html, body {
      height: 100%;
      margin: 0;
      display: flex;
      flex-direction: column;
    }

    main {
      flex: 1;
    }
    footer {
      background-color: #065599;
      color: white;
      padding: 2rem 1rem;
      text-align: center;
    }
    .popup {
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.5);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 9999;
    animation: fadeIn 0.3s ease-in;
  }

  .popup.hidden {
    display: none;
  }

  .popup-content {
    position: relative;
    background: #fff;
    color: #343a40;
    border-radius: 12px;
    padding: 25px 30px;
    max-width: 90%;
    width: 340px;
    text-align: center;
    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.2);
    animation: slideIn 0.4s ease-out;
    border-left: 6px solid #343a40;
  }

  .popup-content h2 {
    color: #065498;
    font-size: 1.4rem;
    margin-bottom: 15px;
  }

  .popup-content p {
    font-size: 1rem;
    color: #343a40;
    line-height: 1.4;
  }

  .install-button {
    margin-top: 20px;
    padding: 10px 20px;
    background-color: #065498;
    color: white;
    font-size: 1rem;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    transition: background-color 0.2s ease-in-out;
  }

  .install-button:hover {
    background-color: #05417a;
  }

  .popup .close {
    position: absolute;
    top: 10px;
    right: 15px;
    font-size: 1.5rem;
    font-weight: bold;
    color: #888;
    cursor: pointer;
  }

  @keyframes slideIn {
    from { transform: translateY(-40px); opacity: 0; }
    to { transform: translateY(0); opacity: 1; }
  }

  @keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
  }

.back-button {
  position: fixed;
  bottom: 100px; /* fica 80px acima dos botões que estão a 20px */
  right: 20px;
  border-radius: 50px;
  padding: 10px 20px;
  font-weight: 500;
  text-decoration: none;
  background-color: #6d6d6d5f;
  color: black;
  box-shadow: 0 2px 6px rgba(0,0,0,0.2);
  transition: background-color 0.3s ease;
  z-index: 1200;  /* para ficar acima dos botões fixos */
  border: none; /* remove borda */
  outline: none; /* remove contorno de foco */
}

.back-button:hover {
  background-color: #424243;
  color: white;
}

.back-button:focus {
  outline: none;
  box-shadow: none; /* remove sombra de foco do navegador */
}