JSFiddle - React, Tailwind, and code Playground

HTML

<div class="cont">
        <div class="inner1"></div>
        <div class="inner2"></div>
        <div class="inner3"></div>
    </div>

CSS

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}
.cont {
  min-height: 150vh;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
}

.inner1, .inner2, .inner3 {
  width: 100%;
  display: flex;
  background: gold;
  flex: 1;
}

.inner2 {
  background: brown;
}
.inner3 {
  background: palegoldenrod;
}