@nguyenmv2/buy-button/src/styles/embeds/sass/components/buttons.css

BuyButton.js allows merchants to build Shopify interfaces into any website

.shopify-buy__btn {
  color: #fff;
  font-size: 15px;
  background-color: var(--color-primary);
  padding: 12px 40px;
  letter-spacing: .3px;
  display: block;
  border-radius: 3px;
  cursor: pointer;
  transition: background 200ms ease;
  max-width: 100%;
  text-overflow: ellipsis;
  overflow: hidden;
  line-height: 1.2;
  border: 0;
  -moz-appearance: none;
  -webkit-appearance: none;

  &:hover,
  &:focus {
    background-color: var(--color-primary-hover);
  }
}

.shopify-buy__btn--parent {
  background-color: transparent;
  border: 0;
  padding: 0;
  cursor: pointer;

  &:hover,
  &:focus {
    & .product__variant-img {
      opacity: .7;
    }
  }
}

.shopify-buy__btn--cart-tab {
  padding: 5px 11px;
  border-radius: 3px 0 0 3px;
  position: fixed;
  right: 0;
  top: 50%;
  transform: translate(100%, -50%);
  opacity: 0;
  min-width: inherit;
  width: auto;
  height: auto;
  z-index: var(--max-z-index);

  &.is-active {
    transform: translateY(-50%);
    opacity: 1;
  }
}

.shopify-buy__btn__counter {
  display: block;
  margin: 0 auto 10px auto;
  font-size: 18px;
}

.shopify-buy__icon-cart--side {
  height: 20px;
  width: 20px;
}

.shopify-buy__btn[disabled] {
  background-color: #999;
  pointer-events: none;
}

.shopify-buy__btn--close {
  position: absolute;
  right: 9px;
  top: 8px;
  font-size: 35px;
  color: var(--color-cart-title);
  border: none;
  background-color: transparent;
  transition: transform 100ms ease, color 100ms ease;
  cursor: pointer;
  font-family: "Helvetica Neue", Helvetica, Arial, sans-serif;
  padding-right: 9px;

  &:hover {
    transform: scale(1.2);
    color: color-mod(var(--color-cart-title) lightness(-5%));
  }
}