updated blog theme to default to left aligned images. To center images, use classname "center"

.themes/classic/sass/partials/_blog.scss

@@ -51,14 +51,15 @@ article {
     @include box-shadow(rgba(#000, .15) 0 1px 4px);
     @include box-sizing(border-box);
     display: block;
-    margin: 0 auto 1.5em;
   }
   img {
     &.left { float: left; margin-right: 1.5em; }
     &.right { float: right; margin-left: 1.5em; }
+    &.center { margin: 0 auto 1.5em; }
     &.left, &.right { margin-bottom: .8em; }
   }
-  video { display: block; margin-bottom: 1.5em; width: 100%; }
+  video, .flash-video { margin: 0 auto 1.5em; }
+  video { display: block; width: 100%; }
   .flash-video {
     > div {
       position: relative;