Update theme toggle mechanism

styleguide/assets/style/base.scss

@@ -208,18 +208,29 @@ $mobile-navigation-height: 4rem;
   @include theme_light();
 }
 
-html,
-html.light {
-  @include theme_light();
-}
-
-html.dark {
-  @include theme_dark();
-}
-
 @media (prefers-color-scheme: dark) {
   html {
     @include theme_dark();
+
+    &:has(#themeLight:checked) {
+      @include theme_light();
+    }
+  }
+  #themeToggleDark {
+    display: none;
+  }
+}
+
+@media (prefers-color-scheme: light) {
+  html {
+    @include theme_light();
+
+    &:has(#themeDark:checked) {
+      @include theme_dark();
+    }
+  }
+  #themeToggleLight {
+    display: none;
   }
 }