html, body {
      height: 100%;
      margin: 0;
      background-color: #121212;
      color: #eee;
    }
    body {
      display: flex;
      flex-direction: column;
      font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    }
    #navbar {
      flex: 0 0 auto;
      box-shadow: 0 2px 8px rgba(0,0,0,0.5);
    }
    #contentFrame {
      flex: 1 1 auto;
      width: 100%;
      border: none;
      background-color: white;
      box-shadow: inset 0 0 15px rgba(0,0,0,0.2);
    }
    .btn-group, .form-select {
      min-width: 140px;
    }
    #controls {
      gap: 12px;
    }
    .navbar-brand {
      font-weight: 700;
      font-size: 1.3rem;
      letter-spacing: 1px;
      color: #61dafb !important;
      user-select: none;
    }
    .btn-primary {
      background-color: #0d6efd !important;
      border-color: #0d6efd !important;
      transition: background-color 0.3s ease;
    }
    .btn-primary:hover {
      background-color: #0b5ed7 !important;
      border-color: #0b5ed7 !important;
    }
    .session-item {
      display: flex;
      justify-content: space-between;
      align-items: center;
      margin-bottom: 8px;
      padding: 6px 0;
      border-bottom: 1px solid #333;
    }
    .session-item:last-child {
      border-bottom: none;
    }
    .session-url {
      font-size: 0.85rem;
      word-break: break-all;
      flex-grow: 1;
      margin-right: 10px;
    }
    .session-actions button {
      margin-left: 4px;
      font-size: 0.75rem;
    }
    #toggleSessionList {
      background-color: #343a40;
      color: #eee;
      border: 1px solid #495057;
    }
    #toggleSessionList:hover {
      border-color: #61dafb;
      box-shadow: 0 0 5px #61dafb;
    }
 .dropdown-arrow {
    font-size: 0.8rem;
    transition: transform 0.2s ease;
  }
  #sessionList.show + #toggleSessionList .dropdown-arrow {
    transform: rotate(180deg);
  }