JSFiddle - React, Tailwind, and code Playground

HTML

<div class="arrow_box"><span></span>Lorem ipsum dolor sit amet, consectetur adipisicing elit.</div>

CSS

body {
    background: #444 url('http://leaverou.me/ft2010/img/darker_wood.jpg') bottom;
}

.arrow_box {
    color:red;
	position: relative;
	background: #88b7d5;
	border: 4px solid #c2e1f5;
    height:400px;
    border-radius:0 300px 0 0;
}
.arrow_box:after, .arrow_box:before { 
    -ms-transform:rotate(-135deg);
    -webkit-transform:rotate(-135deg); 
     transform:rotate(-135deg);
	bottom: 100%;
	border: solid transparent;
	content: " ";
	height: 0;
	width: 0;
	position: absolute;
    top:42px;
    right:-20px;
}

.arrow_box:after {
	border-color: rgba(200, 265, 0, 0);
	border-bottom-color: #00b7d5;
	border-width: 100px;
	left: 100%;
	margin-left: -240px;
}
.arrow_box:before {
	border-color: rgba(194, 225, 245, 0);
	border-bottom-color: #c2e1f5;
	border-width: 105px;
	left: 100%;
    top:39px;
	margin-left: -245px;
}

.arrow_box span {
    border-top: 4px solid #c2e1f5;
    position:absolute;
    width:150px;
    height:140px;
    background-color:black;
    right:140px;
    top:-4px;
    background: #88b7d5;
}

.arrow_box span:after {
    border-right: 4px solid #c2e1f5;  
    content: "";
    position:absolute;
    width:150px;
    height:150px;
    background: #88b7d5;
    left:140px;
    top:140px;
}