So W3C states that the h1 element has default margins as followed:

HTML Code:
h1 {
display: block;
font-size: 2em;
margin-before: 0.67em;
margin-after: 0.67em;
margin-start: 0;
margin-end: 0;
font-weight: bold; }
But when clear all default margins using the following code, my h1 tag still renders margins before and after. Why is this when all other elements have no margins under my css rule?

HTML Code:
* {
margin: 0;
padding 0: