style.css

body {
    /* background: #eee; */
}
#defaultCanvas0 {
    max-width: 100% !important;
    height: auto !important;
}

#app {
    border-radius: 5px;
    background: #fff;
    overflow: hidden;
    box-shadow: 0 5px 30px rgba(0, 0, 0, 0.25);
}

#mainCanvas {
    padding: 0;
    
}

.btn, .btn-group {
    width: 100%;
    color: white;
    border-radius: 0;
}

video {
    opacity: 0;
}