Changing image sizes proportionally using CSS?

Question

I have been trying for a couple of days now to configure my thumbnail gallery so all the images appear the same height and width. However when I change the Css code to,

Answer 1

transform: scale(0.5);

---

Example:

Normal
Scaled

div {
  width: 80px;
  height: 80px;
  background-color: skyblue;
}

.scaled {
  transform: scale(0.7); /* Equal to scaleX(0.7) scaleY(0.7) */
  background-color: pink;
}

see: https://developer.mozilla.org/en-US/docs/Web/CSS/transform-function/scale