Use cookies for dark mode

(also reverts most back-end changes from previous commit)

resources/views/layouts/nav-buttons.blade.php

@@ -15,6 +15,19 @@ $aclass = $dropdown ? 'dropdown-item' : 'nav-link';
     <i class="fa-key-modern fa-pr"></i>{{ __('Settings') }}
   </a>
 
+{!! $li !!}
+  <form method="POST" action="{{ route('toggle-dark-mode') }}" aria-hidden="true">
+    @csrf
+    <button id="toggle-dark-mode-btn" class="{{ $aclass }}" type="submit" onclick="event.preventDefault(); toggleDarkMode();">
+        <div class="dark-mode-switch-on">
+            <i class="fa-sun-o fa-pr"></i>{{ __('Light Mode') }}
+        </div>
+        <div class="dark-mode-switch-off">
+            <i class="fa-moon-o fa-pr"></i>{{ __('Dark Mode') }}
+        </div>
+    </button>
+  </form>
+
 {!! $li !!}
 <a class="{{ $aclass }}" href="{{ route('logout') }}"
    onclick="event.preventDefault(); document.getElementById('logout-form').submit();">