body {
      font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
      background: linear-gradient(135deg, #4CAF50, #8BC34A);
      margin: 0;
      padding: 0;
      display: flex;
      justify-content: center;
      align-items: center;
      height: 100vh;
    }

    .container {
      background: #fff;
      padding: 30px;
      border-radius: 20px;
      box-shadow: 0 6px 15px rgba(0,0,0,0.2);
      width: 400px;
      max-width: 90%;
      text-align: center;
      animation: fadeIn 1s ease-in-out;
    }

    h2 {
      margin-bottom: 20px;
      color: #333;
    }

    .input-group {
      margin-bottom: 15px;
      text-align: left;
    }

    label {
      display: block;
      font-weight: bold;
      margin-bottom: 5px;
      color: #444;
    }

    input {
      width: 100%;
      padding: 10px;
      border-radius: 8px;
      border: 1px solid #ccc;
      transition: 0.3s;
    }

    input:focus {
      border-color: #4CAF50;
      outline: none;
      box-shadow: 0 0 5px rgba(76,175,80,0.5);
    }

    button {
      background: #4CAF50;
      color: white;
      border: none;
      padding: 12px;
      border-radius: 10px;
      font-size: 16px;
      cursor: pointer;
      width: 100%;
      transition: 0.3s;
    }

    button:hover {
      background: #45a049;
    }

    .result {
      margin-top: 20px;
      padding: 15px;
      border-radius: 10px;
      background: #e8f5e9;
      color: #2e7d32;
      font-weight: bold;
      display: none;
    }

    @keyframes fadeIn {
      from { opacity: 0; transform: translateY(-20px); }
      to { opacity: 1; transform: translateY(0); }
    }