#sidebar-toggle {
  position: fixed;
  top: 50%;
  left: 0; /* on the screen's left edge */
  transform: translateY(-50%);
  background-color: white;
  border-radius: 50%;
  width: 30px;
  height: 30px;
  font-size: 0.8rem;
  color: #003366;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 0 6px rgba(0,0,0,0.15);
  cursor: pointer;
  z-index: 9999;
  transition: left 0.3s ease;
}

#sidebar-toggle:hover {
  background-color: #f1f1f1;
}

#sidebar-toggle i.rotate {
  transform: rotate(180deg);
}