JSFiddle - React, Tailwind, and code Playground

HTML

<div class="all-copy">
  <p><span>One click selects all this</span>.</p>
</div>

CSS

div {
  padding: 20px;
  margin: 20px;
  background: #eee;
}
.all-copy p span {  
  -webkit-user-select: all;  /* Chrome all / Safari all */
  -moz-user-select: all;     /* Firefox all */
  -ms-user-select: all;      /* IE 10+ */
  user-select: all;          /* Likely future */   
}