better selectors for category-item and topic-item

less/style.less

@@ -123,7 +123,7 @@ a:hover, .btn-link:hover, .btn-link:active, .btn-link:focus {
 }
 
 
-.post-row .topic-item, #topics-container .category-item {
+.topic .topic-item, .category .category-item {
 	-webkit-transition: background-color 500ms linear;
 	-moz-transition: background-color 500ms linear;
 	-ms-transition: background-color 500ms linear;
@@ -131,7 +131,7 @@ a:hover, .btn-link:hover, .btn-link:active, .btn-link:focus {
 	transition: background-color 500ms linear;
 }
 
-.post-row .topic-item.highlight, #topics-container .category-item.highlight {
+.topic .topic-item.highlight, .category .category-item.highlight {
 	background-color: lighten(@brand-info, 20%);
 }