div {
	border: 1px solid red;
	/* https://developer.mozilla.org/ru/docs/Web/CSS/display */
	display: block;
	/* https://developer.mozilla.org/ru/docs/Web/CSS/flex */
	flex: content;
	/* https://developer.mozilla.org/ru/docs/Web/CSS/position */
	position: absolute;
	top: 0px;
}