/* --- Base layout --- */
body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    margin: 0;
    padding: 0;
    background-color: #ffffff;
    color: #111;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: flex-start;
    min-height: 100vh;
  }
  
  /* --- Login screen --- */
  #login-container {
    display: flex;
    justify-content: center;
    align-items: center;
    height: 60px
  }
  
  #loginButton {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 10px;
    margin-top: 30px;
    text-align: center;
    cursor: pointer;
    transition: background-color 0.2s, transform 0.1s;
  }
  
  #loginButton:hover {
    background-color: #1ed760;
    transform: translateY(-1px);
  }
  
  /* --- Visualization container --- */
  #viz-container {
    display: none;
    width: 100%;
    max-width: 1200px;
    padding: 20px;
    box-sizing: border-box;
    text-align: center;
  }
  
  /* --- Logout container --- */
  #logout-container {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 10px;
    margin-top: 30px;
    text-align: center;
    cursor: pointer;
  }
  
  /* --- Logout button --- */
  #logoutButton {
    display: none; /* Hidden until logged in */
    padding: 6px 12px;
    font-size: 14px;
    font-weight: 600;
    border-radius: 6px;
    background-color: #f2f2f2;
    border: 1px solid #ccc;
    cursor: pointer;
    transition: background-color 0.2s, transform 0.1s;
  }
  
  #logoutButton:hover {
    background-color: #e2e2e2;
    transform: translateY(-1px);
  }
  
  /* --- Logged-in info text --- */
  #user-info {
    font-weight: 600;
    font-size: 15px;
    color: #111;
    display: flex;
    align-items: center;
    gap: 4px;
    margin-top: 0px;
    margin-bottom: 0px;
  }
  
  /* --- Global button style reset --- */
  button {
    font-family: inherit;
    outline: none;
  }
  
  /* --- Utility: responsive scaling --- */
  @media (max-width: 768px) {
    #loginButton {
      padding: 12px 28px;
      font-size: 16px;
    }
  
    #logout-container {
      flex-direction: column;
      gap: 6px;
    }
  }