not_body {
  background: black;
  color: lime;
  font-family: monospace;
  margin: 0;
  padding: 0;
  display: flex;
  justify-content: center;
  align-items: flex-start;
}

html, body {
  height: 100%;
  margin: 0;
  padding: 0;
}

body {
  display: flex;
  justify-content: center;
  align-items: center;
  /* background: black url("assets/earth-background.png") center center no-repeat; */
  background: black;
  background-size: cover;
}

#gameContainer {
  width: 800px;
  height: 600px;
 /* margin: 40px auto; */
  text-align: center;
  /* background: black url("assets/starfield.png") center center no-repeat; */
  background: black url("assets/earth-background.png") center center no-repeat;
  background-size: cover;
  position: relative;
  display: flex;
  justify-content: center;
  align-items: center;
}

#game {
  display: block;
  border: 4px solid lime;
  /* background: black; */
}

canvas.hide-cursor {
  cursor: none;
}

#helpOverlay {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 700px;
  background: rgba(0, 0, 0, 0.95);
  border: 2px solid lime;
  color: lime;
  padding: 20px;
  overflow-y: auto;
  max-height: 90%;
  
  /* Animation-related: */
  opacity: 0;
  transition: opacity 0.3s ease;
}

#helpOverlay.show {
  opacity: 1;
}



#helpOverlay h2,
#helpOverlay h3 {
  color: lime;
  margin-top: 0;
}

#helpOverlay ul {
  padding-left: 20px;
}

#helpOverlay button {
  background: black;
  border: 2px solid lime;
  color: lime;
  padding: 10px 20px;
  font-family: monospace;
  cursor: pointer;
}

#helpOverlay button:hover {
  background: lime;
  color: black;
}