diff --git a/12/style.css b/12/style.css
index 4e6c6ea..9442af7 100644
--- a/12/style.css
+++ b/12/style.css
@@ -612,14 +612,17 @@ iframe.hidden {
 #TOC_icon:hover {
 color: fuchsia;
 cursor:pointer;
+filter: invert(1);
 }
 #clock_icon:hover {
 color: fuchsia;
 cursor:pointer;
+filter: invert(1);
 }
 #resources_icon:hover {
 color: fuchsia;
 cursor:pointer;
+filter: invert(1);
 }
 .link_05:hover {
 color: fuchsia;