@media (max-width: 768px) {
	html {
		font-size: 56.3%;
	}
}
@media (min-width: 768px) and (max-width: 896px) {
	html {
		font-size: 68.75%;
	}
}
@media (max-width: 896px) {
	body:after {
		display: none;
	}
	#header .inner {
		padding: 0;
	}
	#header .current {
		line-height: 1rem
	}
	#header .hsubject {
		border-left: 0
	}
	#header .hgroup h1 {
		line-height: 1;
	}
	#header .hgroup p {
		/*position: absolute;
		left: 1.125rem;*/
		display: none;
	}
	#header .util-menu {
		min-width: auto;
		padding-right: 1.125rem;
	}
	#app {
		width: 100%;
		max-width: none;
		max-height: none;
	}
	#content .content-inner {
		margin: 0 15px;
	}
	#footer .video-js {
	}

	.intro .content {
		float: none
	}
	.layer-wrap .close {
		top: -2.812rem;
		right: 0;
		left: auto;
	}
	[data-page="intro"] .photo {
		max-width: 36%;
		right: 0;
	}

	.video-js .vjs-control:before {
		line-height: 1.67;
	}

	.theorem .utils {
		top: auto;
		bottom: 1.875rem;
	}
	.exercise dl dt:after {
		left: 0;
	}

	.next-lecture .list {
		padding: 1.125rem 1.25rem;
	}

	.next-lecture ul li {
		padding: 0.4375rem 0.5rem;
	}

	.next-lecture ul li .num,
	.next-lecture ul li .title {
		display: block;
		width: 100%;
	}

	.next-lecture ul li .num {
		line-height: 2.187rem;
	}
	.next-lecture ul li .title {
		padding: 0.1875rem 0.5rem;
		box-sizing: border-box;
	}

	.next-lecture .next {
		height: 8.75rem;
	}

	.video-js .vjs-control-bar .vjs-volume-menu-button {
		display: none;
	}

	[data-page="lecture"] .video-js .vjs-tech,
	[data-page="orientation"] .video-js .vjs-tech {
		padding: 5.25rem 15px 4.125rem 15px;
	}
	[data-page="lecture"] .video-js .vjs-fullscreen-control {
		display: block;
	}
	[data-page="lecture"] .video-js .vjs-control-bar .vjs-volume-menu-button {
		border-right: 1px solid #363636;
	}
	.video-js .vjs-control-bar .vjs-play-control {
		border-right: 0;
	}
	[data-page="lecture"] .video-js .vjs-control-bar .vjs-play-control {
		border-right: 1px solid #363636;
	}
	[data-page="lecture"] .video-js .vjs-fullscreen-control {
		border-left: 1px solid #000;
	}

	.is-touch .vjs-volume-menu-button {
		display: none;
	}
	/* .professor-think .photo img {
		max-width: 60%;
	} */
	.pc-view{
		display:none;
	}
	.m-view{
		display:block;
	}
	.exercise dl {
		width: 100%;
		padding-right: 18px;
	}
	.tab {
		width: 25%;
	}
	.tab-contents {
		width: 75%
	}
	.tab button {
		padding-left: 10px;
		padding-right: 10px;
	}
	.site-guide .tab-content {
		max-height: 430px;
	}
}
@media (max-width: 896px) and (orientation:landscape) {
	body {
		min-height: 280px;
	}
	.professor-think{
		height:30%;
	}
	.professor-think .photo img {
		max-width: 100%;
	}
}
@media (max-width: 414px) {
	#header .util-menu .lesson,
	#header .util-menu .sound,
	#footer .logo {
		display: none;
	}
	.step-wrap .step {
		float: none;
		width: auto;
		padding-left: 0;
	}
}