demo.html

<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
    <style>
      body {
        display: flex;
        flex-direction: column;
        align-items: center;
        justify-content: center;
        height: 100vh;
      }
      button {
        width: auto;
        height: 50px;
        background-color: #007bff;
        border: none;
        border-radius: 5px;
        cursor: pointer;
        color: white;
      }

      textarea {
        width: 400px;
        height: 100px;
        margin-top: 50px;
      }
    </style>
  </head>
  <body>
    <button>Unselectable text in a button</button>
    <div>
      <textarea name="" id=""></textarea>
    </div>
  </body>
</html>