JSFiddle - React, Tailwind, and code Playground
HTML
<div class="test"></div>
CSS
.test {
border-left: 33px solid transparent;
border-right: 33px solid transparent;
height: 33px;
background: linear-gradient(0deg, black, red);
margin: 0 auto;
min-width: 42px;
background-clip: content-box;
position: relative;
}
.test:before, .test:after {
content: '';
position: absolute;
width: 45px;
height: 45px;
bottom: 0px;
}
.test:before {
-webkit-transform: rotate(45deg);
-webkit-transform-origin: bottom right;
background: linear-gradient(-45deg, black 0, red 32px, transparent 32px);
right: 100%;
}
.test:after {
-webkit-transform: rotate(-45deg);
-webkit-transform-origin: bottom left;
background: linear-gradient(45deg, black 0, red 32px, transparent 32px);
left: 100%;
}