JSFiddle - React, Tailwind, and code Playground

HTML

<div class="wrap">
        <span>1</span>
        <span>1</span>
        <span>1</span>
        <span>1</span>
        <span>1</span>
        <span>1</span>
        <span>1</span>
        <span>1</span>
    </div>

CSS

.wrap{
font-size:0;
width:900px;
}

span{
display:inline-block;
font-size:14px;
background:red;
margin:0px 0px 20px 30px;
width:202px;
height:100px;
position:relative;
}

span:nth-child(4n+1){
margin-left:0px;
}

span:after{
content:'';
position:absolute;
width:20px;
height:20px;
bottom:0px;
right:-20px;
background:#ccc;
}