JSFiddle - React, Tailwind, and code Playground

by David Simpson

HTML

<div class="image">
  <img src="http://placekitten.com/1410/500">
  <div class="pointer">
    <div class="triangleWrapper">
      <div style="height: 100%;" class="lefttriangle"></div>
    </div>
    <div class="triangleWrapper">
      <div style="height: 100%;" class="righttriangle"></div>
    </div>
  </div>
</div>

CSS

body,
html {
  height: 100%
}
.image {
  width: 1410px;
  margin-right: auto;
  margin-left: auto;
  height: 500px;
  overflow: hidden;
  position: relative;
}
.pointer {
  height: 50px;
  position: absolute;
  bottom: 0;
  left: 0;
  width: 100%;
}
.triangleWrapper {
  width: 50%;
  height: 50px;
  float: left;
}
.lefttriangle {
  width: 100%;
  height: 10px;
  left: 0px;
  top: 0px;
  background-image: linear-gradient(to right top, #ffffff 50%, transparent 50%);
}
.lefttriangle {
  width: 100%;
  height: 10px;
  left: 0px;
  top: 0px;
  background-image: linear-gradient(to right top, #ffffff 48%, transparent 50%); /* note the change of stop and start points */
}
.righttriangle {
  width: 100%;
  height: 10px;
  right: 0px;
  top: 0px;
  background: linear-gradient(to left top, #ffffff 50%, transparent 50%)
}