.btn {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  width: 56px;
  height: 56px;
  border-radius: 50%;
  border: none;
  background: #466aff;
  color: #fff;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 4px 16px rgba(70, 106, 255, 0.4);
  z-index: 1000;
  transition: transform 0.2s ease, box-shadow 0.2s ease, background 0.2s ease;
}

.btn:hover {
  transform: scale(1.08);
  box-shadow: 0 6px 24px rgba(70, 106, 255, 0.5);
}

.btnOpen {
  background: #666;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.2);
}

.btnOpen:hover {
  background: #555;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
}

[data-theme='dark'] .btn {
  background: #466aff;
}

[data-theme='dark'] .btnOpen {
  background: #555;
}

@media (max-width: 768px) {
  .btn {
    bottom: 1.2rem;
    right: 1.2rem;
    width: 48px;
    height: 48px;
  }
}
