/* 返回顶部按钮 */
.back-to-top {
  position: fixed;
  bottom: 30px;
  right: 30px;
  background-color: var(--primary-color);
  color: var(--white);
  border: none;
  width: 50px;
  height: 50px;
  border-radius: 50%;
  display: flex;
  justify-content: center;
  align-items: center;
  cursor: pointer;
  box-shadow: 0 4px 12px rgba(1, 78, 254, 0.3);
  transition: var(--transition);
  opacity: 0;
  visibility: hidden;
  z-index: 999;
}

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

.back-to-top:hover {
  transform: translateY(-5px);
  background-color: #0045e0;
  box-shadow: 0 6px 16px rgba(1, 78, 254, 0.4);
}

/* 导航栏滚动效果 */
.navbar-scrolled {
  background-color: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(10px);
}