remove border from diagrams

build/templates/diagram.template

@@ -1,5 +1,5 @@
 <div class="threejs_diagram_container">
-  <iframe class="threejs_example {{className}}" style="width: {{width}}px; height: {{height}}px;" src="{{{examplePath}}}{{{url}}}"></iframe>
+  <iframe class="threejs_diagram {{className}}" style="width: {{width}}px; height: {{height}}px;" src="{{{examplePath}}}{{{url}}}"></iframe>
   {{#caption}}
   <div class="threejs_center">{{{../caption}}}</div>
   {{/caption}}

threejs/lessons/resources/lesson.css

@@ -228,11 +228,13 @@ iframe {
 iframe.body {
   height: 100vh;
 }
-iframe.threejs_example {
+iframe.threejs_example, iframe.threejs_diagram {
   border: none;
   margin-left: auto;
   margin-right: auto;
   display: block;
+}
+iframe.threejs_example {
   border: 1px solid black;
 }
 iframe.noborder {