<div class="ly_grid ly_grid__gap_xs">
  <div class="ly_grid_col">
    <button class="el_btn el_btn__plain el_btn__primary hp_fx_full" type="button">ボタンA</button>
  </div>
  <div class="ly_grid_col">
    <button class="el_btn el_btn__outline el_btn__danger hp_fx_full" type="button">ボタンB</button>
  </div>
</div>