diff --git a/css/step1.css b/css/step1.css
index 91e71a6..fd5be6f 100644
--- a/css/step1.css
+++ b/css/step1.css
@@ -484,7 +484,7 @@ footer[role="contentinfo"] {
     padding-top: 5.25em;
   }
   #nav:not(:target) {
-    z-index: 1;
+    z-index: -1;
     height: 0;
   }
   #nav:target .close-btn {
diff --git a/css/step2.css b/css/step2.css
index f17e41a..635e19a 100644
--- a/css/step2.css
+++ b/css/step2.css
@@ -484,7 +484,7 @@ footer[role="contentinfo"] {
     padding-top: 5.25em;
   }
   #nav:not(:target) {
-    z-index: 1;
+    z-index: -1;
     height: 0;
   }
   #nav:target .close-btn {
diff --git a/css/step3.css b/css/step3.css
index 845d463..827ccd8 100644
--- a/css/step3.css
+++ b/css/step3.css
@@ -484,7 +484,7 @@ footer[role="contentinfo"] {
     padding-top: 5.25em;
   }
   #nav:not(:target) {
-    z-index: 1;
+    z-index: -1;
     height: 0;
   }
   #nav:target .close-btn {
diff --git a/css/step4.css b/css/step4.css
index 844b7a7..3e12f72 100644
--- a/css/step4.css
+++ b/css/step4.css
@@ -484,7 +484,7 @@ footer[role="contentinfo"] {
     padding-top: 5.25em;
   }
   #nav:not(:target) {
-    z-index: 1;
+    z-index: -1;
     height: 0;
   }
   #nav:target .close-btn {