body, html {
  margin: 0;
  padding: 0;
  width: 100%;
  height: 100%;
  overflow: hidden;
  font-family: sans-serif;
}

.viewer {
  width: 100vw;
  height: 100vh;
  background: linear-gradient(to bottom, #BFC9C9 0%, #8E9B9B 100%);
  outline: none; 
}

/* STILE PULSANTE MINIMAL */
.top-right-btn {
  position: absolute;
  top: 20px;
  right: 20px;
  z-index: 100; /* Sopra al viewer */
  
  background-color: rgba(255, 255, 255, 0.4); /* Sfondo semitrasparente */
  backdrop-filter: blur(5px); /* Effetto vetro sfocato */
  border: 1px solid rgba(255, 255, 255, 0.6);
  border-radius: 20px;
  
  padding: 10px 20px;
  color: #333;
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
  
  transition: all 0.3s ease;
  box-shadow: 0 4px 6px rgba(0,0,0,0.1);
}

.top-right-btn:hover {
  background-color: rgba(255, 255, 255, 0.8);
  transform: translateY(-2px);
  box-shadow: 0 6px 12px rgba(0,0,0,0.15);
}

.top-right-btn:active {
  transform: translateY(0);
}