body{background: black;}
.wrap{display: flex; justify-content: center;}
.center{display: flex; justify-content: center;}
.center .box{max-width: 100%;margin: 10px 0;}
.center .box img{max-width: 100%;max-height: 95vh;}
.btn {height: 100px;display: flex; justify-content: center;}
#btn,#prg{width: 320px;height: 72px;margin:20px;}