body {
    margin: 0;
    font-family: Arial, sans-serif;
  }
  
  /* WRAPPER */
  .app-shell {
    display: flex;
  }
  
  /* SIDEBAR */
  .sidebar {
    width: 270px;
    height: 100vh;
    background: #0b1220;
    color: white;
    position: fixed;
    left: 0;
    top: 0;
    padding: 15px;
    overflow-y: auto;
    transition: 0.3s;
  }
  
  /* LOGO */
  .logo {
    font-size: 18px;
    font-weight: bold;
    margin-bottom: 20px;
  }
  
  /* ITEMS */
  .item {
    display: block;
    padding: 10px;
    color: white;
    text-decoration: none;
    border-radius: 8px;
    margin-bottom: 5px;
  }
  
  .item:hover {
    background: #1e293b;
  }
  
  /* AI BUTTON (highlighted) */
  .ai {
    background: #2563eb;
  }
  
  /* SECTION HEADER */
  .section {
    margin-top: 15px;
    padding: 8px;
    cursor: pointer;
    color: #94a3b8;
    font-weight: bold;
  }
  
  /* SUB MENU */
  .submenu {
    display: none;
    margin-left: 10px;
  }
  
  .sub {
    display: block;
    padding: 8px;
    color: #cbd5e1;
    text-decoration: none;
    border-radius: 6px;
  }
  
  .sub:hover {
    background: #1e293b;
  }
  
  /* MOBILE */
  .mobile-btn {
    display: none;
    position: fixed;
    top: 10px;
    left: 10px;
    background: #0b1220;
    color: white;
    padding: 10px;
    border-radius: 8px;
    cursor: pointer;
  }
  
  /* RESPONSIVE */
  @media (max-width: 768px) {
    .sidebar {
      left: -270px;
    }
  
    .sidebar.active {
      left: 0;
    }
  
    .mobile-btn {
      display: block;
    }
  }