body {
  background: #f6f5fb;
}
.box-1 {
  background: url('../img/banner1.jpg') no-repeat;
  background-size: 100% 100%;
  min-height: 20rem;
}
.ml-1 {
  margin-left: 0.25rem !important;
}
.ml-2 {
  margin-left: 0.5rem !important;
}
.ml-3 {
  margin-left: 1rem !important;
}
.ml-4 {
  margin-left: 1.5rem !important;
}
.ml-5 {
  margin-left: 3rem !important;
}
.mt-1 {
  margin-top: 0.25rem !important;
}
.mt-2 {
  margin-top: 0.5rem !important;
}
.mt-3 {
  margin-top: 1rem !important;
}
.mt-4 {
  margin-top: 1.5rem !important;
}
.mt-5 {
  margin-top: 3rem !important;
}
.mr-1 {
  margin-right: 0.25rem !important;
}
.mr-2 {
  margin-right: 0.5rem !important;
}
.mr-3 {
  margin-right: 1rem !important;
}
.mr-4 {
  margin-right: 1.5rem !important;
}
.mr-5 {
  margin-right: 3rem !important;
}
.fs-7 {
  font-size: 0.75rem !important;
}
.fs-8 {
  font-size: 0.5rem !important;
}

/* 头部高度为 60px */
.sticky-top {
  height: 6rem;
}

/* 为所有锚点目标添加偏移 */
:target::before {
  content: '';
  display: block;
  height: 6rem; /* 与头部高度相同 */
  margin-top: -6rem; /* 负值抵消偏移 */
  visibility: hidden;
}

/* 下拉菜单容器 */
.dropdown-menu {
  display: block;
  opacity: 0;
  transform: translateY(-60px);
  transition: all 0.5s ease;
  pointer-events: none;
}

/* 展开状态 */
.dropdown-menu.show {
  opacity: 1;
  transform: translateY(0);
  pointer-events: auto;
}