Fix the cover image width to stay at or below 900px in width

site/static/css/theme.styl

@@ -317,7 +317,7 @@ article
   > .home-block > .photo
     position: relative
     left: -40px
-    width: 105%
+    width: 104.6%
     max-height: 180px
     margin: 0 0 2em 0
     overflow: hidden
@@ -342,7 +342,7 @@ article
   > .home-block > .video
     position: relative
     left: -40px
-    width: 105%
+    width: 104.6%
     max-height: 360px
     margin: 0 0 2em 0
     background: #000