#install-app {
  position:absolute; top:20.451%; left:37.5%; width:25%; height:10.399%; z-index:10;
  box-sizing:border-box; padding:0; border:1px solid #fff; border-radius:6px;
  color:#fff; background:#1c4216; font:calc(11px * var(--app-scale, 1)) Arial,sans-serif;
  white-space:nowrap; cursor:pointer;
}
#install-app[hidden] { display:none; }
#install-app:hover:not(:disabled) { background:#305c21; }
#install-app:active:not(:disabled) { background:#b86e1d; }
#install-app:focus-visible { outline:3px solid #ffd441; outline-offset:2px; }
#install-app:disabled { cursor:default; opacity:1; }
#install-app.is-installed { background:#666; color:#fff; border-color:#ddd; }
#install-help { color:#fff; background:#254b1b; border:1px solid #fff; border-radius:12px;
  width:min(380px,calc(100vw - 48px)); box-sizing:border-box; padding:24px;
  font:16px/1.7 Arial,sans-serif; }
#install-help::backdrop { background:rgba(0,0,0,.55); }
#install-help h2 { font-size:20px; margin:0 0 12px; }
#install-help form { text-align:right; margin-top:20px; }
#install-help button { font:inherit; color:#fff; background:#b86e1d; border:1px solid #fff;
  padding:6px 20px; border-radius:6px; cursor:pointer; }