odin-css-exercises/animation/02-pop-up/solution/solution.css

* {
  padding: 0;
  margin: 0;
}

body {
  overflow: hidden;
}

.button-container {
  width: 100vw;
  height: 100vh;
  background-color: #ffffff;
  opacity: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
}

button {
  padding: 20px;
  color: #ffffff;
  background-color: #0e79dd;
  border: none;
  border-radius: 5px;
  font-weight: 600;
}

.popup-modal {
  padding: 32px 64px;
  background-color: white;
  border: 1px solid black;
  border-radius: 10px;
  position: fixed;
  top: 50%;
  left: 50%;
  transform-origin: center;
  transform: translate(-50%, -50%);
  pointer-events: none;
  opacity: 0%;
  text-align: center;
}
.popup-modal p {
  margin-bottom: 24px
}

.backdrop {
  pointer-events: none;
  position: fixed;
  inset: 0;
  background: #000;
  opacity: 0%;
}

.popup-modal.show {
  opacity: 100%;
  pointer-events: all;
}

.backdrop.show {
  opacity: 30%;
}

/* SOLUTION */

.popup-modal {
  transition: transform .3s ease-in-out, opacity .4s ease;
  transform: translate(-50%, -100%);
}

.popup-modal.show {
  transform: translate(-50%, -50%);
}