css center div

.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 {
     margin: 0 auto;
     width: 100px; 
}
.parent {
  position: relative;
}
.child {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
}<!-- 
	 Simple CSS CENTER DIV Example
 	 
	 * See Fiddle in link for PoC *
-->

<div class="parent">
  <div class="child">
    <p>
      Eh Up Me Duck!
    </p>
  </div>
</div>

<style>
.parent {
  /* Just for aesthetics: see fiddle */
  border: 1px solid black;
  padding: 2px;
}

.child {
  border: 1px solid red;
  width: 50%;
  
  /* This is where the magic happens */
  margin-left: auto;
  margin-right: auto;
  /**********************************/
}

p {
  /* As you do */
  text-align: center;
}
</style>div.center{display:block;margin:auto;width:50%;}
p.center{text-align:center;}/* this will center all children within the parent element. */
.parent {
  display: flex;
  justify-content: center; /* horizontal */
  align-items: center; /* vertical */
}