.banner-box {
	width: 100%;
	height: 600px;
	display: flex;
	justify-content: center;
	overflow: hidden;
	position: relative;
}

.banner-img-box {
	width: 100%;
	/* 或者具体的像素值 */
	height: 600px;
	/* 初始高度设为0 */
	background-image: url('../imgs2/aboutUs_PIC.jpg');
	background-position: center;
	background-size: cover;
	/* 覆盖整个盒子 */
	/* 图片居中 */
	background-repeat: no-repeat;
	position: absolute;
	top: 0;
	left: 0;
}

.big-img {
	width: 100%;
	/* 或者具体的像素值 */
	height: 0;
	/* 初始高度设为0 */
	padding-top: 183%;
	/* 百分比与宽度相同，保持宽高比 */
	background-image: url('../imgs2/aboutUs2.png');
	background-size: contain;
	/* 覆盖整个盒子 */
	background-position: center;
	/* 图片居中 */
	background-repeat: no-repeat;
	background-attachment: scroll;
}


@media screen and (max-width:1200px) {
	.banner-box,
	.banner-img-box {
		height: 500px;
	}

	.marginleft {
		margin: 0;
	}
}

@media screen and (max-width:991px) {}

@media screen and (max-width:767px) {
	.banner-box,
	.banner-img-box {
		height: 350px;
	}
}

@media screen and (max-width:576px) {
	.big-img {
		width: 100%;
		/* 或者具体的像素值 */
		height: 0;
		/* 初始高度设为0 */
		padding-top: 495%;
		/* 百分比与宽度相同，保持宽高比 */
		background-image: url('../imgs2/aboutUs.png');
		background-size: contain;
		/* 覆盖整个盒子 */
		background-position: center;
		/* 图片居中 */
		background-repeat: no-repeat;
		background-attachment: scroll;
	}

	.banner-box {
		height: 275px;
	}

	.banner-img-box {
		height: 275px;
		background-image: url('../imgs2/aboutUs_PIC2.jpg');
	}
}