https://codepen.io/ananyaneogi/pen/RzZQRL 

HTML : 

<h1>Editing page content</h1>

<div class="edit" contenteditable>
You can edit me...and add as much ye wish!
</div>

CSS : 

body {
	display: flex;
	flex-direction: column;
	justify-content: center;
	align-items: center;
	padding 40px;
}

h1 {
	font-size: 3rem;
	color: mediumaquamarine;
	font-family: "Berkshire Swash", cursive;
	text-align: center;
}

.edit {
	width: 80%; 
	height: 100%; 
	min-height: 51vh;
	outline: none;
	color: #333;
	font-family: "Berkshire Swash", cursive;
	font-size: 1.2rem;
	line-height: 1.56;
	margin: 30px;
	padding: 30px 50px;
	position: relative;
	border: 1px solid #DFE8EC;
	background: -webkit-linear-gradient(top, #DFE8EC 0%, white 8%) 0 56px;
	background: -moz-linear-gradient(top, #DFE8EC 0%, white 8%) 0 56px;
	background: linear-gradient(top, #DFE8EC 0%, white 8%) 0 56px;
	-webkit-background-size: 100% 30px;
	-moz-background-size: 100% 30px;
	background-size: 100% 30px;
}

.edit:before {
	content: '';
	position: absolute;
	top: 0;
	left: 30px;
	width: 1px;
	height: 100%;
	border: 1px solid indianred;
	opacity: 0.5;
}