@import url('https://fonts.googleapis.com/css2?family=Calistoga:ital@0;1&family=Inter:wght@300;400;500;600;700&family=JetBrains+Mono:wght@400;500&display=swap');

:root{
  --paper:#fafaf8;
  --mid:#4a4a4a;
  --ink:#1a1a1a;
  --rule:2px solid var(--ink);
  --dash:2px dashed var(--mid);
  --rad:10px;
  --noise:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='160' height='160'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.92' numOctaves='4' stitchTiles='stitch'/%3E%3CfeColorMatrix type='saturate' values='0'/%3E%3C/filter%3E%3Crect width='160' height='160' filter='url(%23n)' opacity='0.13'/%3E%3C/svg%3E");
}

*,*::before,*::after{box-sizing:border-box}

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

body{
  margin:0;
  background-color:var(--paper);
  background-image:var(--noise);
  color:var(--ink);
  font-family:"Inter",system-ui,-apple-system,"PingFang SC","Hiragino Sans GB","Microsoft YaHei",sans-serif;
  font-size:1rem;
  font-weight:400;
  line-height:1.78;
}

body > script{display:none}
img{max-width:100%;height:auto}
a{color:var(--ink)}
p{margin:0 0 1.1rem}

/* 顶部细条 */
.announce{
  background:var(--ink);
  color:var(--paper);
  padding:.42rem 1rem;
  text-align:center;
  letter-spacing:.08em;
  overflow:hidden;
}
.announce span{
  display:block;
  font-size:1rem;
  white-space:nowrap;
  overflow:hidden;
  text-overflow:ellipsis;
}

/* 报头 */
.masthead{
  background:var(--paper);
  border-bottom:var(--rule);
  padding:.45rem clamp(.85rem,4vw,2.25rem);
}
.m-nav ul{
  list-style:none;
  margin:0;
  padding:0;
  display:flex;
  justify-content:center;
  gap:.4rem;
  flex-wrap:wrap;
}
.m-nav li{display:none}
.m-nav li.m-brand{display:block}
.m-brand a{
  display:inline-block;
  padding:.4rem .3rem;
  font-family:"Calistoga","Songti SC",Georgia,"Noto Serif SC",serif;
  font-size:1.45rem;
  line-height:1.2;
  letter-spacing:-.01em;
  text-decoration:none;
  color:var(--ink);
}

/* 锚点轨 */
.rail{
  position:sticky;
  top:0;
  z-index:40;
  background:var(--paper);
  border-bottom:var(--rule);
}
.pillnav ul{
  list-style:none;
  margin:0;
  padding:.4rem clamp(.6rem,3vw,1rem);
  display:flex;
  gap:.45rem;
  overflow-x:auto;
  scrollbar-width:none;
}
.pillnav ul::-webkit-scrollbar{display:none}
.pillnav a{
  display:inline-flex;
  align-items:center;
  min-height:44px;
  padding:0 .85rem;
  border:var(--rule);
  border-radius:999px;
  background:var(--paper);
  color:var(--ink);
  font-size:1rem;
  text-decoration:none;
  white-space:nowrap;
}
.pillnav li:nth-child(odd) a{transform:rotate(-.7deg)}
.pillnav li:nth-child(even) a{transform:rotate(.6deg)}
.pillnav a:hover,.pillnav a:focus-visible{background:var(--ink);color:var(--paper)}

/* 主区 */
.doc{
  max-width:1080px;
  margin-inline:auto;
  padding:0 clamp(1rem,4vw,2.5rem);
}

.hero{
  position:relative;
  overflow:hidden;
  display:flex;
  flex-direction:column;
  justify-content:flex-start;
  align-items:flex-end;
  text-align:right;
  padding:1.6rem 0 4.6rem;
  min-height:auto;
}
.hero::before{
  content:"";
  position:absolute;
  left:-9%;
  right:-9%;
  bottom:0;
  height:78px;
  background:var(--ink);
  transform:rotate(-1.4deg);
  transform-origin:0 100%;
  z-index:0;
}
.hero::after{
  content:"";
  position:absolute;
  top:.9rem;
  left:0;
  width:104px;
  height:24px;
  background:rgba(74,74,74,.16);
  border-left:2px dashed rgba(26,26,26,.4);
  border-right:2px dashed rgba(26,26,26,.4);
  transform:rotate(-2.6deg);
  z-index:0;
}
.hero h1{
  position:relative;
  z-index:1;
  margin:0 0 1rem;
  font-family:"Calistoga","Songti SC",Georgia,"Noto Serif SC",serif;
  font-size:clamp(2.05rem,8.4vw,5.2rem);
  line-height:1.06;
  letter-spacing:-.02em;
  text-wrap:balance;
}
.hero .lead{
  position:relative;
  z-index:1;
  margin:0;
  max-width:48ch;
  color:var(--mid);
  font-size:clamp(1rem,2.2vw,1.12rem);
}

/* 正文 */
.content{
  max-width:72ch;
  margin:clamp(2rem,5vw,3.2rem) auto clamp(2.5rem,6vw,4rem);
  padding:0;
}

.content > section{
  position:relative;
  margin:0 0 3rem;
  padding-top:1.5rem;
  border-top:var(--dash);
  scroll-margin-top:84px;
}
.content > section:first-of-type{border-top:0;padding-top:0}
.content > section:nth-of-type(odd){transform:rotate(-.12deg)}
.content > section:nth-of-type(even){transform:rotate(.12deg)}

.content h2{
  margin:0 0 1rem;
  font-family:"Calistoga","Songti SC",Georgia,"Noto Serif SC",serif;
  font-size:clamp(1.65rem,4.8vw,2.6rem);
  line-height:1.16;
  letter-spacing:-.015em;
  text-align:right;
  transform:rotate(-.6deg);
}
.content h2::after{
  content:"";
  display:block;
  width:34%;
  height:3px;
  margin:.55rem 0 0 auto;
  background:var(--ink);
  transform:rotate(.9deg);
}
.content h2 + p{margin-top:0}
.content h3{
  margin:1.8rem 0 .7rem;
  font-size:1.22rem;
  line-height:1.45;
  letter-spacing:.01em;
}
.content h3::before{content:"";display:inline-block;width:.7rem;height:.7rem;margin-right:.5rem;border:var(--rule);transform:rotate(12deg) translateY(-1px)}
.content p{text-align:justify;text-justify:inter-ideograph}
.content .subtitle,.content .subhead,.content .desc,.content .lead{color:var(--mid)}
.content ul,.content ol{margin:0 0 1.2rem;padding-left:1.35rem}
.content li{margin:.35rem 0}
.content li::marker{color:var(--mid)}
.content a{text-decoration:underline;text-decoration-style:dashed;text-decoration-thickness:2px;text-underline-offset:3px}
.content a:hover{background:var(--ink);color:var(--paper);text-decoration-style:solid}
.content img{
  display:block;
  margin:1.4rem 0;
  padding:6px;
  background:#fff;
  border:var(--rule);
  border-radius:var(--rad);
}
.content figure{margin:1.4rem 0}
.content figcaption{margin-top:.4rem;color:var(--mid);font-size:1rem;text-align:right}
.content blockquote{
  margin:1.4rem 0;
  padding:.9rem 1.1rem;
  background:#fff;
  border:var(--rule);
  border-left-width:9px;
  border-radius:var(--rad);
  transform:rotate(-.35deg);
}
.content blockquote p:last-child{margin-bottom:0}
.content hr{border:0;border-top:var(--dash);margin:2.2rem 0}
.content table{display:block;overflow-x:auto;border-collapse:collapse;font-size:1rem;margin:0 0 1.3rem}
.content th,.content td{border:2px solid var(--ink);padding:.5rem .7rem;text-align:left}
.content th{background:#fff;font-weight:600}
.content code{font-family:"JetBrains Mono",ui-monospace,monospace;font-size:.92em;background:#fff;border:1px solid var(--mid);border-radius:4px;padding:0 .28em}
.content pre{overflow-x:auto;background:#fff;border:var(--rule);border-radius:var(--rad);padding:.9rem}

/* 页脚 */
.foot{
  margin-top:2rem;
  padding:clamp(1.5rem,5vw,2.6rem) clamp(1rem,4vw,2.25rem) 1.4rem;
  border-top:var(--rule);
  display:grid;
  grid-template-columns:minmax(0,1fr);
  gap:.9rem;
}
.f-sec{
  border:var(--rule);
  border-radius:var(--rad);
  background:#fff;
  padding:.9rem 1rem;
}
.f-sec:nth-child(1){transform:rotate(-.45deg)}
.f-sec:nth-child(2){transform:rotate(.35deg)}
.f-sec:nth-child(3){transform:rotate(-.25deg)}
.f-sec h2{
  margin:0;
  font-family:"Calistoga","Songti SC",Georgia,"Noto Serif SC",serif;
  font-size:1.16rem;
  line-height:1.4;
}
.f-sec .subtitle{margin:.1rem 0 .7rem;color:var(--mid);font-size:1rem}
.f-logo{
  margin:0 0 .8rem;
  font-family:"Calistoga","Songti SC",Georgia,"Noto Serif SC",serif;
  font-size:1.4rem;
  line-height:1.3;
}
.f-top{
  display:inline-flex;
  align-items:center;
  min-height:44px;
  padding:0 .9rem;
  border:var(--rule);
  border-radius:999px;
  text-decoration:none;
  font-size:1rem;
}
.f-top:hover{background:var(--ink);color:var(--paper)}
.f-list{list-style:none;margin:0;padding:0;display:flex;flex-wrap:wrap;gap:.4rem}
.f-list a{
  display:inline-flex;
  align-items:center;
  min-height:42px;
  padding:0 .7rem;
  border:2px solid var(--mid);
  border-radius:999px;
  color:var(--ink);
  font-size:1rem;
  text-decoration:none;
}
.f-list a:hover{border-color:var(--ink);background:var(--ink);color:var(--paper)}
.f-form{display:flex;flex-wrap:wrap;gap:.5rem}
.f-form input{
  flex:1 1 9ch;
  min-width:0;
  min-height:44px;
  padding:0 .8rem;
  border:var(--rule);
  border-radius:var(--rad);
  background:var(--paper);
  color:var(--ink);
  font:inherit;
  font-size:1rem;
}
.f-form button{
  min-height:44px;
  padding:0 1.1rem;
  border:var(--rule);
  border-radius:999px;
  background:var(--ink);
  color:var(--paper);
  font:inherit;
  font-size:1rem;
  cursor:pointer;
}
.f-form button:hover{background:var(--mid);border-color:var(--mid)}
.f-form input:focus-visible,.f-form button:focus-visible,.f-top:focus-visible,.f-list a:focus-visible,.pillnav a:focus-visible,.m-nav a:focus-visible{outline:3px dashed var(--mid);outline-offset:2px}
.f-base{text-align:center;border-style:dashed}
.f-base p{margin:0;font-size:1rem;color:var(--mid);letter-spacing:.04em}

/* 揭示 */
.rv{opacity:0;transform:translateY(16px) rotate(-.3deg)}
.rv.in{
  opacity:1;
  transform:none;
  transition:opacity .3s steps(3,end),transform .3s steps(3,end);
  transition-delay:calc(var(--i,0) * 55ms);
}

/* 窄屏之后的横向版式 */
@media (min-width:640px){
  .foot{grid-template-columns:repeat(2,minmax(0,1fr))}
  .f-base{grid-column:1 / -1}
  .hero{padding-bottom:6rem}
}

@media (min-width:1040px){
  body{display:grid;grid-template-columns:206px minmax(0,1fr);grid-template-rows:auto auto 1fr auto;column-gap:clamp(1rem,2.5vw,2.2rem)}
  .announce{grid-column:1 / -1;grid-row:1}
  .masthead{grid-column:1 / -1;grid-row:2;padding-block:.6rem}
  .m-nav ul{display:grid;grid-template-columns:repeat(3,1fr) auto repeat(4,1fr);align-items:center;width:100%;gap:.25rem}
  .m-nav li{display:block;justify-self:start}
  .m-nav li:nth-child(n+5){justify-self:end}
  .m-nav li.m-brand{justify-self:center}
  .m-nav a{
    display:inline-flex;
    align-items:center;
    min-height:44px;
    padding:0 .7rem;
    color:var(--mid);
    font-size:1rem;
    text-decoration:none;
    border-bottom:2px solid transparent;
  }
  .m-nav a:hover{color:var(--ink);border-bottom-color:var(--ink)}

  .rail{
    grid-column:1;
    grid-row:3;
    align-self:start;
    top:0;
    border-bottom:0;
    border-right:var(--rule);
    padding:1.2rem .6rem 2rem;
  }
  .pillnav ul{flex-direction:column;overflow:visible;padding:0;gap:.5rem}
  .pillnav a{width:100%;justify-content:flex-start}

  .doc{grid-column:2;grid-row:3;width:100%}
  .foot{grid-column:1 / -1;grid-row:4}

  .hero{min-height:62vh;justify-content:flex-end;padding-top:3rem;padding-bottom:7rem}
  .hero::before{height:96px}

  .foot{grid-template-columns:repeat(4,minmax(0,1fr));gap:1.1rem}
  .f-brand{grid-column:span 2;display:flex;flex-direction:column;justify-content:space-between;gap:1rem}
  .f-base{grid-column:1 / -1}
}

@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  .rv{opacity:1 !important;transform:none !important;transition:none !important}
  .content > article,.pillnav li a,.f-sec{transform:none !important}
}

button[aria-expanded]{min-width:44px;min-height:44px}