JSFiddle - React, Tailwind, and code Playground

HTML

<html>
  <body>
    <div class="container">
      <div class="content-area">
        <button>A</button>
        <button>B</button>
        <button>C</button>
        <button>D</button>
        <button>E</button>
        <input type="text">
      </div>
      <div class="submit-area">
        <button>
        Choose
        </button>
      </div>
    </div>
  </body>
</html>

CSS

html,body {
  width: 100%;
  height: 100%;
  padding: 0;
  margin: 0;
}

.container {
  height: 100vh;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 1rem;
}

.content-area {
  flex-grow: 1;
  display: flex;
  flex-direction: column;
  justify-content: space-evenly;
  align-items: center;
}

.content-area button {
  padding: 1em;
  font-weight: bold;
  width: 4rem;
  height: 4rem;
}

.submit-area {
  flex-grow: 0;
  display: flex;
  height: 20vh;
}