diff --git a/webpage/playground/index.html b/webpage/playground/index.html
index c3b9df3..6d49899 100644
--- a/webpage/playground/index.html
+++ b/webpage/playground/index.html
@@ -2,6 +2,8 @@
 <html>
 <head>
     <meta charset="utf-8">
+    <meta http-equiv="X-UA-Compatible" content="IE=edge">
+    <meta name="viewport" content="width=device-width, initial-scale=1">
     <title>apfl Playground</title>
     <style type="text/css">
         .apfl_playground {
@@ -26,6 +28,10 @@
             }
         }
 
+        html {
+            font-size: 16px;
+        }
+
         .apfl_playground {
           background: var(--bg);
           color: var(--fg);
