CSS

center div horizontally and vertically

.parent {
  position: relative;
}
.child {
    position: absolute;
    left: 50%;
    top: 50%;
    transform: translate(-50%, -50%);
}

centre div vertically and horizontally

.name-of-div-to-be-centered {
  position: absolute;
  left: 50%;
  top: 50%;
  -webkit-transform: translate(-50%, -50%);
  transform: translate(-50%, -50%);
}

center align div vertically and horizontally css

.parent{
	display: flex;
    justify-content: center;
  	align-items: center;
}
/* Child elements will be perfectly centered automatically */

how to center a div vertically and horizontally

.container{	
	margin: 0;
    position: absolute;
    top: 50%;
    left: 50%;
    -ms-transform: translate(-50%, -50%);
    transform: translate(-50%, -50%);
  	width: /* Define the width here; */
    height: /* Define the height here; */
}

/*You have to define the width and height! */

center div inside div vertically and horizontally

        .contentCentralized {
            width: 100%;
            height : 200px; 			//Remove height if you don't want specified height for it
            display: flex;
            flex-direction: column; 	//options : row | row-reverse | column | column-reverse
            flex-wrap: wrap;        	//options : flex-start | flex-end | center | baseline | stretch
            justify-content: center;	//options : start |  center | space-between | space-around | space-evenly
            align-items: center;
        }
        <div class="contentCentralized">
        <h3>Hello Developers.</h3>
        </div>
        

how to center horizontally and vertically block div

#html code
<div class="parent">
	<h1 class="child">CSS is cool</h1>
</div>

#css code
.parent{
  display:grid;
  place-items:center;
  
  width:560px; 
  height: 560px;
}

how to center a div horizontally and vertically

.content {
        width: 200px;
        height: 600px;
        background-color: blue;
        position: absolute; /*Can also be `fixed`*/
        left: 0;
        right: 0;
        top: 0;
        bottom: 0;
        margin: auto;
        /*Solves a problem in which the content is being cut when the div is smaller than its' wrapper:*/
        max-width: 100%;
        max-height: 100%;
        overflow: auto;
}