Fixing how styles are added to SVG documents to please IE

This also allowed the SVG element to be created in a single place

src/sass/main.scss

@@ -264,12 +264,17 @@ header {
           margin-left: -24px;
         }
 
-        svg {
+        .svg {
           position: absolute;
           top: -10000px;
         }
       }
 
+      .svg {
+        margin: 0;
+        text-align: center;
+      }
+
       figcaption {
         @include adjust-font-size-to($base-font-size);
         background: $green;