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

:root{
  --paper:#fdfbf7;
  --paper-2:#f5f5f5;
  --ink:#1a1a1a;
  --line:#e0e0e0;
  --muted:#5c5c58;
  --r:18px;
  --wrap:1140px;
  --pad:clamp(14px,4vw,36px);
}

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

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

body{
  margin:0;
  background:var(--paper);
  color:var(--ink);
  font-family:'Rubik','Nunito Sans','PingFang SC','Hiragino Sans GB','Microsoft YaHei',system-ui,sans-serif;
  font-size:17px;
  line-height:1.75;
  -webkit-font-smoothing:antialiased;
}

body::after{
  content:"";
  position:fixed;
  inset:0;
  z-index:2;
  pointer-events:none;
  opacity:.34;
  mix-blend-mode:multiply;
  background-image:url("data:image/svg+xml;utf8,%3Csvg xmlns='http://www.w3.org/2000/svg' width='160' height='160'%3E%3Cfilter id='g'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.85' numOctaves='3' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='160' height='160' filter='url(%23g)' opacity='0.3'/%3E%3C/svg%3E");
}

a{color:inherit}
img{max-width:100%;display:block}
p{margin:0 0 1em}
ul,ol{margin:0 0 1.1em;padding-left:1.3em}
li{margin:.35em 0}
strong{font-weight:600}

h1,h2,h3,h4{
  margin:0 0 .55em;
  font-family:'Rubik','Nunito Sans','PingFang SC',sans-serif;
  font-weight:600;
  line-height:1.3;
  letter-spacing:-.012em;
}

/* ---------- 顶部 ---------- */
.site-head{
  position:sticky;
  top:0;
  z-index:20;
  display:flex;
  align-items:center;
  gap:14px;
  padding:9px var(--pad);
  background:rgba(253,251,247,.94);
  border-bottom:1px solid var(--line);
  backdrop-filter:blur(7px);
  -webkit-backdrop-filter:blur(7px);
}

.brand{
  display:inline-flex;
  align-items:center;
  gap:9px;
  min-height:44px;
  text-decoration:none;
  font-weight:600;
  letter-spacing:.01em;
  white-space:nowrap;
}

.brand-seal{
  display:inline-grid;
  place-items:center;
  width:32px;
  height:32px;
  border:1px solid var(--ink);
  border-radius:10px;
  background:var(--paper);
  font-size:15px;
  font-weight:600;
  line-height:1;
}

.brand-name{font-size:16px}

.quick-nav{
  flex:1 1 auto;
  min-width:0;
}

.quick-nav p{
  display:flex;
  gap:2px;
  margin:0;
  overflow-x:auto;
  scrollbar-width:none;
  -ms-overflow-style:none;
}

.quick-nav p::-webkit-scrollbar{display:none}

.quick-nav a{
  display:inline-flex;
  align-items:center;
  gap:6px;
  min-height:44px;
  padding:10px 11px;
  border:1px solid transparent;
  border-radius:999px;
  font-size:16px;
  line-height:1.2;
  text-decoration:none;
  white-space:nowrap;
}

.quick-nav a:hover{border-color:var(--line);background:var(--paper-2)}

.nav-glyph{
  width:11px;
  height:11px;
  flex:0 0 auto;
  color:var(--muted);
}

.head-action{
  display:inline-flex;
  align-items:center;
  min-height:44px;
  padding:10px 16px;
  border:1px solid var(--ink);
  border-radius:999px;
  background:var(--ink);
  color:var(--paper);
  font-size:16px;
  text-decoration:none;
  white-space:nowrap;
}

/* ---------- 首屏 ---------- */
.hero{
  display:grid;
  grid-template-columns:1.02fr .98fr;
  align-items:center;
  gap:clamp(20px,4.5vw,56px);
  min-height:100vh;
  min-height:100svh;
  padding:clamp(24px,5vw,60px) var(--pad);
  border-bottom:1px solid var(--line);
}

.hero-plate{
  position:relative;
  overflow:hidden;
  aspect-ratio:4/5;
  border:1px solid var(--line);
  border-radius:var(--r);
  background:var(--paper-2);
  box-shadow:0 1px 0 rgba(26,26,26,.05);
}

.hero-img{
  width:100%;
  height:100%;
  object-fit:cover;
  transform:translate3d(0,0,0) scale(1.06);
  will-change:transform;
}

.hero-plate.is-empty{
  display:grid;
  place-content:center;
  justify-items:center;
  gap:10px;
  background:var(--paper-2);
}

.plate-mark{
  display:grid;
  place-items:center;
  width:74px;
  height:74px;
  border:1px solid var(--ink);
  border-radius:20px;
  font-size:32px;
  font-weight:600;
}

.plate-note{
  font-size:15px;
  letter-spacing:.16em;
  color:var(--muted);
}

.hero-copy{text-align:center}

.hero-badge{
  display:inline-flex;
  align-items:center;
  min-height:34px;
  margin:0 0 16px;
  padding:5px 15px;
  border:1px solid var(--ink);
  border-radius:999px;
  background:rgba(255,255,255,.66);
  font-size:15px;
  letter-spacing:.08em;
  backdrop-filter:blur(8px);
  -webkit-backdrop-filter:blur(8px);
}

.hero h1{
  font-size:clamp(30px,4.2vw,52px);
  margin:0 0 14px;
}

.hero-sub{
  max-width:34em;
  margin:0 auto 22px;
  color:var(--muted);
  font-size:17px;
}

.hero-actions{
  display:flex;
  flex-wrap:wrap;
  gap:10px;
  justify-content:center;
  margin:0 0 20px;
}

.btn{
  display:inline-flex;
  align-items:center;
  justify-content:center;
  min-height:46px;
  padding:12px 22px;
  border:1px solid var(--ink);
  border-radius:999px;
  font-size:16px;
  text-decoration:none;
}

.btn-solid{background:var(--ink);color:var(--paper)}
.btn-line{background:rgba(255,255,255,.6);color:var(--ink)}
.btn-line:hover{background:var(--paper-2)}

.hero-facts{
  display:flex;
  flex-wrap:wrap;
  gap:8px 18px;
  justify-content:center;
  margin:0;
  font-size:15px;
  color:var(--muted);
}

.hero-facts span{
  display:inline-flex;
  align-items:center;
  gap:7px;
}

.hero-facts span::before{
  content:"";
  width:6px;
  height:6px;
  border:1px solid var(--muted);
  border-radius:2px;
}

/* ---------- 主体 ---------- */
main{padding:clamp(26px,4vw,54px) var(--pad) clamp(40px,6vw,74px)}

.wrap{
  display:grid;
  grid-template-columns:250px minmax(0,1fr);
  align-items:start;
  gap:clamp(20px,3.4vw,44px);
  max-width:var(--wrap);
  margin:0 auto;
}

.side{
  position:sticky;
  top:76px;
  padding:18px;
  border:1px solid rgba(26,26,26,.1);
  border-radius:var(--r);
  background:rgba(255,255,255,.62);
  box-shadow:0 1px 0 rgba(26,26,26,.04);
  backdrop-filter:blur(10px);
  -webkit-backdrop-filter:blur(10px);
}

.side h2{
  font-size:17px;
  margin:0 0 8px;
  letter-spacing:.02em;
}

.side-hint{
  margin:0 0 12px;
  font-size:15px;
  color:var(--muted);
}

.side-list{display:grid;gap:2px;margin:0 0 12px}

.side-list a{
  display:flex;
  align-items:center;
  min-height:40px;
  padding:8px 10px;
  border:1px solid transparent;
  border-radius:12px;
  font-size:16px;
  text-decoration:none;
}

.side-list a:hover{border-color:var(--line);background:var(--paper-2)}

.side-note{
  margin:0;
  padding-top:12px;
  border-top:1px solid var(--line);
  font-size:15px;
  color:var(--muted);
}

.body-col{min-width:0}

.paper-article{max-width:72ch}

.lede{
  padding:20px 22px;
  border:1px solid rgba(26,26,26,.1);
  border-radius:var(--r);
  background:rgba(255,255,255,.62);
  box-shadow:0 1px 0 rgba(26,26,26,.04);
  backdrop-filter:blur(10px);
  -webkit-backdrop-filter:blur(10px);
  margin:0 0 clamp(24px,3.4vw,38px);
}

.lede h2{font-size:20px;margin:0 0 8px}
.lede p{margin:0;font-size:16px;color:var(--muted)}

.paper-article section[id]{
  scroll-margin-top:106px;
  padding-top:clamp(22px,3vw,34px);
  border-top:1px solid var(--line);
}

.paper-article section[id] + section[id]{margin-top:clamp(22px,3vw,34px)}

.paper-article h2{
  font-size:clamp(22px,2.4vw,28px);
  margin:0 0 12px;
}

.paper-article h3{
  font-size:clamp(18px,1.9vw,21px);
  margin:22px 0 10px;
}

.paper-article h2 > span,
.paper-article h3 > span,
.side h2 > span,
.lede h2 > span,
.tail h2 > span{
  display:inline-block;
  padding-bottom:4px;
  border-bottom:2px solid var(--ink);
}

.paper-article p,
.paper-article li{
  font-family:'Rubik','Nunito Sans','PingFang SC',sans-serif;
  font-size:17px;
}

.paper-article blockquote{
  margin:18px 0;
  padding:12px 18px;
  border-left:3px solid var(--ink);
  background:var(--paper-2);
  border-radius:0 12px 12px 0;
}

.paper-article table{
  width:100%;
  border-collapse:collapse;
  margin:0 0 18px;
  font-size:16px;
}

.paper-article th,
.paper-article td{
  padding:9px 12px;
  border:1px solid var(--line);
  text-align:left;
}

.paper-article th{background:var(--paper-2);font-weight:600}

.paper-article a{text-underline-offset:3px}

.tail{
  margin-top:clamp(28px,4vw,44px);
  padding-top:clamp(22px,3vw,32px);
  border-top:1px solid var(--ink);
}

.tail h2{font-size:20px;margin:0 0 10px}

.tail-actions{
  display:flex;
  flex-wrap:wrap;
  gap:10px;
  margin:14px 0 0;
}

/* ---------- 页脚 ---------- */
.site-foot{
  padding:clamp(26px,4vw,46px) var(--pad) 18px;
  border-top:1px solid var(--ink);
  background:var(--paper-2);
  font-size:16px;
}

.foot-grid{
  display:grid;
  grid-template-columns:1.5fr 1fr 1fr 1fr;
  gap:clamp(16px,3vw,34px);
  max-width:var(--wrap);
  margin:0 auto;
}

.foot-logo{
  margin:0 0 8px;
  font-weight:600;
}

.foot-logo a{
  display:inline-flex;
  align-items:center;
  gap:9px;
  min-height:44px;
  text-decoration:none;
}

.foot-desc{
  margin:0 0 8px;
  font-size:16px;
  color:var(--muted);
}

.foot-meta{
  margin:0;
  font-size:15px;
  color:var(--muted);
  letter-spacing:.03em;
}

.site-foot dl{margin:0}

.site-foot dt{
  margin-bottom:8px;
  font-weight:600;
  letter-spacing:.05em;
}

.site-foot dd{
  margin:0;
  color:var(--muted);
}

.site-foot dd a{
  display:inline-flex;
  align-items:center;
  min-height:40px;
  padding:4px 0;
  text-decoration:none;
}

.site-foot dd a:hover{text-decoration:underline}

.foot-bottom{
  display:flex;
  flex-wrap:wrap;
  justify-content:space-between;
  gap:8px 20px;
  max-width:var(--wrap);
  margin:22px auto 0;
  padding-top:14px;
  border-top:1px solid var(--line);
  font-size:15px;
  color:var(--muted);
}

.foot-bottom p{margin:0}

.foot-links{
  display:flex;
  flex-wrap:wrap;
  gap:6px 18px;
}

.foot-links a{
  display:inline-flex;
  align-items:center;
  min-height:40px;
  text-decoration:none;
}

.foot-links a:hover{text-decoration:underline}

/* ---------- 断点 ---------- */
@media (max-width:1000px){
  .wrap{grid-template-columns:1fr}
  .side{position:static;order:2;margin-top:8px}
  .body-col{order:1}
  .foot-grid{grid-template-columns:1fr 1fr}
}

@media (max-width:880px){
  .hero{
    grid-template-columns:1fr;
    min-height:0;
    padding-top:clamp(20px,5vw,34px);
  }
  .hero-copy{order:1}
  .hero-plate{order:2;aspect-ratio:16/10;max-height:44vh}
  .hero h1{font-size:clamp(28px,7vw,38px)}
  .head-action{display:none}
}

@media (max-width:620px){
  body{font-size:16px}
  .quick-nav a{font-size:15px;padding:10px 9px}
  .brand-name{font-size:15px}
  .hero-facts{font-size:15px;gap:6px 14px}
  .lede{padding:16px 16px}
  .paper-article p,.paper-article li{font-size:16px}
  .foot-grid{grid-template-columns:1fr;gap:22px}
  .foot-bottom{flex-direction:column}
}

@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  .hero-img{transform:none}
}

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