diff --git a/docs/stylesheets/extra.css b/docs/stylesheets/extra.css
index 75ccaa5..e0eab1c 100644
--- a/docs/stylesheets/extra.css
+++ b/docs/stylesheets/extra.css
@@ -5,3 +5,42 @@ article .player {
 .ap-player .ap-overlay {
   z-index: 2;
 }
+
+span.email {
+  font-weight: bold;
+}
+
+span.email b {
+  display: none;
+}
+
+a.btn-gh-sponsors {
+  background-color: #eee;
+  border-color: #ccc;
+  color: #333;
+  font-weight: 600;
+  border-radius: .2rem;
+  font-size: 90%;
+  line-height: 1.5;
+  padding: .25rem .5rem;
+  display: inline-block;
+  text-align: center;
+  vertical-align: middle;
+  text-decoration: none;
+  box-sizing: border-box;
+}
+
+a.btn-gh-sponsors:hover {
+  color: #000;
+}
+
+a.bitcoin-logo {
+  vertical-align: middle;
+  line-height: 1.5em;
+}
+
+a.bitcoin-logo img {
+  margin-right: 10px;
+  width: 32px;
+  vertical-align: middle;
+}