body{margin:0;font-family:Arial,sans-serif;background-color:#1a1a1a;color:#fff;display:flex;justify-content:center;align-items:center;height:100vh}.app{text-align:center;padding:20px}.video-container{position:relative;display:inline-block}.video-placeholder{width:480px;height:360px;display:flex;align-items:center;justify-content:center;background:linear-gradient(135deg,#232526,#414345);border-radius:12px;box-shadow:0 0 20px #00000080;color:#bbb;font-size:1.3em;font-weight:500;letter-spacing:1px;position:relative;margin-bottom:10px;border:2px dashed #444}.video-placeholder .placeholder-icon{font-size:3em;margin-right:16px;opacity:.7}video{border-radius:10px;box-shadow:0 0 10px #fff3}canvas.overlay{position:absolute;top:0;left:0}.emotion-label{margin-top:12px;font-size:20px;font-weight:700}.controls{margin:20px 0}button{margin:0 8px;padding:10px 18px;font-size:16px;font-weight:700;border:none;border-radius:8px;cursor:pointer}.start-btn{background-color:#4caf50;color:#fff}.stop-btn{background-color:#f44336;color:#fff}