.whatsapp-btn {
         position: fixed;
         bottom: 40px;
         left: 20px;
         background-color: #25D366;
         color: white;
         padding: 12px 18px;
         border-radius: 50px;
         text-decoration: none;
         font-weight: 600;
         box-shadow: 0 4px 10px rgba(0,0,0,0.2);
         z-index: 999;
      }
      .whatsapp-btn:hover {
         background-color: #1ebe5d;
      }