Tiny Minimal Flexbox Grid

flexbox.css

.flex-grid {
  display: flex;
}
.col {
  flex: 1;
}

/* Break on mobile? */
@media (max-width: 400px) {
  .flex-grid {
    display: block;
  }
}


/*
Credits, gutters, margins and more:
https://css-tricks.com/dont-overthink-flexbox-grids/
*/

flexbox.html

<div class="flex-grid">
  <div class="col"></div>
  <div class="col"></div>
  <div class="col"></div>
</div>