Template:Quote/styles.css

 .mw-body blockquote {
   border-left: 4px solid #eaecf0;
   padding: 8px 32px
 }

 .mw-body blockquote> :first-child {
   margin-top: 0
 }

 .mw-body blockquote> :last-child {
   margin-bottom: 0
 }

 blockquote {
   border-left: 2px solid #000000;
   padding-left: 20px
 }