<style>
  .grid-container {
    display: grid;
    background-color: lightsalmon;
  }

  .grid-item {
    background-color: lightblue;
  }
</style>

<div class="grid-container" style="
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  ">
  <div class="grid-item">1</div>
  <div class="grid-item">2</div>
  <div class="grid-item">3</div>
</div>