how to place a div exactly at the center of the screen code example

Example 1: center div in middle of page

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

Example 2: vertically and horizontally center a fixed div

// you dont need to know the divs dimensions and it does not require any container divs
position: fixed; 
top: 50%;
left: 50%;
transform: translate(-50%, -50%);