tweak css to make links on front page work properly

src/_includes/styles.css

@@ -222,15 +222,18 @@ nav {
     transform: none;
   }
 
+  /* the commented out calcs work in firefox and mobile, but not in chromium */
   .link_tiles_grid>a,
   .link_tiles_grid>a>img {
     max-width: 230px;
-    width: calc((100vw - 100px)/3);
+    width: calc((100vw - 117px)/3);
+    /* width: calc((100vw - 100px)/3); */
   }
 
   .link_tiles_grid>a>img {
     max-height: 230px;
-    height: calc((100vw - 100px)/3);
+    height: calc((100vw - 117px)/3);
+    /* height: calc((100vw - 100px)/3); */
   }
 
   /* switch to two tiles when it gets really small */
@@ -238,11 +241,13 @@ nav {
 
     .link_tiles_grid>a,
     .link_tiles_grid>a>img {
-      width: calc((100vw - 85px)/2);
+      width: calc((100vw - 102px)/2);
+      /* width: calc((100vw - 85px)/2); */
     }
 
     .link_tiles_grid>a>img {
-      height: calc((100vw - 100px)/2);
+      height: calc((100vw - 117px)/2);
+      /* height: calc((100vw - 100px)/2); */
     }
   }
 }