Curious why the top and bottom margins of 10px are not applied to the inner div in the snippet below. If I set the inner display property to "inline-block" it applies the top/bottom margins as expected.
HTML:
<div class="outer">
    <div class="inner">
        My content...
    </div> 
</div> 
CSS:
.outer {
    background-color: lightgrey;
}   
.inner {
    background-color: green;
    padding: 50px;
    width: 600px;
    margin:10px;
    display: block; /* No top, bottom margins applied.  Does apply them with "inline-block".  Why? */ 
}
 
     
    