html, body {
  height: 100%;
  width: 100%;
  background-color: #000000;
  overflow: hidden; /* impede scroll */
}

body {
  position: fixed; /* garante que não vai ter scroll extra */
}

#molecules {
  display: block;
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  background-color: #000000; /* fundo preto garantido */
  border: none;
  outline: none;
  z-index: -1;
}