JSFiddle - React, Tailwind, and code Playground

HTML

<div class="subsection bg">
    <div class="coolarrow bg"></div>
</div>

CSS

.bg {
    background: #36c;
    background: 
    linear-gradient(115deg, transparent 75%, rgba(255,255,255,.8) 75%) 0 0,
    linear-gradient(245deg, transparent 75%, rgba(255,255,255,.8) 75%) 0 0,
    linear-gradient(115deg, transparent 75%, rgba(255,255,255,.8) 75%) 7px -15px,
    linear-gradient(245deg, transparent 75%, rgba(255,255,255,.8) 75%) 7px -15px, #36c;
    background-size: 15px 30px;
}

div.subsection {
    margin-top: 100px;
    width: 100%;
    height: 100px;
    
   -moz-box-shadow:    inset 0 0 10px #000000;
   -webkit-box-shadow: inset 0 0 10px #000000;
   box-shadow:         inset 0 0 10px #000000;
}

div.coolarrow {
    margin-left: 45px;
    width: 70.7px;
    height: 50%;
    position: relative;
}

div.coolarrow:before {
    content: '';
    position: absolute;
    z-index: -1;
    top: -24.7px;
    left: 10px;
    background-color: #bada55;
    width: 50px;
    height: 50px;
    
    background: #36c;
    background: 
    linear-gradient(115deg, transparent 75%, rgba(255,255,255,.8) 75%) 0 0,
    linear-gradient(245deg, transparent 75%, rgba(255,255,255,.8) 75%) 0 0,
    linear-gradient(115deg, transparent 75%, rgba(255,255,255,.8) 75%) 7px -15px,
    linear-gradient(245deg, transparent 75%, rgba(255,255,255,.8) 75%) 7px -15px, #36c;
    background-size: 15px 30px;
    
   -moz-box-shadow:    inset 0 0 10px #000000;
   -webkit-box-shadow: inset 0 0 10px #000000;
   box-shadow:         inset 0 0 10px #000000;
    
    -webkit-transform: rotate(45deg); 
    -moz-transform: rotate(45deg);  
    filter: progid:DXImageTransform.Microsoft.BasicImage(rotation=5); /*for IE*/
}