[destus]

<style>
  body,
  html {
    height: 100%;
    padding: 0;
    margin: 0;
  }

  .a {
    display: grid;
    height: 100%;
    grid-auto-rows: min-content 1fr min-content;
  }
</style>

<div class="a">
  <div class="b">b</div>
  <div class="c">c</div>
  <div class="d">d</div>
</div>