:root{
  --main-width: 860px;
  --text-color: #222;
  --muted-color: #666;
  --line-color: #e8e8e8;
  --link-color: #0b57d0;
  --bg-soft: #f8f9fb;
}

*{
  box-sizing: border-box;
}

html{
  -webkit-text-size-adjust: 100%;
}

body{
  margin: 0;
  padding: 0 16px 40px;
  color: var(--text-color);
  background: #fff;
  font: 16px/1.85 -apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,
       "PingFang SC","Hiragino Sans GB","Microsoft YaHei",Arial,sans-serif;
  word-wrap: break-word;
}

body > *{
  max-width: var(--main-width);
  margin-left: auto;
  margin-right: auto;
}

a{
  color: var(--link-color);
  text-decoration: none;
}

a:hover{
  text-decoration: underline;
}

img{
  max-width: 100%;
  height: auto;
  border: 0;
}

.breadcrumb{
  margin: 18px auto 14px;
  color: var(--muted-color);
  font-size: 14px;
  line-height: 1.7;
}

.breadcrumb ol{
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.breadcrumb li{
  display: flex;
  align-items: center;
}

.breadcrumb li:not(:last-child)::after{
  content: ">";
  margin-left: 6px;
  color: #999;
}

h1,h2,h3{
  color: #111;
  line-height: 1.45;
  margin: 18px auto 14px;
}

h2{
  font-size: 30px;
  font-weight: 700;
}

h3{
  font-size: 22px;
  margin-top: 28px;
  padding-left: 10px;
  border-left: 4px solid #d9e6ff;
}

p{
  margin: 0 auto 16px;
  text-align: justify;
}

.publish-info{
  margin: 8px auto 16px;
  color: var(--muted-color);
  font-size: 14px;
}

.article-cover{
  margin: 10px auto 22px;
}

.article-cover img{
  display: block;
  width: 100%;
  border-radius: 10px;
  background: #f3f3f3;
}

.related-links{
  max-width: var(--main-width);
  margin: 26px auto 0;
  padding: 16px 16px 10px;
  background: var(--bg-soft);
  border: 1px solid var(--line-color);
  border-radius: 12px;
}

.related-links-title{
  margin: 0 0 12px;
  font-size: 18px;
  font-weight: 700;
  color: #111;
}

.related-links-list{
  display: grid;
  grid-template-columns: repeat(auto-fit,minmax(220px,1fr));
  gap: 10px 14px;
}

.related-links a{
  display: flex;
  align-items: center;
  gap: 6px;
  min-height: 24px;
  padding: 6px 0;
  line-height: 1.6;
}

.related-links a img{
  width: 18px;
  height: 18px;
  flex: 0 0 18px;
  object-fit: contain;
}

table{
  width: 100%;
  border-collapse: collapse;
  margin: 16px auto;
}

table,th,td{
  border: 1px solid var(--line-color);
}

th,td{
  padding: 10px 12px;
  text-align: left;
}

blockquote{
  margin: 16px auto;
  padding: 12px 14px;
  background: #fafafa;
  border-left: 4px solid #ddd;
  color: #444;
}

#backToTop{
  position: fixed;
  right: 18px;
  bottom: 24px;
  width: 42px;
  height: 42px;
  border: none;
  border-radius: 999px;
  background: #111;
  color: #fff;
  font-size: 18px;
  cursor: pointer;
  display: none;
  z-index: 9999;
  box-shadow: 0 6px 18px rgba(0,0,0,.18);
}

#backToTop.show{
  display: block;
}

@media (max-width: 768px){
  body{
    padding: 0 12px 32px;
    font-size: 15px;
    line-height: 1.8;
  }

  h2{
    font-size: 24px;
  }

  h3{
    font-size: 19px;
  }

  .related-links-list{
    grid-template-columns: 1fr;
  }
}