Add background color to cockpit canvas

src/partials/thecockpit.html

@@ -6,7 +6,7 @@
       In Myrtle Beach South Carolina, Richard and Isaac counted 100 Chrysler Pacificas in the span of a week.
     </djot>
   </x-section-head>
-  <div id="cockpit-canvas" style="height: 80vh;  margin: 8px"></div>
+  <div id="cockpit-canvas" style="height: 80vh;  margin: 8px; background-color: #000;"></div>#000
 </x-tab.content>
 <script>
   var interval = setInterval(function () {