JSFiddle - React, Tailwind, and code Playground

HTML

<div class="container">
  <textarea rows="3" placeholder="Hello"></textarea>
</div>

CSS

.container {
  width: 200px;
  border: 1px solid green;
  position: relative;
  overflow: hidden;
}
.container:before, .container textarea {
  font-family: sans-serif;
  font-size: 20px;
}
.container textarea {
  width: 100%;
  box-sizing: border-box;
  background-color: transparent;
  border: 0;
  outline: none;
  display: block;
  line-height: 1.2;
}
.container:before {
  position: absolute;
  content: "____________________\A____________________";
  z-index: -1;
  left: 0;
  top: 0;
  width: 100%;
  color: silver;
  line-height: 1.4;  
}