Answers for "margin 0px auto"

margin 30px auto

/* La propriété s'applique aux quatre côtés */
margin: 1em;

/* vertical | horizontal */
margin: 5% auto;

/* haut | horizontal | bas */
margin: 1em auto 2em;

/* haut | droit | bas | gauche */
margin: 2px 1em 0 auto;


/* Valeurs globales */
margin: inherit;
margin: initial;
margin: unset;

margin 0 auto

Specifying 0 tells the browser to set the top and bottom margin to 0.

Specifying auto tells the browser to automatically determine the left
and right margins equally.

It's the same as:

margin-top:0;
margin-bottom:0;
margin-left:auto;
margin-right:auto;