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

html, body {
    width: 100%;
    height: 100%;
    overflow: hidden;
    background: #000;
}

#app {
    width: 100%;
    height: 100%;
}

/* Three.js manages the canvas size via inline styles — don't override it here */
#app canvas {
    display: block;
}