edx.org: ensures that the iframe-based register button has a transparent background

lms/static/sass/_shame.scss

@@ -131,6 +131,7 @@
 
 // edx.org marketing site - registration iframe band-aid (poor form enough to isolate out)
 .view-iframe, .view-iframe-content {
+  background: transparent !important;
   overflow: hidden;
 }