.stoixima-back-to-top-button {
  position: fixed;
  width: 50px;
  height: 50px;
  background-color: var(--btn-bg-color, #0066cc);
  color: var(--btn-text-color, #ffffff);
  border: none;
  border-radius: 50%;
  font-size: 24px;
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.3s ease, visibility 0.3s ease, transform 0.2s ease;
  z-index: 999;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
  display: flex;
  align-items: center;
  justify-content: center;
  line-height: 1;
}

.stoixima-back-to-top-button[data-position="bottom-right"] {
  bottom: 30px;
  right: 30px;
}

.stoixima-back-to-top-button[data-position="bottom-left"] {
  bottom: 30px;
  left: 30px;
}

.stoixima-back-to-top-button.visible {
  opacity: 1;
  visibility: visible;
}

.stoixima-back-to-top-button:hover {
  transform: translateY(-3px);
  box-shadow: 0 6px 16px rgba(0, 0, 0, 0.3);
}

.stoixima-back-to-top-button:active {
  transform: translateY(-1px);
}

/* Mobile responsive */
@media (max-width: 768px) {
  .stoixima-back-to-top-button {
    width: 45px;
    height: 45px;
    font-size: 20px;
  }

  .stoixima-back-to-top-button[data-position="bottom-right"] {
    bottom: 20px;
    right: 20px;
  }

  .stoixima-back-to-top-button[data-position="bottom-left"] {
    bottom: 20px;
    left: 20px;
  }
}