set content inside a div horizontal align middle code example

Example 1: how to assign something in center inside a div

IMG.displayed {
    display: block;
    margin-left: auto;
    margin-right: auto }
...
<IMG class="displayed" src="..." alt="...">

Example 2: 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>