.wrap-video {position: relative;background: url(/_res/nsu/dxtechmgmtscience/img/content/bg-video.png)no-repeat center;background-size: 100% 100%;background-position-y: 200px;z-index: 10;}	
.wrap-video:before {content: "";position: absolute;top: 200px;left: 0;width: 100%;height: calc(100% - 200px);z-index: -1;background: #EDEDED;opacity: 0.5}
.box-video {max-width: 1200px;margin: 0 auto;padding: 0 30px 300px;height: 700px;}

@media (max-width: 1024px){
	.box-video {max-width: 800px;height: 400px;}
}

@media (max-width: 768px){
	.wrap-video {background-position-y: 100px;}
	.wrap-video:before{height: calc(100% - 100px);top: 100px;}
	.box-video {height: calc(350/768*100vw);padding: 0 30px calc(200/768*100vw);}
}