@media (max-width: 768px) {
  .mobile-menu-btn {
    display: block;
  }

  .nav-links {
    display: none;
  }

  #back-to-top {
    display: block;
  }
}

#back-to-top {
  display: none;
  position: fixed;
  bottom: 40px;
  right: 40px;
  background-color: #2563eb;
  color: #ffffff;
  border: none;
  border-radius: 50%;
  padding: 10px 15px;
  cursor: pointer;
  box-shadow: 0 2px 5px rgba(0, 0, 0, 0.2);
  z-index: 1000;
  transition: background-color 0.3s ease, transform 0.3s ease;
}

#back-to-top:hover {
  background-color: #1d4ed8;
  transform: translateY(-2px);
}

.mobile-menu.open {
  display: flex;
}