* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html,
body {
    width: 100%;
    height: 100%;
    overflow: hidden;
    background: transparent;
}

.intro-stage,
.intro-scene {
    width: 100%;
    height: 100%;
}

canvas {
    display: block;
    width: 100%;
    height: 100%;
    background: transparent;
}