Update css for terrain

bin/style.css

@@ -1008,15 +1008,15 @@ input[type=checkbox]:checked:after {
   position: relative;
 }
 .terrain-surfaces .surface-preview {
-  background-size: 45px 45px;
-  width: 45px;
-  height: 45px;
+  background-size: 85px 85px;
+  width: 85px;
+  height: 85px;
   outline: 4px solid #4a4a4a;
 }
 .terrain-surfaces .surface-preview-selected {
-  background-size: 45px 45px;
-  width: 45px;
-  height: 45px;
+  background-size: 85px 85px;
+  width: 85px;
+  height: 85px;
   outline: 4px solid #5897fb;
 }
 .terrain-surfaces .tooltiptext {

bin/style.less

@@ -1129,7 +1129,7 @@ input[type=checkbox] {
 		outline: 4px solid #4a4a4a;
 	}
 	.surface-preview-selected {
-		@size: 45px;
+		@size: 85px;
 		background-size: @size @size;
 		width: @size;
 		height: @size;