:root{
  --bg:#ffffff;
  --fg:#111;
  --muted:#666;
  --accent:#000;
  font-family: "Noto Sans", system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial;
}

*{box-sizing:border-box}
html,body{height:100%}
body{
  margin:0;
  background:var(--bg);
  color:var(--fg);
  display:flex;
  align-items:center;
  justify-content:center;
  padding:24px;
}

.container{
  width:100%;
  max-width:520px;
  text-align:center;
}

.app-icon{
  width:96px;
  height:96px;
  object-fit:contain;
  border-radius:18px;
  display:block;
  margin:0 auto 12px;
  background:transparent;
}

h1{margin:6px 0 4px;font-size:22px}
.lead{margin:0 0 18px;color:var(--muted)}

.instructions{
  text-align:left;
  background:#fafafa;
  border:1px solid #eee;
  padding:16px;
  border-radius:10px;
}

.instructions h2{font-size:16px;margin:0 0 8px}
.instructions ol{margin:0 0 8px 18px;color:var(--muted)}
.note{font-size:13px;color:var(--muted);margin-bottom:12px}

.actions{display:flex;gap:8px}
button{
  flex:1;
  padding:10px 12px;
  border-radius:8px;
  border:1px solid #ddd;
  background:#fff;
  cursor:pointer;
  font-weight:600;
}
button:active{transform:translateY(1px)}
.msg{margin-top:12px;color:var(--accent);font-size:14px}

/* full-screen embed styles */
.embed-frame{
  position:fixed;
  inset:0;
  width:100%;
  height:100%;
  border:0;
  z-index:9999;
  background:#fff;
}

/* hide any residual or dynamically-added close / back button to ensure no close control is shown */
#embed-close, .embed-close, .iframe-close,
.back-button, .btn-back, #btnBack, .close-btn, #close, .btn-close,
button[aria-label="Close"], button[aria-label="close"],
button[aria-label="Back"], button[aria-label="back"],
a[rel="back"], a.back, .topbar .close, .topbar .back {
  display: none !important;
  pointer-events: none !important;
  visibility: hidden !important;
  width:0 !important;
  height:0 !important;
  opacity:0 !important;
}

/* additional defensive rules for potential browser UI overlays injected into page */
.toolbar, .nav-toolbar, .web-app-toolbar, .app-toolbar {
  display:none !important;
}

/* prevent outlines or visible focus for any hidden controls */
[aria-hidden="true"]{display:none !important}

/* footer */
.footer{margin-top:12px;text-align:center;color:var(--muted);font-size:13px}