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                <div id="container">
      <h1>Caesars Cipher</h1>
        One of the simplest and most widely known ciphers is a
        <span>Caesar cipher</span>, also known as a <span>shift cipher</span>.
        In a shift cipher the meanings of the letters are shifted by some set
        amount. A common modern use is the <span>ROT13 cipher</span>, where the
        values of the letters are <span>shifted by 13 places</span>. Thus 'A' ↔
        'N', 'B' ↔ 'O' and so on.
      <div class="panel">
        <input id="inputText" type="text" placeholder="Type something..." />
        <div class="row">
          <select name="shifts" id="shift">
            <option value="1">1</option>
            <option value="2">2</option>
            <option value="3">3</option>
            <option value="4">4</option>
            <option value="5">5</option>
            <option value="6">6</option>
            <option value="7">7</option>
            <option value="8">8</option>
            <option value="9">9</option>
            <option value="10">10</option>
            <option value="11">11</option>
            <option value="12">12</option>
            <option value="13" selected>13</option>
            <option value="14">14</option>
            <option value="15">15</option>
            <option value="16">16</option>
            <option value="17">17</option>
            <option value="18">18</option>
            <option value="19">19</option>
            <option value="20">20</option>
            <option value="21">21</option>
            <option value="22">22</option>
            <option value="23">23</option>
            <option value="24">24</option>
            <option value="25">25</option>
          <button class="btn" id="clipboard">
            <i class="far fa-clipboard"></i>
        <button onclick="caesarShift(inputText.value, shift.value)">
        <button onclick="decrypt(inputText.value)">


                * {
  margin: 0;
  padding: 0;
  box-sizing: border-box;

body {
  font-family: "Muli", sans-serif;
  color: #fff;

#container {
  background-image: linear-gradient(60deg, #29323c 0%, #485563 100%);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;

#container h3 span {
  color: #fff;

h1 {
  color: white; /* Fallback */
  /*Photo by Freepik on Freepik -*/
  background: url(
  background-clip: text;
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  text-transform: uppercase;
  letter-spacing: 5px;
  font-family: "Archivo Black", "Arial Black", sans-serif;
  font-size: 8vw;

h3 {
  color: lightsteelblue;
  letter-spacing: 1px;
  text-align: center;
  margin: 0px 0px 20px;
  padding: 0px 50px;

.row {
  display: flex;
  flex-direction: row;

.panel {
  background-image: linear-gradient(#141e30, #243b55);
  border-radius: 15px;
  box-shadow: 0 5px 10px rgba(0, 0, 0, 0.3);
  padding: 30px;
  margin: 15px;

.panel input,
.panel button {
  border: none;
  border-radius: 3px;
  display: block;
  font-size: 16px;
  padding: 8px 10px;
  margin: 15px 0;
  width: 100%;

.panel select {
  border: none;
  border-radius: 3px;
  font-size: 16px;
  padding: 8px 10px;
  margin: 15px 0;
  width: 100%;

.panel .btn {
  font-size: 16px;
  padding: 8px 12px;
  margin-left: 15px;
  width: 100%;

.panel button {
  background-image: linear-gradient(to bottom right, #141e30, #243b55);
  border: 1px solid rgba(255, 255, 255, 0.3);
  color: #fff;
  cursor: pointer;

@media (max-width: 600px) {
  h3 {
    font-size: 14px;
    margin: 15px 0px 0px;



                function decrypt(isDecrypt) {
  var shiftText = document.getElementById("shift").value;
  var shift = parseInt(shiftText, 10);
  if (isDecrypt) shift = (26 - shift) % 26;
  var textElem = document.getElementById("inputText");
  textElem.value = caesarShift(textElem.value, shift);

function caesarShift(text, shift) {
  var shift = parseInt(shift, 10);
  var result = "";

  for (var i = 0; i < text.length; i++) {
    var c = text.charCodeAt(i);

    if (65 <= c && c <= 90)
      result += String.fromCharCode(((c - 65 + shift) % 26) + 65);
    // Uppercase
    else if (97 <= c && c <= 122)
      result += String.fromCharCode(((c - 97 + shift) % 26) + 97);
    // Lowercase
    else result += text.charAt(i);
  var textElem = document.getElementById("inputText");
  textElem.value = result;
  return result;

document.getElementById("clipboard").addEventListener("click", copyToClipboard);

function copyToClipboard() {
  let textArea = document.createElement("textarea");
  const emptyResultField = inputText.value;

  if (!emptyResultField) {
  textArea.value = inputText.value;

  alert("Caesaris codice copied to clipboard!");