html,
body {
  background-color: black;
}

html,
body,
#c {
  height: 100%;
}
#c {
  width: 100%;
}

.container {
  position: fixed;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
}

.container img {
  width: 100px;
}

ul {
  position: fixed;
  z-index: 10;
  top: 90%;
  left: 50%;
  transform: translate(-50%, -50%);
}