diff --git a/themes/learn2-dark/css/custom.css b/themes/learn2-dark/css/custom.css
index cc0139b..ff2c3ad 100644
--- a/themes/learn2-dark/css/custom.css
+++ b/themes/learn2-dark/css/custom.css
@@ -60,7 +60,7 @@ code {
     */
 }
 .copy-to-clipboard:hover {
-  background-color: #333333;
+  background-color: #333333 !important; /* overwrite prism.css */
 }
 
 /* Sidebar currently selected main topic */
@@ -102,5 +102,5 @@ blockquote {
 
 /* disable "copy"-button on hover */
 div.code-toolbar:hover > .toolbar {
-  opacity: 0;
+  opacity: 0 !important; /* overwrite prism.css */
 }