Separated citation style from the general blockquote style. The general blockquote style is great for nesting and indentation, while the citation is excellent for quote attribution.

.themes/classic/sass/base/_typography.scss

@@ -98,11 +98,15 @@ big { font-size: 1.2em; }
 
 blockquote { 
   $bq-margin: 1.2em;
+  padding-left: 1em;  
+}
+
+blockquote.citation {
+
   font-style: italic;
   position: relative;
   font-size: 1.2em;
   line-height: 1.5em; 
-  padding-left: 1em;
   border-left: 4px solid rgba($text-color-light, .5);
   cite {
     font-style: italic;