.txt {
  color: #008000;
  /* font-family:
    "方正准圆 GB18030L2", "Microsoft YaHei UI", "黑体", "Simsum", "MingLiu"; */
  font-size: 20pt;
  line-height: 1.6;
  margin: 16px; /* cust margin-top to margin */
  background-color: #f0ffff;
  padding: 15px;
  border-radius: 5px;
  box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
}

tr,
td {
  text-align: left;
  padding-left: 54px;
  padding-right: 54px;
}

.c {
  color: #008000;
  font-size: 22pt;
}

.container {
  display: flex;
  align-items: flex-start; /* 防止两栏高度被强制拉齐 */
}

.sidebar {
  background-color: #e0ffff;
  font-size: 14pt;
  width: 120px; /* cust */
  flex-shrink: 0; /* 固定宽度，不被压缩 */
  /* 可选：让目录在滚动时固定 */
  position: sticky;
  /* 必须设置 top 值，否则 sticky 不会生效 */
  position: -webkit-sticky; /* 兼容 Safari */
  top: 20px; /* 距离视口顶部 20px 时开始固定 */
  /* 可选：限制最大高度，防止目录过长超出屏幕 */
  max-height: calc(100vh - 40px);
  overflow-y: auto;
  padding: 8px; /* cust */
}

.content {
  flex: 1; /* 占满剩余宽度 */
  padding-left: 20px;
  padding-right: 16px; /* cust */
}

.content h2 {
  /* cust */
  margin-top: 1em;
  margin-bottom: 1em;
}

.star {
  display: block;
  color: #008000;
  /* font-family: "方正准圆 GB18030L2", "Microsoft YaHei UI", "黑体"; */
  font-weight: bold;
  font-size: 20pt;
  padding-left: 2em; /* 整体向右推2em */
  text-align: justify;
  padding-top: 12px; /* cust */
  padding-bottom: 12px; /* cust */
}

.hidden {
  display: none;
}
.top {
  text-align: left;
  vertical-align: top;
}
.center {
  text-align: center;
}

.content ol,
.content ul {
  padding-left: 1em; /* cust */
}