body { overflow-x: hidden; }
.sidebar {
  position: fixed; top: 20; left: 0;
  width: 220px; height: 100vh;
  background: #f8f9fa; padding: 1rem;
}
.sidebar .nav-link.active {
  background-color: #0d6efd;
  color: #fff;
}
.main-area {
  margin-left: 240px; padding: 1rem;
}
.content {
  display: none; /* 默认隐藏 */
}
.content.active {
  display: block;
}
.base-footer{
  position:fixed; bottom: 0;
  align-items: center; justify-content: center;
  text-align: center;
}