@charset "utf-8"; 
*{
	margin: 0;
	padding: 0;
	box-sizing: border-box;
}
body{
	background-color: black;
}
img{
    max-width:100%;
    height:auto;
	display: block;
}
video {
    width: 700px;
}

.flag_top,.flag,.flag_foot{
	width: 700px;
	margin: 0px auto;
}
.flag_top img,
.flag img,
.flag_foot img{
	width: 100%;
}
.no{
	display: none;
}
.btn{
	cursor: pointer;
}

.flag_top{
	position: relative;
}

.fixed-btn {
      position: absolute;
      top: 63px;       /* 距底部30px */
      left: 53px;        /* 距右侧30px */
     
	  width: 5vw;
      border: none;
      cursor: pointer;
    
      z-index: 1000;      /* 确保置顶显示 */
     
    }



/* 视频 */
.video-container {
  position: relative;
  padding-bottom: 56.25%; /* 16:9 宽高比 */
  height: 0;
  overflow: hidden;
}

.video-container video {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
}

/* 视频结束 */

@media (max-width:1000px){
	
	.fixed-btn {
		width: 14vw;
	}
	
	
}


@media (max-width: 480px){
	.flag_top,.flag,.flag_foot{
		width: 100%;
		margin: 0px auto;
	}
	
	.fixed-btn {
		top: 20px;       /* 距底部30px */
		left: 20px;        /* 距右侧30px */
		width: 18vw;
		
	}
	
	video {
	    width: 100%;
	}
	
	
	/* 视频 */
	.video-container {
	  position: relative;
	  padding-bottom: 56.25%; /* 16:9 宽高比 */
	  height: 0;
	  overflow: hidden;
	}
	
	.video-container video {
	  position: absolute;
	  top: 0;
	  left: 0;
	  width: 100%;
	  height: 100%;
	}
	
	/* 视频结束 */
}