diff --git a/app/views/liquids/_speakerdeck.html.erb b/app/views/liquids/_speakerdeck.html.erb
index 3b521e298..18336e36b 100644
--- a/app/views/liquids/_speakerdeck.html.erb
+++ b/app/views/liquids/_speakerdeck.html.erb
@@ -1,9 +1,9 @@
+<%# Padding bottom set for 16:9 aspect ratio https://benmarshall.me/responsive-iframes/ %>
 <div class="ltag_speakerdeck"
   style="position: relative;
     width: 100%;
     height: 0;
-    padding-bottom: calc(57% + 58px);
-    margin-bottom:1em auto 1.3em; ">
+    padding-bottom: 56.25%;">
   <iframe allowfullscreen="true"
     allowtransparency="true"
     frameborder="0"