html,body {
	/* Firefox */
	background: -moz-linear-gradient(top, #fff,#fff 30%, #3DC2EC);
	/* Chrome , Safari */
	background: -webkit-linear-gradient(top, #fff,#fff 30%, #3DC2EC);
	/* IE11 */
	background: linear-gradient(to bottom, #fff, #fff 30%, #3DC2EC);
	/* 代用 */
	background-color: #fff;
}