@import url('https://fonts.googleapis.com/css2?family=Outfit:wght@300;400;500;600;700&family=Work+Sans:wght@300;400;500;600;700&display=swap');

:root{
  --mint:#5cc6b0;
  --sand:#d4c4a8;
  --ink:#172623;
  --paper:#f5f0e7;
  --paper-2:#ece2d2;
  --clay:#c67b5c;
  --olive:#6b7b3c;
  --line:rgba(23,38,35,.16);
  --line-soft:rgba(23,38,35,.09);
  --card:#fbf8f2;
  --soft:0 22px 46px -30px rgba(23,38,35,.55);
  --geo:"Outfit","Work Sans","PingFang SC","Hiragino Sans GB","Microsoft YaHei",system-ui,sans-serif;
  --sans:"Work Sans","PingFang SC","Hiragino Sans GB","Microsoft YaHei",system-ui,sans-serif;
}

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

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

body{
  margin:0;
  background:var(--paper);
  color:var(--ink);
  font-family:var(--sans);
  font-size:17px;
  line-height:1.78;
  letter-spacing:.01em;
  overflow-x:hidden;
}

body::before{
  content:"";
  position:fixed;
  inset:0;
  z-index:3;
  pointer-events:none;
  opacity:.55;
  background-image:radial-gradient(rgba(23,38,35,.085) .8px,transparent .8px);
  background-size:5px 5px;
}

img{display:block;max-width:100%;height:auto}

a{color:inherit}

h1,h2,h3,h4{
  font-family:var(--geo);
  line-height:1.14;
  letter-spacing:-.015em;
  margin:0 0 .55em;
}

p{margin:0 0 1em}

/* ---------- 顶栏 ---------- */
.masthead{
  position:sticky;
  top:0;
  z-index:20;
  display:grid;
  grid-template-columns:1fr auto 1fr;
  align-items:center;
  gap:14px;
  padding:10px clamp(14px,3.4vw,38px);
  background:rgba(245,240,231,.95);
  border-bottom:1px solid var(--line);
  backdrop-filter:blur(7px);
}

.masthead .rail{min-width:0}

.rail-r{
  display:flex;
  align-items:center;
  gap:10px;
  justify-self:end;
}

.mnav ul{
  display:flex;
  flex-wrap:wrap;
  gap:1px 4px;
  margin:0;
  padding:0;
  list-style:none;
}

.rail-r .mnav ul{justify-content:flex-end}

.mnav a{
  display:inline-flex;
  align-items:center;
  min-height:42px;
  padding:0 9px;
  font-size:.94rem;
  text-decoration:none;
  border-bottom:2px solid transparent;
  transition:border-color .25s ease-out,color .25s ease-out;
}

.mnav a:hover,
.mnav a:focus-visible{
  border-bottom-color:var(--mint);
  color:#0f4c41;
}

.mark{
  display:inline-flex;
  align-items:center;
  justify-content:center;
  min-height:44px;
  font-family:var(--geo);
  font-size:1.12rem;
  font-weight:700;
  letter-spacing:.22em;
  text-decoration:none;
  text-align:center;
  white-space:nowrap;
}

.mark-img{height:32px;width:auto}

.seek{
  display:flex;
  align-items:center;
  gap:6px;
  margin-left:6px;
}

.seek input{
  width:120px;
  height:40px;
  padding:0 10px;
  border:1px solid var(--line);
  border-radius:0;
  background:#fdfaf4;
  font-family:var(--sans);
  font-size:16px;
  color:var(--ink);
}

.seek input:focus{outline:2px solid var(--mint);outline-offset:1px}

.seek button{
  height:40px;
  padding:0 13px;
  border:0;
  border-radius:0;
  background:var(--ink);
  color:#f5f0e7;
  font-family:var(--sans);
  font-size:.86rem;
  letter-spacing:.1em;
  cursor:pointer;
}

.seek button:hover{background:#0d3a32}

/* ---------- 首屏 ---------- */
.stage{
  position:relative;
  isolation:isolate;
  display:grid;
  align-content:end;
  min-height:100svh;
  padding:150px clamp(16px,4vw,44px) clamp(56px,9vh,110px);
  overflow:hidden;
  color:#f8f4ea;
  background:linear-gradient(158deg,#28403a 0%,#172623 58%,#2f3b2c 100%);
  clip-path:polygon(0 0,100% 0,100% 92%,0 100%);
}

.stage-art{
  position:absolute;
  inset:0;
  margin:0;
  z-index:0;
}

.stage-art::after{
  content:"";
  position:absolute;
  inset:0;
  background:linear-gradient(178deg,rgba(23,38,35,.42) 0%,rgba(23,38,35,.52) 42%,rgba(23,38,35,.88) 100%);
}

.stage-img{
  position:absolute;
  top:-9%;
  left:0;
  width:100%;
  height:118%;
  object-fit:cover;
  opacity:0;
  transition:opacity 1.1s ease-out;
  will-change:transform;
}

.stage-img.on{opacity:1}

.stage-badge{
  position:absolute;
  top:clamp(22px,7vw,64px);
  right:clamp(16px,4vw,52px);
  z-index:2;
  margin:0;
  padding:7px 13px 7px 15px;
  background:var(--mint);
  color:var(--ink);
  font-family:var(--geo);
  font-size:.76rem;
  font-weight:600;
  letter-spacing:.32em;
}

.stage-copy{
  position:relative;
  z-index:2;
  width:100%;
  max-width:1180px;
  margin:0 auto;
  text-align:right;
}

.stage-copy h1{
  margin:0 0 .38em;
  font-size:clamp(2rem,6.2vw,4.5rem);
  font-weight:600;
  letter-spacing:-.03em;
  text-wrap:balance;
}

.stage-sub{
  margin:0 0 0 auto;
  max-width:52ch;
  font-size:clamp(.96rem,1.5vw,1.1rem);
  line-height:1.7;
  color:rgba(248,244,234,.84);
}

/* ---------- 主体分区 ---------- */
.spread{
  display:grid;
  grid-template-columns:minmax(0,1fr) 300px;
  align-items:start;
  gap:clamp(24px,3.6vw,52px);
  max-width:1180px;
  margin:0 auto;
  padding:clamp(34px,5.4vw,68px) clamp(14px,4vw,44px) 0;
}

.prose{min-width:0}

.prose section,
.prose > article{
  scroll-margin-top:100px;
}

.prose section{
  margin:0 0 26px;
  padding:clamp(20px,3vw,38px);
  background:var(--card);
  border-top:3px solid var(--sand);
  box-shadow:var(--soft);
}

.prose section:first-child{border-top-color:var(--mint)}

.prose section[id]{scroll-margin-top:100px}

.prose h2{
  font-size:clamp(1.36rem,2.6vw,1.95rem);
  margin:0 0 .35em;
}

.prose h3{
  font-size:clamp(1.1rem,1.9vw,1.32rem);
  margin:1.4em 0 .4em;
  color:#20423a;
}

.prose h2 + hr,
.prose h3 + hr{
  width:66px;
  margin:0 0 18px;
  border:0;
  border-top:2px solid var(--mint);
}

.prose p{margin:0 0 1.05em}

.prose a{
  color:#2c7566;
  text-decoration:underline;
  text-underline-offset:3px;
}

.prose ul,.prose ol{padding-left:1.35em;margin:0 0 1.1em}

.prose li{margin:0 0 .4em}

.prose figure{margin:22px 0}

.prose figure img{box-shadow:var(--soft)}

.prose figcaption{
  padding-top:8px;
  font-size:.86rem;
  color:#5a6a62;
}

.prose blockquote{
  margin:22px 0;
  padding:14px 20px;
  border-left:4px solid var(--clay);
  background:#f4ece0;
  font-style:normal;
}

.prose table{
  width:100%;
  margin:20px 0;
  border-collapse:collapse;
  font-size:.95rem;
}

.prose th,.prose td{
  border:1px solid var(--line);
  padding:9px 11px;
  text-align:left;
}

.prose th{background:var(--paper-2)}

/* ---------- 侧栏 ---------- */
.side{
  position:sticky;
  top:96px;
  align-self:start;
  padding:18px 18px 22px;
  background:var(--paper-2);
  border-left:3px solid var(--mint);
  box-shadow:var(--soft);
}

.side-h{
  margin:0 0 9px;
  font-size:.94rem;
  font-weight:600;
  letter-spacing:.28em;
}

.side hr{
  margin:0 0 12px;
  border:0;
  border-top:1px solid var(--line);
}

.side-list{
  margin:0;
  padding:0;
  list-style:none;
  counter-reset:side;
  font-size:.94rem;
}

.side-list li{
  counter-increment:side;
  border-bottom:1px dashed var(--line-soft);
}

.side-list li:last-child{border-bottom:0}

.side-list a{
  display:flex;
  align-items:center;
  gap:10px;
  min-height:42px;
  padding:4px 0;
  text-decoration:none;
}

.side-list a::before{
  content:counter(side,decimal-leading-zero);
  font-family:var(--geo);
  font-size:.76rem;
  letter-spacing:.08em;
  color:var(--clay);
}

.side-list a:hover{color:#0f4c41}

/* ---------- 回到顶部 ---------- */
.to-top{
  max-width:1180px;
  margin:44px auto 0;
  padding:0 clamp(14px,4vw,44px);
  text-align:center;
}

.to-top a{
  display:inline-block;
  padding:13px 26px;
  background:var(--ink);
  color:#f5f0e7;
  font-size:.88rem;
  letter-spacing:.16em;
  text-decoration:none;
}

.to-top a:hover{background:#0d3a32}

/* ---------- 页脚 ---------- */
.foot{
  display:grid;
  grid-template-columns:1.35fr 1fr auto;
  align-items:start;
  gap:clamp(20px,3vw,40px);
  margin-top:clamp(48px,7vw,84px);
  padding:clamp(34px,5vw,56px) clamp(14px,4vw,44px) 26px;
  background:var(--ink);
  color:#e9e1d1;
}

.foot-brand{
  margin:0;
  font-family:var(--geo);
  font-size:clamp(1.9rem,6.4vw,4rem);
  font-weight:700;
  line-height:.92;
  letter-spacing:-.03em;
  color:#f6f1e7;
}

.foot-nav{
  display:flex;
  flex-wrap:wrap;
  gap:2px 14px;
  margin:0;
  font-size:.9rem;
}

.foot-nav a{
  display:inline-flex;
  align-items:center;
  min-height:40px;
  padding:2px 0;
  color:#cdc4b4;
  text-decoration:none;
}

.foot-nav a:hover{color:var(--mint)}

.foot-copy{
  align-self:end;
  font-size:.8rem;
  line-height:1.6;
  text-align:center;
  color:#9d9customized;
  color:#9d968a;
}

/* ---------- 动效 ---------- */
.rv{
  opacity:0;
  transform:translateY(16px);
  transition:opacity .7s cubic-bezier(.2,.7,.3,1),transform .7s cubic-bezier(.2,.7,.3,1);
}

.rv.in{
  opacity:1;
  transform:none;
}

/* ---------- 中屏 ---------- */
@media (max-width:1080px){
  .mnav a{padding:0 7px;font-size:.9rem}
  .seek input{width:104px}
  .spread{grid-template-columns:minmax(0,1fr) 262px}
}

/* ---------- 窄屏 ---------- */
@media (max-width:900px){
  body{font-size:16px}

  .masthead{
    position:static;
    grid-template-columns:1fr;
    gap:4px;
    padding:8px 12px 10px;
  }

  .masthead .rail{width:100%}

  .rail-l,.rail-r{justify-self:stretch;display:block}

  .mnav ul{
    flex-wrap:nowrap;
    overflow-x:auto;
    gap:0 2px;
    padding-bottom:2px;
  }

  .rail-r .mnav ul{justify-content:flex-start}

  .mnav a{min-height:42px;padding:0 9px;white-space:nowrap}

  .mark{
    order:-1;
    justify-content:center;
    min-height:40px;
    letter-spacing:.26em;
    font-size:1.02rem;
  }

  .seek{
    margin:6px 0 0;
  }

  .seek input{flex:1 1 auto;width:auto;min-width:0;height:42px}

  .seek button{height:42px}

  .stage{
    min-height:74svh;
    padding:74px 18px 46px;
    clip-path:polygon(0 0,100% 0,100% 94%,0 100%);
  }

  .stage-badge{top:20px;right:16px}

  .stage-copy h1{font-size:clamp(1.9rem,8.4vw,2.7rem)}

  .stage-sub{max-width:100%;font-size:.98rem}

  .spread{
    grid-template-columns:minmax(0,1fr);
    gap:34px;
    padding:30px 14px 0;
  }

  .side{
    position:static;
    order:2;
  }

  .foot{
    grid-template-columns:1fr;
    justify-items:center;
    text-align:center;
    gap:16px;
  }

  .foot-nav{justify-content:center}

  .foot-copy{align-self:center}
}

@media (max-width:430px){
  .prose section{padding:18px 15px}
  .to-top a{padding:13px 20px}
}

@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  .stage-img,.rv{transition:none}
  .rv{opacity:1;transform:none}
}

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