html,body{margin:0;height:100%;background:#000;overflow:hidden}
.stage{width:100vw;height:100vh;display:flex;align-items:center;justify-content:center}
.poster{position:relative;display:inline-block;max-width:100vw;max-height:100vh}
.poster img{display:block;max-width:100vw;max-height:100vh;width:auto;height:auto}
.btn{position:absolute;display:block;left:5.2%;width:12.2%;height:3.8%}
.b1{top:79.1%}.b2{top:84.5%}.b3{top:89.9%}