html, body {

margin: 0;
padding: 0;

width: 100%;
height: 100%;

overflow: hidden;

}

a-scene {

position: fixed;

top: 0;
left: 0;

width: 100%;
height: 100%;

}

#ytButton {

position: fixed;

bottom: 20px;
right: 20px;

padding: 12px 18px;

font-size: 16px;

border-radius: 8px;

background: red;
color: white;

border: none;

z-index: 999;

}