.videobox {
  /*  position: relative;*/
   
    width: 100%;
    height: 0;
    padding-bottom: 56.25%; /*影片高度與寬度的比例 16:9 計算得來。*/
	top:15%;
    left:15%;	
	
	position:fixed;
     z-index:999; 
	 transform:translate(-50%,0%);
	
	
}

.videobox iframe {
	position:fixed;
   /* position: absolute;*/
    width: 70%;
    height: 70%;
}

.B_b {
   /* position: absolute;*/
   	padding: 0;
    margin: 0;
	position:fixed;
    width: 100%;
    height:100%;
	z-index:998;
    top: 0;
    left: 0;
	
/*	transform:translate(-50%,-45%);*/
}


.B_b input{
   /* position: absolute;*/
    width: 100%;
    height: 100%;
	
	border:0;
	background:url(../images/closelabel.gif) no-repeat; /*背景圖片 顯示一次*/
	background-color:rgba(150,150,150,0.5); /*背景顏色*/
	background-attachment:fixed;
	background-position:top;
	cursor:pointer;
	border:2px #acacac solid;
}