Theme rework: polish dark mode and previews

Refine mobile nav layout, improve dark theme UI polish, and update README previews with light/dark variants.

public/index.html

@@ -4,6 +4,7 @@
   <meta charset="UTF-8">
   <meta name="viewport" content="width=device-width, initial-scale=1.0">
   <title>Pool Oscars</title>
+  <script src="./js/app_theme.js"></script>
   <link href="https://cdn.jsdelivr.net/npm/[email protected]/dist/css/bootstrap.min.css" rel="stylesheet">
   <link href="./css/app.css" rel="stylesheet">
   <style>
@@ -23,11 +24,32 @@
   </style>
 </head>
 <body class="bg-light">
+<button class="theme-toggle theme-toggle--floating" type="button" data-theme-toggle role="switch" aria-checked="false" aria-label="Basculer le mode sombre">
+  <span class="theme-toggle-icon theme-toggle-icon-sun" aria-hidden="true">
+    <svg viewBox="0 0 24 24" width="16" height="16" fill="none" stroke="currentColor" stroke-width="1.8" stroke-linecap="round" stroke-linejoin="round">
+      <circle cx="12" cy="12" r="4"></circle>
+      <path d="M12 2v2"></path>
+      <path d="M12 20v2"></path>
+      <path d="M4.93 4.93l1.41 1.41"></path>
+      <path d="M17.66 17.66l1.41 1.41"></path>
+      <path d="M2 12h2"></path>
+      <path d="M20 12h2"></path>
+      <path d="M4.93 19.07l1.41-1.41"></path>
+      <path d="M17.66 6.34l1.41-1.41"></path>
+    </svg>
+  </span>
+  <span class="theme-toggle-thumb" aria-hidden="true"></span>
+  <span class="theme-toggle-icon theme-toggle-icon-moon" aria-hidden="true">
+    <svg viewBox="0 0 24 24" width="16" height="16" fill="none" stroke="currentColor" stroke-width="1.8" stroke-linecap="round" stroke-linejoin="round">
+      <path d="M21 12.8A9 9 0 1 1 11.2 3a7 7 0 0 0 9.8 9.8z"></path>
+    </svg>
+  </span>
+</button>
 
 <div class="container">
   <div class="card p-4" style="max-width: 400px; margin: auto;">
     <div class="text-center mb-4">
-      <img src="img/logo.png" style="width: 80%;">
+      <img src="img/logo.png" class="logo-invert" style="width: 80%;" alt="Pool Oscars">
     </div>
     <form id="login-form">
       <div class="mb-3">
@@ -43,18 +65,10 @@
     <p class="mt-3 text-center">Pas de compte? <a href="/register.html">Enregistrez-vous</a></p>
   </div>
 
-  <!-- Footer Section  -->
-  <footer>
-    
-    <p id="footer-copy"><a id="copy" href="https://github.com/quoije/oscars-pool">quoije</a></p>
-    <p id="footer-text"></p>
-  </footer>
- 
 </div>
 
 <script src="https://cdn.jsdelivr.net/npm/[email protected]/dist/js/bootstrap.bundle.min.js"></script>
 <script src="./js/app_index.js"></script>
-<script src="./js/app_version.js"></script>
 
 </body>
 </html>