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(90deg, black, blue);
  	margin: 0 auto;
  	min-width: 42px;
    background-clip: content-box;
    position: relative;
}

.test:before, .test:after {
    content: '';
    position: absolute;
    width: 33px;
    height: 100%;
}

.test:before {
    background: linear-gradient(45deg, transparent 50%, black 50%);
    right: 100%;
}

.test:after {
    background: linear-gradient(315deg, transparent 50%, blue 50%);
    left: 100%;
}