body, h1, h2, h3, h4, h5, h6 {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
             "Helvetica Neue", Helvetica, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei",
             SimSun, sans-serif;
}
.markdown-body h1, .markdown-body h2 {
  padding-bottom: .75em;
  margin-top: 3em;
}

.doc-img {
  width: 50%;
  display: block;
  margin: 24px 0;
}