HTML Entity Escaper

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>HTML Entity Escaper</title>
  <style>
    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }

    body {
      font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
      background: #1a1a1a;
      min-height: 100vh;
      padding: 0;
      margin: 0;
      display: flex;
      align-items: center;
      justify-content: center;
    }

    .container {
      background: #1a1a1a;
      padding: 30px;
      width: 100%;
      height: 100vh;
      display: flex;
      flex-direction: column;
    }

    h1 {
      color: #333;
      margin-bottom: 10px;
      font-size: 28px;
    }

    .description {
      color: #999;
      margin-bottom: 25px;
      font-size: 14px;
    }

    .section {
      margin-bottom: 25px;
      flex: 1;
      display: flex;
      flex-direction: column;
    }

    label {
      display: block;
      margin-bottom: 8px;
      color: #aaa;
      font-weight: 600;
      font-size: 14px;
    }

    textarea {
      width: 100%;
      flex: 1;
      padding: 12px;
      background: #2d2d2d;
      color: #e0e0e0;
      border: 2px solid #404040;
      border-radius: 8px;
      font-family: 'Courier New', monospace;
      font-size: 14px;
      resize: none;
      transition: border-color 0.3s;
    }

    textarea:focus {
      outline: none;
      border-color: #667eea;
    }

    #output {
      background: #252525;
    }

    button {
      background: #667eea;
      color: white;
      border: none;
      padding: 12px 24px;
      border-radius: 8px;
      font-size: 16px;
      font-weight: 600;
      cursor: pointer;
      transition: background 0.3s, transform 0.1s;
      width: 100%;
    }

    button:hover {
      background: #5568d3;
    }

    button:active {
      transform: scale(0.98);
    }

    button.copied {
      background: #48bb78;
    }

    @media (max-width: 600px) {
      .container {
        padding: 20px;
      }

      h1 {
        font-size: 24px;
      }

      textarea {
        min-height: 120px;
        font-size: 13px;
      }
    }
  </style>
</head>
<body>
  <div class="container">
    <p class="description">Escape HTML entities: &lt; &gt; &amp; " '</p>

    <div class="section">
      <label for="input">Input Text:</label>
      <textarea id="input" placeholder="Paste your text here..."></textarea>
    </div>

    <div class="section">
      <label for="output">Escaped Output:</label>
      <textarea id="output" readonly></textarea>
    </div>

    <button id="copyBtn">Copy to Clipboard</button>
  </div>

  <script>
    const input = document.getElementById('input');
    const output = document.getElementById('output');
    const copyBtn = document.getElementById('copyBtn');

    function escapeHtml(text) {
      return text
        .replace(/&/g, '&amp;')
        .replace(/</g, '&lt;')
        .replace(/>/g, '&gt;')
        .replace(/"/g, '&quot;')
        .replace(/'/g, '&#39;');
    }

    input.addEventListener('input', () => {
      output.value = escapeHtml(input.value);
    });

    copyBtn.addEventListener('click', async () => {
      if (output.value) {
        try {
          await navigator.clipboard.writeText(output.value);
          copyBtn.textContent = 'Copied!';
          copyBtn.classList.add('copied');

          setTimeout(() => {
            copyBtn.textContent = 'Copy to Clipboard';
            copyBtn.classList.remove('copied');
          }, 1500);
        } catch (err) {
          output.select();
          document.execCommand('copy');
          copyBtn.textContent = 'Copied!';
          copyBtn.classList.add('copied');

          setTimeout(() => {
            copyBtn.textContent = 'Copy to Clipboard';
            copyBtn.classList.remove('copied');
          }, 1500);
        }
      }
    });
  </script>
</body>
</html>