body {
      background: url("/static/wood.png") no-repeat center center fixed;
      background-size: cover;
      font-family: Arial, sans-serif;
    }
    .login-box {
      background: white;
      border-radius: 12px;
      box-shadow: 0 0 15px rgba(0, 0, 0, 0.1);
      padding: 2rem;
      width: 620px;
      margin: 5% auto;
    }
    .step { display: none; }
    .step.active { display: block; }
    .otp-input {
      width: 40px;
      font-size: 1.5rem;
      text-align: center;
      margin: 0 5px;
    }
    .brand-logo {
      display: block;
      margin: 0 auto 1rem;
      height: 50px;
    }
    .btn-toggle {
      border-radius: 20px;
      width: 100px;
    }
    .fade-in {
      animation: fadeIn 0.5s ease-in-out;
    }
    @keyframes fadeIn {
      from { opacity: 0; }
      to { opacity: 1; }
    }
    a {
      text-decoration: none;
    }