js如何实现内容复制

<div class="content">
  <p id="text">18336072281</p>
  <textarea id="input">18336072281</textarea>
  <button onclick="copyText()">复制</button>
</div>
//然后设置css
  .content {
      position: relative;
      display: flex;
      justify-content: center;
      align-items: center;
    }
    #input {
      position: absolute;
      top: 0;
      left: 0;
      opacity: 0;
      z-index: -10;
    }

function copyText() {
  var text = document.getElementById("text").innerText;
  var input = document.getElementById("input");
  input.value = text; 
  input.select(); 
    document.execCommand("copy"); 
}