body {
  background:#020617;
  color:#e5e7eb;
  font-family:system-ui,sans-serif;
}
.hidden { display:none; }
.lock, #app {
  max-width:600px;
  margin:auto;
  padding:20px;
}
section {
  background:#0f172a;
  padding:15px;
  border-radius:12px;
  margin-bottom:15px;
}
button {
  margin-top:10px;
}