added left border for focus state of list while tabbing through

src/popup/less/components.less

@@ -246,6 +246,11 @@
             background-color: @list-item-hover;
         }
 
+        &:not(:hover):focus {
+            border-left: 5px solid @brand-primary;
+            padding-left: 5px;
+        }
+
         .leading-icon {
             font-size: 35px;
             float: left;
@@ -310,6 +315,10 @@
             .btn-list {
                 padding: 8px;
             }
+
+            &:not(:hover):focus {
+                padding-left: 5px;
+            }
         }
 
         input:not([type="checkbox"]), select, textarea {