.content {
  width: 100%;
  height: 100%;
  margin: 0 auto;
  padding: 0px;
  background: #556677;
  min-height: 100%;
  position: fixed;
}

.openbox, .closebox{
  color: white;
  padding: 0px 0px;
  font-family: Arial, Baskerville, monospace;
  border-radius: 0px;
  cursor: pointer;
}

.closebox{
    height: 0px;
    width: 0px;
	position: absolute;
    margin-top: 50px;
	margin-right: 90px;
    top: 10px;
    right: 0px;
    -webkit-user-select: none;
    -moz-user-select: none;
    user-select: none;
    font-family: Arial, Baskerville, monospace;
    font-size: 100px;
    display: block;
    text-align: center;
    padding-right: 0px;
    color: #07B9D0;
}
.videowrap {
    display: none;
    position: absolute;
    width: 100%;
    height: 100%;
    top: 0;
    left: 0;
    background: rgba(0,0,0,.9);
    min-height: 100%;
    position: fixed;
    border-radius: 0px;
}

#video{
  width: 600px;
  height: 400px;
  position: absolute;
  left: 50%;
  margin-left: -300px;
  top: 50%;
  margin-top: -200px;
}

@media (max-width: 720px) {
	
#video{
  width: 90%; /* you can use % */
  height: auto;
  min-height: 300px;
  position: absolute;
  margin-left: -200px;
  margin-top: -200px;
  padding-right: 5%;
  padding-left: 5%;
}
	
.closebox{
    height: 0px;
    width: 0px;
	position: absolute;
    margin-top: 100px;
	margin-right: 60px;
    top: 0;
    right: 0;
    -webkit-user-select: none;
    -moz-user-select: none;
    user-select: none;
    font-family: Arial, Baskerville, monospace;
    font-size: 40px;
    box-sizing: border-box;
    padding-top: 0px;
    padding-left: 20px;
    padding-bottom: 40px;
    display: block;
    text-align: center;
    border-radius: 40px;
    padding-right: 20px;
    color: #07B9D0;
}

	}