Empêcher la marge de l'enfant de déplacer le parent CSS

/* Prevent Child Margin from Moving Parent */
.parent {
  margin: -1px;
  padding: 1px;
}
/* Alternatively */
.parent {
	display: flow-root; /* no supported by IE 11 */
}
/*
Learn more: https://www.w3.org/TR/CSS2/box.html#collapsing-margins
*/
sicaria