Simple modification
Corresponds to the left and right
to vBulletin 5.6.4
Code:
.bbcode_container .bbcode_quote {
background: {vb:stylevar bbcode_quote_background};
font-size: 13px;
font-style: italic;
padding: 20px;
padding-right: 38px;
position: relative;
margin-bottom: 15px;
border: 2px solid #ddd;
border-radius: 8px;
padding-left: 38px;
-webkit-border-radius: 8px;
-moz-border-radius: 8px;
border-left: 3px solid #8CC8FF;
}