Limit the maximum width to 100 characters.

To make reading on wide screens easier.

index.html

@@ -5,6 +5,10 @@
     <meta charset="utf-8">
     <meta name="robots" content="noindex, nofollow">
     <style>
+      body
+      {
+        max-width: 100ch;
+      }
       label
       {
         display: block;