/* 回到顶部按钮样式 */
.back-to-top {
  position: fixed;
  bottom: 20px;
  right: 20px;
  width: 40px;
  height: 40px;
  background-color: var(--primary-color, #9A2827);
  color: white;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transition: all 0.3s ease;
  z-index: 40;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.2);
}

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

/* 移动端样式优化 */
@media (max-width: 768px) {
  .back-to-top {
    bottom: 60px; /* 增加距离底部的距离，使按钮更容易操作 */
    right: 15px;
    width: 36px;
    height: 36px;
  }
}