body{background-color: #fff;}
#topbar{position: fixed;left: 0;right: 0;background-color: #fff;border-bottom: 1px solid #ddd;z-index: 2;}
ul.nav{position: sticky;top: 66px;display: inline-block;vertical-align: top;width: 300px;height:100vh;padding: 8px 32px;border-right: 1px solid #ccc;}
.page{display: inline-block;vertical-align: top;width: calc(100% - 300px);padding: 48px;}
.page p{margin: 16px 0;line-height: 24px;}
.page img{display: block;max-width: 100%;}
b.h2{display: block;font-size: 26px;}
b.h3{display: block;font-size: 22px;}
b.h4{display: block;font-size: 18px;}
b.hr{border-bottom: 1px solid #ccc;padding-bottom: 8px;}
span.code{display: inline-block;padding: 4px 8px;margin: 0 6px;color: #db3419;background-color: #f3f5f7;border-radius: 5px;}
pre.code{padding: 16px;background-color: #333;color: #cbc3ad}
p.tip{padding: 16px;background-color: #f3f5f7;border-left: .5rem solid #42b983;}
.des{padding: 16px;margin: 16px 0;background-color: #f3f5f7;border-radius: 5px;}
.des ol{padding: 8px 32px;color: #444;line-height: 24px;}
.nav ul{padding: 8px;}
.nav li{display: block;padding: 8px;}
.nav li>a{display: block;font-size: 18px;text-decoration: none;color: #444}
.nav nav{padding: 8px;}
.nav nav a{display: block;padding: 4px;text-decoration: none;color: #000;cursor: pointer;}
.nav nav a::before{content: '# ';}
.nav .act{font-weight: bold;color: #000}
.target{position: relative;top: -70px}