* {
      box-sizing: border-box;
    }

    body {
      margin: 0;
      padding: 0;
      font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
      background-color: #f4f6f9;
      color: #444;
      display: flex;
      align-items: center;
      justify-content: center;
      height: 100vh;
      text-align: center;
    }

    .container {
      padding: 20px;
      max-width: 90%;
    }

    .error-code {
      font-size: 10rem;
      font-weight: 800;
      color: #e0e0e0;
      margin-bottom: 0;
      line-height: 1;
    }

    .error-image {
      width: 100%;
      max-width: 300px;
      margin: 0 auto 20px;
    }

    h1 {
      font-size: 1.8rem;
      margin: 10px 0;
      color: #333;
    }

    p {
      font-size: 1rem;
      color: #666;
      margin-bottom: 30px;
    }

    .btn {
      display: inline-block;
      padding: 12px 24px;
      background-color: #00bcd4;
      color: white;
      text-decoration: none;
      border-radius: 8px;
      font-weight: bold;
      transition: background 0.3s ease;
    }

    .btn:hover {
      background-color: #0097a7;
    }

    @media (max-width: 480px) {
      .error-code {
        font-size: 6rem;
      }

      h1 {
        font-size: 1.5rem;
      }

      p {
        font-size: 0.95rem;
      }

      .btn {
        width: 100%;
        padding: 14px;
        font-size: 1rem;
      }
    }