diff --git a/index.html b/index.html
index 421176252..69b33b6b0 100644
--- a/index.html
+++ b/index.html
@@ -10,6 +10,42 @@
     <script async="" defer="" src="https://buttons.github.io/buttons.js"></script>
   </head>
   <body>
+    <a href="https://github.com/atomiks/30-seconds-of-css" class="github-corner" aria-label="View source on Github">
+      <svg width="80" height="80" viewBox="0 0 250 250" style="fill:#151513; color:#fff; position: absolute; top: 0; border: 0; right: 0;" aria-hidden="true">
+        <path d="M0,0 L115,115 L130,115 L142,142 L250,250 L250,0 Z"></path>
+        <path d="M128.3,109.0 C113.8,99.7 119.0,89.6 119.0,89.6 C122.0,82.7 120.5,78.6 120.5,78.6 C119.2,72.0 123.4,76.3 123.4,76.3 C127.3,80.9 125.5,87.3 125.5,87.3 C122.9,97.6 130.6,101.9 134.4,103.2" fill="currentColor" style="transform-origin: 130px 106px;"
+          class="octo-arm"></path>
+        <path d="M115.0,115.0 C114.9,115.1 118.7,116.5 119.8,115.4 L133.7,101.6 C136.9,99.2 139.9,98.4 142.2,98.6 C133.8,88.0 127.5,74.4 143.8,58.0 C148.5,53.4 154.0,51.2 159.7,51.0 C160.3,49.4 163.2,43.6 171.4,40.1 C171.4,40.1 176.1,42.5 178.8,56.2 C183.1,58.6 187.2,61.8 190.9,65.4 C194.5,69.0 197.7,73.2 200.1,77.6 C213.8,80.2 216.3,84.9 216.3,84.9 C212.7,93.1 206.9,96.0 205.4,96.6 C205.1,102.4 203.0,107.8 198.3,112.5 C181.9,128.9 168.3,122.5 157.7,114.1 C157.9,116.9 156.7,120.9 152.7,124.9 L141.0,136.5 C139.8,137.7 141.6,141.9 141.8,141.8 Z"
+          fill="currentColor" class="octo-body"></path>
+      </svg>
+    </a>
+    <style>
+      .github-corner:hover .octo-arm {
+        animation: octocat-wave 560ms ease-in-out
+      }
+      @keyframes octocat-wave {
+        0%,
+        100% {
+          transform: rotate(0)
+        }
+        20%,
+        60% {
+          transform: rotate(-25deg)
+        }
+        40%,
+        80% {
+          transform: rotate(10deg)
+        }
+      }
+      @media (max-width:500px) {
+        .github-corner:hover .octo-arm {
+          animation: none
+        }
+        .github-corner .octo-arm {
+          animation: octocat-wave 560ms ease-in-out
+        }
+      }
+    </style>
     <button class="back-to-top-button" aria-label="back to top">↑</button>
     <nav class="sidebar" aria-label="Table of Contents">
       <button class="hamburger hamburger--spin sidebar__menu" type="button" aria-label="Menu" aria-expanded="false">
diff --git a/src/html/index.html b/src/html/index.html
index 10b35a213..f8669c4bd 100644
--- a/src/html/index.html
+++ b/src/html/index.html
@@ -10,6 +10,7 @@
     <script async="" defer="" src="https://buttons.github.io/buttons.js"></script>
   </head>
   <body>
+      <a href="https://github.com/atomiks/30-seconds-of-css" class="github-corner" aria-label="View source on Github"><svg width="80" height="80" viewBox="0 0 250 250" style="fill:#151513; color:#fff; position: absolute; top: 0; border: 0; right: 0;" aria-hidden="true"><path d="M0,0 L115,115 L130,115 L142,142 L250,250 L250,0 Z"></path><path d="M128.3,109.0 C113.8,99.7 119.0,89.6 119.0,89.6 C122.0,82.7 120.5,78.6 120.5,78.6 C119.2,72.0 123.4,76.3 123.4,76.3 C127.3,80.9 125.5,87.3 125.5,87.3 C122.9,97.6 130.6,101.9 134.4,103.2" fill="currentColor" style="transform-origin: 130px 106px;" class="octo-arm"></path><path d="M115.0,115.0 C114.9,115.1 118.7,116.5 119.8,115.4 L133.7,101.6 C136.9,99.2 139.9,98.4 142.2,98.6 C133.8,88.0 127.5,74.4 143.8,58.0 C148.5,53.4 154.0,51.2 159.7,51.0 C160.3,49.4 163.2,43.6 171.4,40.1 C171.4,40.1 176.1,42.5 178.8,56.2 C183.1,58.6 187.2,61.8 190.9,65.4 C194.5,69.0 197.7,73.2 200.1,77.6 C213.8,80.2 216.3,84.9 216.3,84.9 C212.7,93.1 206.9,96.0 205.4,96.6 C205.1,102.4 203.0,107.8 198.3,112.5 C181.9,128.9 168.3,122.5 157.7,114.1 C157.9,116.9 156.7,120.9 152.7,124.9 L141.0,136.5 C139.8,137.7 141.6,141.9 141.8,141.8 Z" fill="currentColor" class="octo-body"></path></svg></a><style>.github-corner:hover .octo-arm{animation:octocat-wave 560ms ease-in-out}@keyframes octocat-wave{0%,100%{transform:rotate(0)}20%,60%{transform:rotate(-25deg)}40%,80%{transform:rotate(10deg)}}@media (max-width:500px){.github-corner:hover .octo-arm{animation:none}.github-corner .octo-arm{animation:octocat-wave 560ms ease-in-out}}</style>
     <div class="content-wrapper"></div>
   </body>
 </html>
