Fix large screen carousel controls

Fixes #9031

src/assets/less/site/responsive/screen-lg.less

@@ -7,13 +7,13 @@
   }
 
   .carousel-control {
-    top: @size + 25px;
-    .square(30px);
+    top: @size + 35px;
+    .square(40px);
     font-size: 40px;
-    line-height: 35px;
-    left: 370/2 - 42px;
+    line-height: 40px;
+    left: 370/2 - 52px;
     &.right {
-      right: 370/2 - 42px;
+      right: 370/2 - 52px;
     }
   }