*{box-sizing:border-box}
html,body{margin:0;width:100%;height:100%;overflow:hidden;background:#fff}
body{-webkit-user-select:none;user-select:none}
#app{position:fixed;inset:0;width:100vw;height:100dvh;background:#fff;overflow:hidden}
#teacher{position:absolute;inset:0;width:100%;height:100%;display:block;object-fit:cover;object-position:center top}
#mic{position:fixed;left:50vw;top:72vh;transform:translate(-50%,-50%);width:108px;height:108px;margin:0;padding:0;border:8px solid #fff;border-radius:50%;background:#19c84b;box-shadow:0 8px 24px rgba(0,0,0,.24);z-index:9999;display:none;align-items:center;justify-content:center;-webkit-tap-highlight-color:transparent;touch-action:manipulation}
#mic.show{display:flex}
.micIcon{position:relative;width:30px;height:44px;border:6px solid #fff;border-radius:17px;font-size:0}
.micIcon:before{content:"";position:absolute;left:50%;top:31px;transform:translateX(-50%);width:46px;height:24px;border:5px solid #fff;border-top:0;border-radius:0 0 24px 24px}
.micIcon:after{content:"";position:absolute;left:50%;top:51px;transform:translateX(-50%);width:5px;height:13px;background:#fff;border-radius:4px;box-shadow:-10px 13px 0 -1px #fff,10px 13px 0 -1px #fff}