querySelector('.badge-preview');
 
 const generateBadge = () => {
-  badgePreview.innerHTML = badgeHtml(escape(username.value));
+  badgePreview.innerHTML = badgeHtml(escape(username.value) || 'username');
 };
 
+generateBadge();
 username.addEventListener('input', generateBadge);