diff --git a/_stylesheets/materials.css b/_stylesheets/materials.css
index c3fc12eff..3dd1dc66c 100644
--- a/_stylesheets/materials.css
+++ b/_stylesheets/materials.css
@@ -179,7 +179,7 @@ section {
       font-size: 80%; }
   .tab-panel .panel-content {
     width: 200%;
-    opacity: 0;
+    visibility: hidden;
     position: absolute;
     left: -50%;
     -webkit-transition: opacity 400ms;
@@ -206,7 +206,7 @@ section {
         color: #fff;
         opacity: 1; }
     .tab-panel input.material-type:checked + label.tab > div.panel-content {
-      opacity: 1; }
+      visibility: visible; }
 
 footer {
   float: left;
diff --git a/_stylesheets/materials.scss b/_stylesheets/materials.scss
index 8302264e7..0eebc39e5 100644
--- a/_stylesheets/materials.scss
+++ b/_stylesheets/materials.scss
@@ -221,8 +221,8 @@ section{
 
 	.panel-content{
 		width: 200%;
-		// visibility: hidden;
-		opacity: 0;
+		visibility: hidden;
+		// opacity: 0;
 		position: absolute;
 		left: -50%;
 
@@ -262,8 +262,8 @@ section{
 		}
 
 		&:checked + label.tab > div.panel-content{
-			// visibility: visible;
-			opacity: 1;
+			visibility: visible;
+			// opacity: 1;
 		}
 	}
 }