.back-btn {
  position: fixed;
  top: 20px;
  left: 20px;
  z-index: 9;
  background: var(--accent);
  color: #081408;
  font-weight: 800;
  text-decoration: none;
  padding: 10px 16px;
  border-radius: 10px;
  box-shadow: 0 6px 20px rgba(5,226,5,.25);
  transition: box-shadow .2s ease, transform .2s ease;
}

.back-btn:hover {
  box-shadow: 0 8px 25px rgba(5,226,5,.45);
  transform: translateY(-2px);
}