div.ban_img {
	position: relative;
	height: 320px;
	background: url(../img/train.jpg) no-repeat center center;
	background-size: auto 100%;
}

div.train-text {
	position: absolute;
	top: 13%;
	left: 18%;
	padding: 30px 0 0 33PX;
	width: 300px;
	height: 160px;
	background: rgba(218,221,226,.9);
	line-height: 3;
}

h2.t_b {
	color: #227bcf;
	letter-spacing: 1rem;
	font-weight: 700;
	font-size: 40px;
}

@media (min-width:900px) {
	div.course {
		margin: 80px auto;
		width: 850px;
		height: 540px;
	}

	video {
		width: 850px;
		height: 540px;
	}
}

@media (max-width:768px) {
	div.course {
		margin: 0 auto;
		padding-top: 27px;
		width: 100%;
		max-width: 85%;
	}

	video {
		width: 100%;
		height: 100%;
	}
	div.train-text {
		width: 260px;
	}
}