$ bu YourHexPrivateKey

  <h1>Cryptos.Host Provably Fair Verification</h1>
  <label for="cSeed">Enter Client Seed (Decimal):</label>
  <input type="text" id="cSeed"><br>
  <label for="sSeed">Enter Server Seed (Hexadecimal):</label>
  <input type="text" id="sSeed"><br>
  <button onclick="verify()">Verify</button>
  <div id="result"></div>

    function XOR(c, s) {
      let o = '';
      for (let i = 0; i < c.length; i++) {
        const a = parseInt(c.charAt(i), 16);
        const b = parseInt(s.charAt(i), 16);
        o += (a ^ b).toString(16);
      }
      return o;
    }

    function pfResult(cSeed, sSeed) {
      const resHex = XOR(('0000000'+cSeed.toString(16)).substr(-8), sSeed);
      return {resHex: resHex, resInt: parseInt(resHex, 16)};
    }

    function verify() {
      const cSeed = parseInt(document.getElementById('cSeed').value);
      const sSeed = document.getElementById('sSeed').value;
      const result = pfResult(cSeed, sSeed);
      document.getElementById('result').innerHTML = `Result (Hex): ${result.resHex}<br>Result (Integer): ${result.resInt}`;
    }