Dawn Theme quick add Choose Option open a transparent modal that hard to read.

[himclinic]

As you can see here, it open a modal, but the modal itself is transparent and hard to read. I just want it to be white background.

[himclinic]

Never mind, I found it. 

Assets->quick-add.css

.quick-add-modal__content {
  position: absolute;
  top: 0;
  left: 50%;
  transform: translateX(-50%);
  margin: 3.2rem auto 0;
  width: 100%;
  background-color: #ffffff;
  overflow: hidden;
  max-width: var(--page-width);
  width: calc(100% - 3rem);
}

I adjust the background color to #ffffff.