.dot-nav {
  display: block;
  position: fixed;
  left: 20px;
  top: 50%;
  transform: translateY(-50%);
  display: flex;
  flex-direction: column;
  z-index: 10;
}

.dot-link {
  display: block;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background-color: #333;
  margin: 10px 0;
  transition: background-color 0.3s;
}

.dot-link.active {
  background-color: #fff;
}