:root {
      --color-fondo: #f8f9fa;
      --color-texto: #222;
      --color-borde: #e0e0e0;
      --color-boton: #fff;
      --color-hover: #f1f1f1;
      --radio: 12px;
      --espaciado: 16px;
      --sombra: 0 4px 12px rgba(0, 0, 0, 0.06);
    }

    * {
      box-sizing: border-box;
    }

    body {
      margin: 0;
      font-family: 'Segoe UI', sans-serif;
      background: var(--color-fondo);
      color: var(--color-texto);
      display: flex;
      justify-content: center;
      align-items: center;
      min-height: 100vh;
      padding: var(--espaciado);
    }

    .container {
      background: #fff;
      border-radius: var(--radio);
      box-shadow: var(--sombra);
      padding: 40px 24px;
      max-width: 420px;
      width: 100%;
      text-align: center;
    }

    .logo-wrapper {
      display: flex;
      justify-content: center;
      margin-bottom: 20px;
    }

    .logo-wrapper img {
      width: 64px;
      height: auto;
    }

    .titulo-principal {
      font-size: 1.8rem;
      font-weight: 600;
      text-align: center;
      margin: 0;
      color: #111;
    }

    .subtitulo-principal {
      font-size: 1.1rem;
      font-weight: 400;
      text-align: center;
      margin-top: 4px;
      margin-bottom: 24px;
      color: #555;
    }

    p.subtitulo {
      font-size: 0.95rem;
      color: #666;
      margin-bottom: 32px;
    }

    .btn {
      display: flex;
      align-items: center;
      width: 100%;
      text-align: left;
      padding: 16px;
      font-size: 1rem;
      font-weight: 500;
      border: 1px solid var(--color-borde);
      border-radius: var(--radio);
      background: var(--color-boton);
      color: #333;
      margin-bottom: 16px;
      cursor: pointer;
      transition: background 0.3s;
      text-decoration: none;
    }

    .btn:hover {
      background: var(--color-hover);
    }

    .btn svg {
      margin-right: 12px;
      width: 20px;
      height: 20px;
      stroke: #666;
    }

    @media (max-width: 480px) {
      .container {
        padding: 24px 16px;
      }

      .titulo-principal {
        font-size: 1.5rem;
      }

      .btn {
        font-size: 0.95rem;
        padding: 14px;
      }
    }