Support touchscreen navigation.

src/partials/_nav_dropdown.scss

@@ -1,5 +1,5 @@
 .dropdown {
-    > header {
+    > label.item {
         display: grid;
         grid-template-columns: 1fr min-content;
         align-items: center;
@@ -20,10 +20,18 @@
         padding: 0 var(--spacing-small);
         list-style: none;
     }
+
+    > input:checked + label {
+        color: var(--highlight-hover);
+
+        + ul {
+            display: grid;
+        }
+    }
 }
 
 .dropdown:hover {
-    > header {
+    > label.item {
         transform: var(--transform-scale-x);
 
         > ion-icon {
@@ -38,7 +46,7 @@
 }
 
 @media only screen and (max-width: 500px) {
-    .dropdown > header > ion-icon {
+    .dropdown > label.item > ion-icon {
         margin-right: var(--padding-mobile);
     }
 }

src/partials/_pane_nav.scss

@@ -41,16 +41,14 @@ nav.pane {
         }
     }
 
-    nav.pane > #toggle:checked {
-        + .nav_header {
-            color: var(--highlight-hover);
+    nav.pane > input:checked + label {
+        color: var(--highlight-hover);
 
-            + .menu {
-                display: grid;
+        + .menu {
+            display: grid;
 
-                + .location + .quick_links {
-                    display: flex;
-                }
+            + .location + .quick_links {
+                display: flex;
             }
         }
     }