:root{
  --ink:#1f1f1f;
  --paper:#ffffff;
  --mist:#f5f5f5;
  --line:#e5e5e5;
  --ink-2:#5c5c5c;
  --ink-3:#8e8e8e;
  --r:4px;
  --e1:0 1px 2px rgba(31,31,31,.05),0 2px 6px rgba(31,31,31,.05);
  --e2:0 2px 6px rgba(31,31,31,.06),0 10px 22px rgba(31,31,31,.06);
  --e3:0 6px 14px rgba(31,31,31,.07),0 20px 44px rgba(31,31,31,.08);
  --e4:0 10px 24px rgba(31,31,31,.09),0 34px 74px rgba(31,31,31,.12);
  --shell:1120px;
}

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

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

body{
  margin:0;
  overflow-x:hidden;
  background:var(--mist);
  color:var(--ink);
  font-family:'Inter',-apple-system,BlinkMacSystemFont,'Segoe UI','PingFang SC','Hiragino Sans GB','Microsoft YaHei',sans-serif;
  font-size:16px;
  line-height:1.7;
  font-weight:400;
  letter-spacing:.005em;
  -webkit-font-smoothing:antialiased;
}

img{max-width:100%;height:auto;display:block;}
p{margin:0 0 14px;}
menu{margin:0;padding:0;list-style:none;}
hr{border:0;height:1px;background:var(--line);}
a{color:var(--ink);}

section[id]{scroll-margin-top:96px;}
#main-content{scroll-margin-top:92px;}

.skip{
  position:absolute;left:14px;top:-70px;z-index:200;
  display:inline-flex;align-items:center;min-height:44px;padding:0 18px;
  background:var(--ink);color:#fff;text-decoration:none;border-radius:var(--r);
  box-shadow:var(--e3);
}
.skip:focus{top:14px;}

/* ---------- 顶部三层栏 ---------- */
.masthead{
  position:sticky;top:0;z-index:50;
  display:grid;grid-template-columns:auto minmax(0,1fr) auto;
  align-items:center;gap:12px;
  padding:10px 18px;
  background:rgba(255,255,255,.84);
  -webkit-backdrop-filter:blur(16px) saturate(130%);
  backdrop-filter:blur(16px) saturate(130%);
  border-bottom:1px solid var(--line);
  box-shadow:var(--e1);
}

.nav-shell{justify-self:start;}
.nav-toggle{
  position:relative;z-index:70;
  display:inline-flex;flex-direction:column;align-items:center;justify-content:center;gap:4px;
  min-height:46px;min-width:58px;padding:6px 10px;
  cursor:pointer;list-style:none;
  background:var(--paper);border-radius:var(--r);box-shadow:var(--e2);
}
.nav-toggle::-webkit-details-marker{display:none;}
.bar{display:block;width:22px;height:2px;background:var(--ink);transition:transform .3s ease,opacity .25s ease;}
.toggle-word{font-size:13px;letter-spacing:.16em;color:var(--ink-2);line-height:1.2;}
.nav-shell[open] .bar:nth-child(1){transform:translateY(6px) rotate(45deg);}
.nav-shell[open] .bar:nth-child(2){opacity:0;}
.nav-shell[open] .bar:nth-child(3){transform:translateY(-6px) rotate(-45deg);}
.nav-shell[open] .nav-toggle{box-shadow:var(--e4);}

.panel{
  position:fixed;inset-block:0;z-index:60;
  width:50%;
  display:none;flex-direction:column;justify-content:center;gap:2px;
  padding:110px 30px 48px;
  background:rgba(245,245,245,.9);
  -webkit-backdrop-filter:blur(22px) saturate(130%);
  backdrop-filter:blur(22px) saturate(130%);
  box-shadow:var(--e4);
}
.nav-shell[open] .panel{display:flex;}
.panel--l{left:0;align-items:flex-end;text-align:right;border-right:1px solid rgba(31,31,31,.07);}
.panel--r{right:0;align-items:flex-start;}

.panel a{
  display:inline-flex;align-items:center;min-height:46px;
  padding:6px 12px;border-radius:var(--r);
  text-decoration:none;color:var(--ink);
  font-size:clamp(18px,2.3vw,26px);font-weight:500;letter-spacing:.02em;
  transition:background .25s ease,transform .25s ease,box-shadow .25s ease;
}
.panel a:hover,.panel a:focus-visible{
  background:var(--paper);box-shadow:var(--e2);transform:translateY(-2px);
}

.brand{
  justify-self:center;min-width:0;
  display:inline-flex;align-items:center;gap:9px;min-height:46px;padding:0 8px;
  text-decoration:none;color:var(--ink);
  border-radius:var(--r);
}
.brand-mark{width:30px;height:30px;border-radius:var(--r);box-shadow:var(--e1);}
.brand-name{
  font-size:16px;font-weight:600;letter-spacing:.03em;
  white-space:nowrap;overflow:hidden;text-overflow:ellipsis;max-width:100%;
}

.cta{
  justify-self:end;
  display:inline-flex;align-items:center;min-height:44px;padding:0 16px;
  background:var(--ink);color:#fff;text-decoration:none;
  border-radius:var(--r);font-size:16px;font-weight:500;
  box-shadow:var(--e2);transition:transform .25s ease,box-shadow .25s ease;
}
.cta:hover,.cta:focus-visible{transform:translateY(-2px);box-shadow:var(--e3);}

/* ---------- 自动轮播细条 ---------- */
.ticker{
  overflow:hidden;background:var(--paper);
  border-bottom:1px solid var(--line);
  box-shadow:var(--e1);
}
.ticker-track{
  display:flex;gap:30px;width:max-content;
  padding:6px 0 6px 20px;
  animation:slide 26s linear infinite;
}
.ticker-track span{
  font-size:14px;letter-spacing:.14em;color:var(--ink-3);
  display:inline-flex;align-items:center;
}
.ticker-track span::after{content:'·';margin-left:30px;color:var(--line);}
@keyframes slide{to{transform:translateX(-50%);}}

/* ---------- 首屏 ---------- */
.hero{
  position:relative;overflow:hidden;
  max-width:var(--shell);margin:0 auto;
  min-height:70vh;
  padding:44px 20px 58px;
  display:flex;flex-direction:column;gap:24px;
}
.ghost{
  position:absolute;right:2px;top:64px;z-index:0;
  font-size:clamp(120px,26vw,290px);line-height:.78;font-weight:700;
  letter-spacing:-.05em;color:rgba(31,31,31,.055);
  pointer-events:none;
}
.hero-copy{
  position:relative;z-index:2;
  align-self:flex-end;text-align:right;max-width:760px;
  display:flex;flex-direction:column;align-items:flex-end;gap:14px;
}
.kicker{
  margin:0;font-size:13px;letter-spacing:.2em;color:var(--ink-3);
  background:var(--paper);padding:5px 12px;border-radius:var(--r);
  box-shadow:var(--e1);
}
.hero h1{
  margin:0;
  font-size:clamp(30px,5vw,54px);
  line-height:1.14;font-weight:600;letter-spacing:-.02em;
}
.sub{
  margin:0;max-width:560px;
  font-size:17px;line-height:1.75;color:var(--ink-2);
}
.hero-media{
  position:relative;z-index:1;margin-top:auto;
  border-radius:var(--r);overflow:hidden;
  min-height:96px;
  background:linear-gradient(155deg,#ffffff 0%,#ededed 62%,#e2e2e2 100%);
  box-shadow:var(--e4);
}
.hero-media img{width:100%;}

/* ---------- 正文两层 ---------- */
main{
  max-width:var(--shell);margin:0 auto;
  padding:0 20px 64px;
  display:grid;grid-template-columns:minmax(0,1fr) 268px;
  gap:26px;align-items:start;
}
.sheet{
  position:relative;z-index:3;
  margin-top:-40px;
  background:var(--paper);
  border-radius:var(--r);
  box-shadow:var(--e3);
  padding:clamp(18px,3vw,40px);
}
.sheet-inner{counter-reset:sec;}
.sheet-inner > section{
  padding:26px 0;
  border-top:1px solid var(--line);
}
.sheet-inner > section:first-child{border-top:0;padding-top:0;}
.sheet-inner > section::before{
  counter-increment:sec;
  content:"0" counter(sec);
  display:block;margin-bottom:8px;
  font-size:13px;letter-spacing:.26em;color:var(--ink-3);font-weight:500;
}
.sheet-inner h2{
  margin:0 0 12px;font-size:clamp(21px,2.6vw,28px);line-height:1.32;
  font-weight:600;letter-spacing:-.012em;
}
.sheet-inner h3{margin:20px 0 10px;font-size:19px;line-height:1.4;font-weight:600;}
.sheet-inner hr{margin:12px 0 18px;}
.sheet-inner p{color:var(--ink-2);}
.sheet-inner strong{color:var(--ink);font-weight:600;}
.sheet-inner a{text-decoration-thickness:1px;text-underline-offset:3px;}
.sheet-inner ul,.sheet-inner ol{padding-left:22px;color:var(--ink-2);}
.sheet-inner li{margin:6px 0;}
.sheet-inner blockquote{
  margin:18px 0;padding:14px 18px;
  background:var(--mist);border-left:2px solid var(--ink);border-radius:var(--r);
  box-shadow:var(--e1);
}
.sheet-inner table{width:100%;border-collapse:collapse;font-size:16px;}
.sheet-inner th,.sheet-inner td{border-bottom:1px solid var(--line);padding:9px 10px;text-align:left;}
.sheet-inner th{background:var(--mist);font-weight:600;}

/* ---------- 右侧栏 ---------- */
.rail{
  position:sticky;top:86px;
  display:grid;gap:16px;align-content:start;
  padding-top:0;
}
.rail-card{
  background:var(--paper);border-radius:var(--r);
  padding:16px 16px 12px;
  box-shadow:var(--e2);
}
.rail-card h2{margin:0 0 9px;font-size:17px;line-height:1.4;font-weight:600;}
.rail-card h3{margin:0 0 9px;font-size:17px;line-height:1.4;font-weight:600;}
.rail-card hr{margin:0 0 10px;}
.rail-card p{font-size:15px;line-height:1.72;color:var(--ink-2);margin:0 0 10px;}
.rail-list{display:grid;gap:2px;}
.rail-list a{
  display:flex;align-items:center;min-height:40px;padding:4px 9px;
  border-radius:var(--r);text-decoration:none;font-size:16px;color:var(--ink);
  transition:background .2s ease,transform .2s ease;
}
.rail-list a:hover,.rail-list a:focus-visible{background:var(--mist);transform:translateX(-2px);}
.rail-card--soft{background:linear-gradient(180deg,#ffffff,#fafafa);box-shadow:var(--e1);}

/* ---------- 结尾大按钮块 ---------- */
.outro{
  max-width:var(--shell);margin:0 auto;padding:0 20px 56px;
}
.outro{
  position:relative;
}
.outro > *{max-width:var(--shell);}
.outro{
  display:grid;gap:12px;justify-items:start;
}
.outro-kicker{margin:0;font-size:13px;letter-spacing:.2em;color:var(--ink-3);}
.outro-line{
  margin:0;max-width:640px;font-size:17px;line-height:1.7;color:var(--ink-2);
}
.outro-cta{
  display:inline-flex;align-items:center;min-height:52px;padding:0 26px;
  margin-top:6px;
  background:var(--ink);color:#fff;text-decoration:none;
  border-radius:var(--r);font-size:16px;font-weight:500;letter-spacing:.02em;
  box-shadow:var(--e3);
  transition:transform .25s ease,box-shadow .25s ease;
}
.outro-cta:hover,.outro-cta:focus-visible{transform:translateY(-3px);box-shadow:var(--e4);}

/* ---------- 极简页脚 ---------- */
.colophon{
  padding:38px 20px 54px;
  display:grid;gap:8px;justify-items:center;text-align:center;
  border-top:1px solid var(--line);
  background:var(--paper);
  box-shadow:0 -2px 12px rgba(31,31,31,.04);
}
.colophon p{margin:0;font-size:16px;color:var(--ink);}
.colophon small{font-size:15px;line-height:1.7;color:var(--ink-3);max-width:620px;}

/* ---------- 滚动浮现 ---------- */
.reveal{
  opacity:0;transform:translateY(20px);
  transition:opacity .7s ease,transform .7s cubic-bezier(.2,.72,.2,1);
}
.reveal.is-in{opacity:1;transform:none;}

:focus-visible{outline:2px solid var(--ink);outline-offset:3px;}

@media (max-width:900px){
  main{grid-template-columns:minmax(0,1fr);gap:20px;}
  .rail{position:static;padding-top:0;}
  .rail-card{padding:14px 14px 10px;}
}

@media (max-width:640px){
  .masthead{padding:8px 12px;gap:8px;}
  .brand-mark{display:none;}
  .brand{padding:0 4px;}
  .hero{padding:30px 16px 48px;min-height:62vh;}
  .ghost{top:40px;font-size:clamp(96px,34vw,180px);}
  .hero h1{font-size:clamp(27px,7.4vw,36px);}
  .sub{font-size:16px;}
  main{padding:0 16px 48px;}
  .sheet{margin-top:-30px;}
  .outro{padding:0 16px 44px;}
  .panel{padding:96px 14px 40px;width:50%;}
  .panel a{font-size:17px;padding:6px 8px;}
  .colophon{padding:30px 16px 44px;}
}

@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto;}
  .reveal{opacity:1;transform:none;transition:none;}
  .ticker-track{animation:none;}
  .cta:hover,.outro-cta:hover,.panel a:hover,.rail-list a:hover{transform:none;}
}

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