.webgl{position:fixed;top:0;left:0;visibility:hidden;opacity:0}body.xr-presenting .webgl{visibility:visible;opacity:1}html,body{overflow:hidden;margin:0;padding:0;width:100%;height:100%;background-color:#505050}body:before{content:"Start WebXR";position:fixed;top:50%;left:50%;transform:translate(-50%,-50%);background:#A377FF;color:#fff;padding:20px 40px;border-radius:10px;font-family:Arial,sans-serif;font-size:18px;font-weight:700;z-index:1000;pointer-events:none;transition:opacity .3s ease}body.xr-presenting:before{opacity:0}body.webxr-error:before{display:none}#VRButton,button[id*=XR],button[id*=VR],button[class*=xr],button[class*=vr]{display:none!important;visibility:hidden!important;opacity:0!important;pointer-events:none!important}.webxr-error-message{position:fixed;top:50%;left:50%;transform:translate(-50%,-50%);background:#ff4444;color:#fff;padding:20px 40px;border-radius:10px;font-family:Arial,sans-serif;font-size:18px;text-align:center;z-index:1001;max-width:400px;line-height:1.5}.webxr-error-message a{color:#fff;font-weight:700;text-decoration:underline}.webxr-error-message a:hover{color:#ffeb3b}