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

:root{
  --ink:#1f1f1f;
  --ink-soft:#3a3a3a;
  --ink-mute:#6d6d6d;
  --paper:#ffffff;
  --paper-2:#f5f5f5;
  --line:rgba(31,31,31,.10);
  --r:28px;
  --e1:0 1px 2px rgba(31,31,31,.05),0 2px 6px rgba(31,31,31,.05);
  --e2:0 4px 12px rgba(31,31,31,.06),0 12px 26px rgba(31,31,31,.06);
  --e3:0 10px 24px rgba(31,31,31,.08),0 24px 48px rgba(31,31,31,.07);
  --e4:0 18px 44px rgba(31,31,31,.10),0 40px 84px rgba(31,31,31,.08);
  --max:1180px;
  --rail:56px;
}

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

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

body{
  margin:0;
  overflow-x:clip;
  background:var(--paper-2);
  color:var(--ink);
  font-family:"Be Vietnam Pro","Noto Sans","PingFang SC","Hiragino Sans GB","Microsoft YaHei",system-ui,sans-serif;
  font-size:16px;
  line-height:1.75;
  -webkit-font-smoothing:antialiased;
  text-rendering:optimizeLegibility;
}

img{max-width:100%;height:auto;display:block}
a{color:inherit;text-decoration:none}
button{font:inherit}

a:focus-visible,
button:focus-visible,
input:focus-visible{
  outline:2px solid var(--ink);
  outline-offset:3px;
  border-radius:8px;
}

.wrap{
  width:100%;
  max-width:var(--max);
  margin-inline:auto;
  padding-inline:clamp(16px,4vw,44px);
}

/* ---------- 顶栏 ---------- */
.topbar{
  position:relative;
  z-index:40;
  background:rgba(255,255,255,.88);
  backdrop-filter:blur(14px) saturate(1.15);
  border-bottom:1px solid var(--line);
}

.bar{
  display:grid;
  grid-template-columns:1fr auto 1fr;
  align-items:center;
  gap:clamp(6px,1.8vw,22px);
  min-height:78px;
  padding-block:8px;
}

.side{
  display:flex;
  align-items:center;
  gap:clamp(4px,1.2vw,16px);
}

.side.left{justify-self:start}
.side.right{justify-self:end;gap:10px}
.side.right-in{gap:clamp(4px,1.2vw,14px)}

.side a{
  display:inline-flex;
  align-items:center;
  min-height:44px;
  padding:0 6px;
  font-size:.95rem;
  font-weight:500;
  color:var(--ink-soft);
  white-space:nowrap;
  border-bottom:2px solid transparent;
  transition:color .2s ease,border-color .2s ease;
}

.side a:hover{color:var(--ink);border-bottom-color:var(--ink)}

.brand{
  display:inline-flex;
  align-items:center;
  min-height:44px;
  padding:0 20px;
  border-radius:999px;
  background:var(--paper);
  box-shadow:var(--e2);
  font-size:1.05rem;
  font-weight:700;
  letter-spacing:.04em;
  white-space:nowrap;
  transition:transform .22s ease,box-shadow .22s ease;
}

.brand:hover{transform:translateY(-2px);box-shadow:var(--e3)}

.cta{
  display:inline-flex;
  align-items:center;
  min-height:46px;
  padding:0 22px;
  border-radius:999px;
  background:var(--ink);
  color:#fff;
  font-size:.95rem;
  font-weight:600;
  white-space:nowrap;
  box-shadow:var(--e3);
  transition:transform .22s ease,box-shadow .22s ease,color .2s ease;
}

.cta:hover{
  color:#fff;
  border-bottom-color:transparent;
  transform:translateY(-2px);
  box-shadow:var(--e4);
}

/* ---------- 粘性锚点条 ---------- */
.rail{
  position:sticky;
  top:0;
  z-index:50;
  background:rgba(255,255,255,.76);
  backdrop-filter:blur(16px) saturate(1.2);
  border-bottom:1px solid var(--line);
  box-shadow:var(--e1);
}

.rail-inner{
  display:flex;
  gap:8px;
  overflow-x:auto;
  padding-block:8px;
  scrollbar-width:none;
}

.rail-inner::-webkit-scrollbar{display:none}

.rail-inner a{
  flex:0 0 auto;
  display:inline-flex;
  align-items:center;
  min-height:40px;
  padding:0 15px;
  border-radius:999px;
  background:var(--paper);
  box-shadow:var(--e1);
  font-size:.875rem;
  font-weight:500;
  color:var(--ink-soft);
  white-space:nowrap;
  transition:background .2s ease,color .2s ease,box-shadow .2s ease;
}

.rail-inner a:hover,
.rail-inner a.on{
  background:var(--ink);
  color:#fff;
  box-shadow:var(--e2);
}

/* ---------- 首屏 ---------- */
.hero{
  position:relative;
  isolation:isolate;
  overflow:hidden;
  display:flex;
  align-items:center;
  justify-content:center;
  min-height:min(46vh,430px);
  padding:clamp(30px,6vw,66px) 0 clamp(46px,9vw,92px);
  background:linear-gradient(178deg,#ffffff 0%,#f7f7f7 62%,#f5f5f5 100%);
  border-bottom-left-radius:clamp(38px,8vw,90px);
  border-bottom-right-radius:clamp(38px,8vw,90px);
  border-top:1px solid rgba(31,31,31,.04);
}

.hero-in{position:relative;z-index:2}

.hero h1{
  margin:0 auto;
  max-width:22ch;
  text-align:center;
  font-size:clamp(1.7rem,5vw,3.1rem);
  line-height:1.28;
  font-weight:700;
  letter-spacing:-.02em;
  text-shadow:0 1px 0 #fff,0 10px 24px rgba(255,255,255,.9);
}

.hero-art{
  position:absolute;
  inset:0;
  margin:0;
  z-index:-1;
  overflow:hidden;
  pointer-events:none;
}

.ghost{
  position:absolute;
  left:50%;
  top:50%;
  transform:translate(-50%,-50%);
  font-size:clamp(58px,16vw,186px);
  font-weight:700;
  letter-spacing:-.04em;
  line-height:1;
  color:rgba(31,31,31,.055);
  white-space:nowrap;
  will-change:transform;
}

.hero-img{
  position:absolute;
  right:clamp(8px,4vw,58px);
  bottom:clamp(14px,3vw,28px);
  width:clamp(92px,20vw,220px);
  filter:drop-shadow(0 18px 30px rgba(31,31,31,.16));
  opacity:.96;
}

/* ---------- 主体排布 ---------- */
.body{
  display:grid;
  grid-template-columns:minmax(0,1fr) 268px;
  align-items:start;
  gap:clamp(16px,3vw,40px);
  padding-block:clamp(26px,4vw,48px) clamp(44px,7vw,80px);
}

.prose{
  display:flex;
  flex-direction:column;
  gap:clamp(14px,2vw,22px);
  min-width:0;
}

.prose > article{
  position:relative;
  z-index:1;
  background:var(--paper);
  border-radius:var(--r);
  padding:clamp(22px,3.4vw,42px);
  box-shadow:var(--e2);
  scroll-margin-top:calc(var(--rail) + 18px);
  animation:rise .6s cubic-bezier(.22,.72,.24,1) both;
}

.prose > article:nth-child(odd){margin-right:clamp(0px,2vw,26px)}
.prose > article:nth-child(even){margin-left:clamp(0px,2vw,26px);box-shadow:var(--e3)}
.prose > article:nth-child(3n){z-index:2}
.prose > article:nth-child(1){animation-delay:.02s}
.prose > article:nth-child(2){animation-delay:.06s}
.prose > article:nth-child(3){animation-delay:.1s}
.prose > article:nth-child(4){animation-delay:.14s}
.prose > article:nth-child(5){animation-delay:.18s}
.prose > article:nth-child(6){animation-delay:.22s}
.prose > article:nth-child(7){animation-delay:.26s}

@keyframes rise{
  from{opacity:0;transform:translate3d(0,22px,0)}
  to{opacity:1;transform:translate3d(0,0,0)}
}

.prose h2{
  margin:0 0 .6em;
  font-size:clamp(1.42rem,3.1vw,1.92rem);
  line-height:1.34;
  letter-spacing:-.015em;
  font-weight:700;
}

.prose h3{
  margin:1.4em 0 .5em;
  font-size:clamp(1.12rem,2.2vw,1.28rem);
  line-height:1.45;
  letter-spacing:-.01em;
}

.prose h2 + h3{margin-top:.2em}

.prose p{
  margin:0 0 1em;
  color:var(--ink-soft);
  font-size:1.0625rem;
  line-height:1.85;
}

.prose p:last-child,
.prose ul:last-child,
.prose ol:last-child,
.prose blockquote:last-child{margin-bottom:0}

.prose ul,
.prose ol{
  margin:0 0 1em;
  padding-left:1.3em;
  color:var(--ink-soft);
}

.prose li{margin-block:.4em}
.prose li::marker{color:var(--ink-mute)}
.prose strong{color:var(--ink);font-weight:600}
.prose a{box-shadow:inset 0 -1px 0 var(--ink)}
.prose a:hover{background:var(--paper-2)}

.prose small{
  display:inline-block;
  font-size:.8rem;
  letter-spacing:.14em;
  color:var(--ink-mute);
}

.prose blockquote{
  margin:0 0 1em;
  padding:14px 18px;
  border-radius:18px;
  background:var(--paper-2);
  box-shadow:inset 0 0 0 1px var(--line);
  color:var(--ink-soft);
}

.prose blockquote p:last-child{margin-bottom:0}

.prose table{
  display:block;
  overflow-x:auto;
  width:100%;
  margin:0 0 1em;
  border-collapse:collapse;
  font-size:.95rem;
}

.prose th,
.prose td{
  padding:10px 13px;
  text-align:left;
  white-space:nowrap;
  box-shadow:inset 0 -1px 0 var(--line);
}

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

.prose time{
  font-variant-numeric:tabular-nums;
  font-size:.9rem;
  color:var(--ink-mute);
}

.prose img{
  border-radius:20px;
  box-shadow:var(--e2);
  margin:0 0 1em;
}

.prose figure{margin:0 0 1em}

/* ---------- 侧栏 ---------- */
.aside{
  position:sticky;
  top:calc(var(--rail) + 18px);
  background:var(--paper);
  border-radius:var(--r);
  padding:22px 20px;
  box-shadow:var(--e3);
}

.eyebrow{
  display:block;
  font-size:.76rem;
  letter-spacing:.18em;
  color:var(--ink-mute);
  line-height:1.4;
}

.aside-title{
  margin:.18em 0 .85em;
  font-size:1.15rem;
  letter-spacing:-.01em;
  font-weight:700;
}

.aside-list{
  list-style:none;
  margin:0;
  padding:0;
  display:flex;
  flex-direction:column;
  gap:7px;
}

.aside-list a{
  display:flex;
  align-items:center;
  min-height:42px;
  padding:6px 12px;
  border-radius:14px;
  background:var(--paper-2);
  box-shadow:var(--e1);
  font-size:.95rem;
  color:var(--ink-soft);
  transition:transform .18s ease,box-shadow .18s ease,color .18s ease;
}

.aside-list a:hover{
  transform:translateX(-3px);
  box-shadow:var(--e2);
  color:var(--ink);
}

/* ---------- 页脚 ---------- */
.foot{
  position:relative;
  z-index:3;
  margin-top:clamp(18px,4vw,36px);
  background:var(--ink);
  color:#f5f5f5;
  border-top-left-radius:clamp(30px,6vw,64px);
  border-top-right-radius:clamp(30px,6vw,64px);
  box-shadow:0 -22px 60px rgba(31,31,31,.20);
}

.foot-top{
  display:grid;
  grid-template-columns:1.15fr .85fr;
  gap:clamp(22px,5vw,60px);
  padding-block:clamp(34px,6vw,62px) clamp(24px,4vw,40px);
}

.foot address{
  font-style:normal;
  font-size:1.3rem;
  font-weight:700;
  letter-spacing:.03em;
  margin-bottom:16px;
}

.sub{
  display:flex;
  flex-wrap:wrap;
  gap:10px;
  max-width:400px;
}

.sub-input{
  flex:1 1 170px;
  min-height:46px;
  padding:0 17px;
  border-radius:999px;
  border:1px solid rgba(255,255,255,.2);
  background:rgba(255,255,255,.08);
  color:#fff;
  font-size:.95rem;
}

.sub-input::placeholder{color:rgba(255,255,255,.55)}

.sub-btn{
  min-height:46px;
  padding:0 24px;
  border:0;
  border-radius:999px;
  background:#fff;
  color:var(--ink);
  font-size:.95rem;
  font-weight:600;
  cursor:pointer;
  box-shadow:var(--e3);
  transition:transform .18s ease;
}

.sub-btn:hover{transform:translateY(-2px)}

.foot-links{
  list-style:none;
  display:flex;
  flex-wrap:wrap;
  gap:8px;
  margin:22px 0 0;
  padding:0;
}

.foot-links a{
  display:inline-flex;
  align-items:center;
  min-height:42px;
  padding:0 15px;
  border-radius:999px;
  background:rgba(255,255,255,.08);
  font-size:.9rem;
  transition:background .18s ease;
}

.foot-links a:hover{background:rgba(255,255,255,.2)}

.foot-nav dl{
  display:grid;
  grid-template-columns:auto 1fr;
  gap:6px 14px;
  margin:0;
  align-items:start;
}

.foot-nav dt{
  font-size:.78rem;
  letter-spacing:.16em;
  color:rgba(255,255,255,.5);
  padding-top:14px;
}

.foot-nav dd{
  margin:0;
  display:flex;
  flex-wrap:wrap;
  gap:4px 14px;
}

.foot-nav dd a{
  display:inline-flex;
  align-items:center;
  min-height:42px;
  font-size:.98rem;
  box-shadow:inset 0 -1px 0 rgba(255,255,255,.28);
  transition:box-shadow .18s ease;
}

.foot-nav dd a:hover{box-shadow:inset 0 -2px 0 #fff}

.foot-bottom{
  border-top:1px solid rgba(255,255,255,.14);
  padding-block:18px 26px;
  text-align:center;
  font-size:.85rem;
  color:rgba(255,255,255,.6);
}

.copy{margin:0}

/* ---------- 窄屏 ---------- */
@media (max-width:900px){
  .bar{
    grid-template-columns:1fr;
    min-height:0;
    gap:4px;
    padding-block:10px 6px;
  }

  .brand{
    order:-1;
    justify-self:center;
    font-size:1rem;
  }

  .side,
  .side.left,
  .side.right{
    justify-self:center;
    justify-content:center;
    flex-wrap:wrap;
    gap:5px;
  }

  .side a{
    padding:0 12px;
    border-radius:999px;
    background:var(--paper);
    box-shadow:var(--e1);
    font-size:.9rem;
    border-bottom-width:0;
  }

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

  .cta{margin-top:6px}

  .body{
    grid-template-columns:1fr;
    gap:22px;
  }

  .prose > article:nth-child(odd),
  .prose > article:nth-child(even){margin-inline:0}

  .aside{position:static}

  .foot-top{grid-template-columns:1fr}

  .hero{min-height:44vh}
}

@media (max-width:520px){
  .hero h1{font-size:1.65rem}
  .ghost{font-size:clamp(52px,20vw,110px)}
  .prose p{font-size:1.05rem}
  .foot-nav dl{grid-template-columns:1fr}
  .foot-nav dt{padding-top:8px}
}

@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  .prose > article{animation:none}
  .brand:hover,
  .cta:hover,
  .sub-btn:hover,
  .aside-list a:hover{transform:none}
}

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