Change terrain surface size

bin/style.less

@@ -1122,7 +1122,7 @@ input[type=checkbox] {
 		position: relative;
 	}
 	.surface-preview {
-		@size: 45px;
+		@size: 85px;
 		background-size: @size @size;
 		width: @size;
 		height: @size;