/* Variáveis CSS */
    :root {
      --primary-color: #1A3C40; /* Verde esmeralda */
      --primary-hover: #27ae60; /* Verde mais escuro */
      --accent-color: #27ae60; /* Dourado suave */
      --background-start: #f0f4f8; /* Azul claro */
      --background-end: #e8f0fe; /* Azul mais claro */
      --text-primary: #1a202c; /* Cinza escuro */
      --text-secondary: #6b7280; /* Cinza médio */
      --text-error: #e53e3e; /* Vermelho */
      --card-background: #ffffff; /* Branco puro */
      --border-color: #e2e8f0; /* Cinza claro */
      --shadow: 0 6px 20px rgba(0, 0, 0, 0.08); /* Sombra suave */
      --border-radius: 16px; /* Bordas mais arredondadas */
      --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1); /* Transição suave */
      --focus-ring: 0 0 0 3px rgba(46, 204, 113, 0.3);
      --gradient-bg: linear-gradient(135deg, #dae7de 0%, #e0f2fe 100%); /* Subtle modern gradient */
    }

    /* Reset e configurações globais */
    *, *::before, *::after {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }

    body {
      font-family: 'Poppins', sans-serif;
      background: var(--gradient-bg);
      color: var(--text-primary);
      min-height: 100vh;
      padding: clamp(1rem, 4vw, 2rem);
      line-height: 1.6;
      -webkit-font-smoothing: antialiased;
      -moz-osx-font-smoothing: grayscale;
    }

    /* Contêiner principal */
    .container {
      max-width: 720px;
      margin: 0 auto;
      width: 100%;
    }

    /* Cabeçalho */
    .header {
      display: flex;
      justify-content: space-between;
      align-items: center;
      margin-bottom: clamp(1.5rem, 3vw, 2rem);
    }

    .header h1 {
      font-size: clamp(1.5rem, 5vw, 2rem);
      font-weight: 700;
      letter-spacing: -0.02em;
      background: linear-gradient(90deg, var(--primary-color), var(--accent-color));
      -webkit-background-clip: text;
      background-clip: text;
      color: transparent;
    }

    /* Botão de voltar */
    .btn-back {
      display: inline-flex;
      align-items: center;
      gap: 0.5rem;
      text-decoration: none;
      color: var(--primary-color);
      font-weight: 600;
      font-size: 1rem;
      transition: color var(--transition), transform var(--transition);
    }

    .btn-back i {
      font-size: 1.25rem;
      transition: transform var(--transition);
    }

    .btn-back:hover {
      color: var(--primary-hover);
      transform: translateX(-0.25rem);
    }

    .btn-back:hover i {
      transform: scale(1.1);
    }

    .btn-back:focus-visible {
      outline: var(--focus-ring);
      outline-offset: 2px;
    }

    /* Card principal */
    .card {
      background: var(--card-background);
      border-radius: var(--border-radius);
      padding: clamp(1.5rem, 4vw, 2rem);
      box-shadow: var(--shadow);
      transition: transform var(--transition), box-shadow var(--transition);
      position: relative;
      overflow: hidden;
    }

    .card::before {
      content: '';
      position: absolute;
      top: 0;
      left: 0;
      width: 100%;
      height: 4px;
      background: linear-gradient(90deg, var(--primary-color), var(--accent-color));
      opacity: 0.8;
    }

    .card:hover {
      transform: translateY(-6px);
      box-shadow: 0 12px 32px rgba(0, 0, 0, 0.1);
    }

    /* Logo */
    .logo {
      text-align: center;
      margin-bottom: 2rem;
    }

    .logo img {
      max-width: 200px;
      height: auto;
      display: block;
      margin: 0 auto;
      transition: transform var(--transition);
    }

    .logo img:hover {
      transform: scale(1.05);
    }

    /* Loader */
    .loader {
      display: none;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      min-height: 120px;
      animation: fadeIn 0.4s ease;
    }

    .loader.active {
      display: flex;
    }

    .loader i {
      font-size: 2.5rem;
      color: var(--primary-color);
      animation: spin 1s linear infinite;
    }

    .loader p {
      margin-top: 1rem;
      font-size: 0.875rem;
      color: var(--text-secondary);
      font-weight: 400;
    }

    /* Informações do plano */
    .plan-info {
      background: rgba(47 226 123 / 26%);
      padding: 1rem;
      border-radius: 10px;
      margin-bottom: 1.5rem;
    }

    .plan-info h2 {
      font-size: clamp(1.25rem, 3vw, 1.5rem);
      font-weight: 600;
      margin-bottom: 0.5rem;
      color: var(--text-primary);
    }

    .plan-info p {
      font-size: 0.9375rem;
      color: var(--text-secondary);
      margin-bottom: 0.25rem;
    }

    /* Formulário de pagador */
    .payer-info {
      margin-top: 1.5rem;
    }

    .payer-info .form-group {
      position: relative;
      margin-bottom: 1.25rem;
    }

    .payer-info label {
      display: block;
      font-size: 0.875rem;
      font-weight: 500;
      margin-bottom: 0.5rem;
      color: var(--text-primary);
    }

    .payer-info input {
      width: 100%;
      padding: 0.75rem 2.5rem 0.75rem 1rem;
      border: 1px solid var(--border-color);
      border-radius: 8px;
      font-size: 1rem;
      transition: border-color var(--transition), box-shadow var(--transition);
      background: #f7fafc;
    }

    .payer-info input:focus {
      border-color: var(--primary-color);
      box-shadow: var(--focus-ring);
      outline: none;
    }

    .payer-info input:invalid[aria-invalid="true"] {
      border-color: var(--text-error);
    }

    .payer-info .form-group i {
      position: absolute;
      right: 1rem;
      top: 50%;
      transform: translateY(-50%);
      color: var(--text-secondary);
      font-size: 1rem;
      transition: color var(--transition);
    }

    .payer-info input:focus + i {
      color: var(--primary-color);
    }

    .payer-info .error-text {
      display: none;
      color: var(--text-error);
      font-size: 0.75rem;
      margin-top: 0.25rem;
    }

    .payer-info input:invalid[aria-invalid="true"] ~ .error-text {
      display: block;
    }

    /* Botão de pagamento */
    .payer-info button {
      width: 100%;
      padding: 1rem;
      background: linear-gradient(90deg, var(--primary-color), var(--accent-color));
      color: #fff;
      border: none;
      border-radius: 8px;
      font-size: 1rem;
      font-weight: 600;
      cursor: pointer;
      transition: background var(--transition), transform var(--transition), box-shadow var(--transition);
      position: relative;
      overflow: hidden;
    }

    .payer-info button::after {
      content: '';
      position: absolute;
      top: 50%;
      left: 50%;
      width: 0;
      height: 0;
      background: rgba(255, 255, 255, 0.3);
      border-radius: 50%;
      transform: translate(-50%, -50%);
      transition: width 0.4s ease, height 0.4s ease;
    }

    .payer-info button:hover::after {
      width: 200px;
      height: 200px;
    }

    .payer-info button:disabled {
      background: #cbd5e0;
      cursor: not-allowed;
      transform: none;
    }

    .payer-info button:not(:disabled):hover {
      transform: translateY(-2px);
      box-shadow: 0 4px 12px rgba(46, 204, 113, 0.3);
    }

    .payer-info button:not(:disabled):focus-visible {
      outline: var(--focus-ring);
    }

    /* Mensagem de erro global */
    .error-message {
      display: none;
      color: var(--text-error);
      font-size: 0.875rem;
      text-align: center;
      margin-top: 1rem;
      animation: fadeIn 0.3s ease;
      background: rgba(229, 62, 62, 0.1);
      padding: 0.5rem;
      border-radius: 6px;
    }

    .error-message.active {
      display: block;
    }

    /* Contêiner do Pix */
    .pix-container {
      display: none;
      margin-top: 2rem;
      text-align: center;
      animation: fadeIn 0.5s ease;
      background: rgba(46, 204, 113, 0.05);
      padding: 1.5rem;
      border-radius: 10px;
    }

    .pix-container.active {
      display: block;
    }

    .pix-container h3 {
      font-size: clamp(1.125rem, 3vw, 1.375rem);
      font-weight: 600;
      margin-bottom: 0.75rem;
      color: var(--text-primary);
    }

    .pix-container p {
      font-size: 0.875rem;
      color: var(--text-secondary);
      margin: 0.5rem 0;
    }

    .pix-container img {
      max-width: 220px;
      margin: 1rem auto;
      border-radius: 8px;
      box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
      border: 2px solid var(--primary-color);
      transition: transform var(--transition);
    }

    .pix-container img:hover {
      transform: scale(1.02);
    }

    #pix-code {
      font-family: 'Courier New', monospace;
      word-break: break-all;
      background: #edf2f7;
      padding: 1rem;
      border-radius: 8px;
      margin: 1rem auto;
      max-width: 100%;
      font-size: 0.8125rem;
      border: 1px solid var(--border-color);
      position: relative;
    }

    #pix-code::after {
      content: '\f0c5';
      font-family: 'boxicons';
      position: absolute;
      top: 0.5rem;
      right: 0.5rem;
      color: var(--primary-color);
      cursor: pointer;
      font-size: 1rem;
    }

    #pix-status {
      font-weight: 600;
      color: var(--primary-color);
      margin-top: 1rem;
      animation: pulse 2s infinite;
    }

    /* Animações */
    @keyframes fadeIn {
      from { opacity: 0; transform: translateY(10px); }
      to { opacity: 1; transform: translateY(0); }
    }

    @keyframes spin {
      to { transform: rotate(360deg); }
    }

    @keyframes pulse {
      0%, 100% { opacity: 1; }
      50% { opacity: 0.7; }
    }

    /* Responsividade */
    @media (max-width: 480px) {
      body {
        padding: 1rem;
      }

      .container {
        max-width: 100%;
      }

      .header h1 {
        font-size: 1.25rem;
      }

      .btn-back {
        font-size: 0.875rem;
      }

      .card {
        padding: 1.25rem;
      }

      .logo img {
        max-width: 160px;
      }

      .payer-info input {
        padding: 0.625rem 2rem 0.625rem 0.875rem;
        font-size: 0.9375rem;
      }

      .payer-info button {
        padding: 0.875rem;
        font-size: 0.9375rem;
      }

      .pix-container img {
        max-width: 180px;
      }

      #pix-code {
        font-size: 0.75rem;
      }
    }