/* Default (mobile): stack, with button last */
.den-estimate .den-row {
  display: block;
}
.den-estimate .den-col--content { order: 1; }
.den-estimate .den-col--btn {
  order: 2;
  margin-top: 12px; /* space above the stacked button */
}
.den-estimate .den-col--btn .checkout-button {
  width: 100%;
  text-align: center;
}

/* Tablet & desktop: row, button vertically centered on right */
@media (min-width: 768px) {
  .den-estimate .den-row {
    display: flex;
    align-items: center;         /* vertical middle */
    justify-content: space-between;
    gap: 16px;
  }
  .den-estimate .den-col--content {
    flex: 1 1 auto;
    min-width: 0;
  }
  .den-estimate .den-col--btn {
    flex: 0 0 auto;
    margin-top: 0;               /* remove mobile spacing */
    display: flex;
    align-items: center;         /* center the button within its column */
  }
  .den-estimate .den-col--btn .checkout-button {
    width: auto;
    white-space: nowrap;
  }
}

/* If your cart layout breakpoint is 1000px, switch 768px -> 1000px above */