how to align item center css code example

Example 1: how to align items in css

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

Example 2: alignitems

/* Basic keywords */ 
align-items: normal; 
align-items: stretch; 

/* Positional alignment */ 
/* align-items does not take left and right values */
align-items: center; /* Pack items around the center */ 
align-items: start; /* Pack items from the start */ 
align-items: end; /* Pack items from the end */ 
align-items: flex-start; /* Pack flex items from the start */ 
align-items: flex-end; /* Pack flex items from the end */

/* Baseline alignment */
align-items: baseline; 
align-items: first baseline; 
align-items: last baseline; /* Overflow alignment (for positional alignment only) */ 
align-items: safe center; 
align-items: unsafe center; 

/* Global values */
align-items: inherit; 
align-items: initial; 
align-items: unset;

Example 3: center a div

<div id="outer">
  <div id="inner">Foo foo</div>
</div>
//css:, demo with border
<style>
#inner {
  display: table;
  margin: 0 auto;
  border: 1px solid black;
}

#outer {
  border: 1px solid red;
  width:100%
}
</style>

Example 4: center element in div

/* html */
<h1>Centering with CSS</h1>

<h3>Text-Align Method</h3>
<div class="blue-square-container">
  <div class="blue-square"></div>
</div>

<h3>Margin Auto Method</h3>
<div class="yellow-square"></div>

<h3>Absolute Positioning Method</h3>
<div class="green-square"></div>

/* css */
h1,
h3 {
  text-align: center;
}

.blue-square-container {
  text-align: center;
}

.blue-square {
  background-color: #0074D9;
  width: 100px;
  height: 100px;
  display: inline-block;
}