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overflow: hidden;

Responsible design에서 풀스크린 video영역을 제어하는 tip입니다.

 In order to embed the video and along with that inflate full width to the boundary, 
we have a very useful CSS trick for all developers.

.video {
position: relative;
padding-bottom: 56.25%;
height: 0;
overflow: hidden;
}
.video iframe,
.video object,
.video embed {
position: absolute;
top: 0;
left: 0;
width: 100%;
height: 100%;
}