body {
  margin: 0;
  overflow: hidden;
  font-family: Arial, sans-serif;
}

#viewer {
  width: 100vw;
  height: 100vh;
}

#panel {
  position: absolute;
  top: 10px;
  left: 10px;
  width: 300px;
  max-height: 90vh;
  overflow: auto;
  background: rgba(255,255,255,0.95);
  padding: 10px;
  border-radius: 8px;
  box-shadow: 0 0 10px rgba(0,0,0,0.2);
}

button {
  margin: 4px;
  padding: 5px 10px;
}