Answers for "how to align a div to center of the screen"

center a div in css

.container {
  display: flex;
  justify-content: center;
  align-items: center;
}

center div in middle of page

.centered {
  position: fixed;
  top: 50%;
  left: 50%;
  /* bring your own prefixes */
  transform: translate(-50%, -50%);
}

align div to center of screen

div.the-center-div {
	margin: 0 auto;
}