body {
  background: black;
  margin: 0;
}

nav {
  position: sticky;
  top: 0;
  background: #222;
  color: rgb(255, 255, 255);
  padding: 10px;
  text-align: center;
 z-index: 10;  /* This is what makes it stay on top Edit: I fixed it Edit: IT DOESNT WORK AGAIN */
}

.image-container {
  position: relative;
  display: block;
}

img {
  height: 2000px;
  width: 750px;
  display: block;
  margin: 0 auto;
}

.centered-text {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  color: rgb(255, 255, 255);
  font-size: 24px;
}

footer {
  position: relative;
  color: white;
  padding: 10px;
  text-align: left;
}
.back-to-top {
  position: fixed;
  bottom: 10px;
  right: 10px;
  color: #ffffff;
  border-radius: 5px;
  z-index: 20;
}