@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{
  --ink:#000000;
  --paper:#ffffff;
  --line:rgba(0,0,0,.16);
  --mute:rgba(0,0,0,.56);
  --display:'Outfit','Work Sans',system-ui,-apple-system,'PingFang SC','Microsoft YaHei',sans-serif;
  --text:'Work Sans',system-ui,-apple-system,'PingFang SC','Microsoft YaHei',sans-serif;
  --pad:clamp(18px,4.5vw,64px);
}

*,*::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:var(--text);
  font-size:17px;
  line-height:1.68;
  font-weight:400;
  letter-spacing:.01em;
  overflow-x:hidden;
  -webkit-font-smoothing:antialiased;
}

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

a{color:var(--ink);text-underline-offset:.22em;text-decoration-thickness:1px}

h1,h2,h3,h4{
  font-family:var(--display);
  font-weight:700;
  line-height:1.06;
  letter-spacing:-.024em;
  margin:0 0 .7rem;
}

h2{font-size:clamp(1.6rem,3.4vw,2.5rem)}
h3{font-size:clamp(1.2rem,2.2vw,1.6rem);letter-spacing:-.015em}

p{margin:0 0 1.05em;max-width:64ch}

hr{
  border:0;
  height:2px;
  width:64px;
  background:var(--ink);
  margin:.2rem 0 1.5rem;
}

[id]{scroll-margin-top:clamp(16px,4vw,40px)}

/* ---------- 顶部细条 ---------- */
.strip{
  display:flex;
  align-items:center;
  justify-content:center;
  gap:.55rem;
  padding:.55rem var(--pad);
  font-size:.9rem;
  letter-spacing:.3em;
  border-bottom:1px solid var(--line);
  background:var(--paper);
  color:var(--mute);
}
.strip .dot{letter-spacing:0;opacity:.5}

/* ---------- 品牌行 ---------- */
.brandline{
  padding:clamp(14px,2.6vw,28px) var(--pad) clamp(6px,1.2vw,14px);
}

.brand{
  display:inline-flex;
  align-items:center;
  gap:.7rem;
  text-decoration:none;
  min-height:44px;
}

.brand-mark{
  width:30px;
  height:30px;
  object-fit:contain;
  filter:grayscale(1) contrast(1.2);
}

.brand-name{
  font-family:var(--display);
  font-weight:700;
  font-size:clamp(1.6rem,4.4vw,2.6rem);
  letter-spacing:-.035em;
  line-height:1;
}

/* ---------- 主导航 nav > ol > li > a ---------- */
.nav-main{
  padding:0 var(--pad) .7rem;
  border-bottom:2px solid var(--ink);
}

.nav-main ol{
  list-style:none;
  display:flex;
  flex-wrap:wrap;
  gap:0 clamp(14px,2.4vw,30px);
  margin:0;
  padding:0;
  counter-reset:nv;
}

.nav-main li{
  counter-increment:nv;
  display:flex;
}

.nav-main a{
  display:inline-flex;
  align-items:center;
  gap:.4rem;
  min-height:44px;
  padding:.4rem 0;
  text-decoration:none;
  font-size:1rem;
  letter-spacing:.02em;
  border-bottom:2px solid transparent;
  transition:border-color .25s ease,color .25s ease;
}

.nav-main a::before{
  content:counter(nv,decimal-leading-zero);
  font-family:var(--display);
  font-size:.72rem;
  font-weight:500;
  letter-spacing:0;
  color:var(--mute);
  transform:translateY(-.42em);
}

.nav-main a:hover,
.nav-main a:focus-visible{
  border-bottom-color:var(--ink);
}

/* ---------- 首屏 ---------- */
.hero{
  position:relative;
  isolation:isolate;
  display:flex;
  align-items:flex-end;
  justify-content:flex-end;
  min-height:45vh;
  padding:clamp(30px,6vw,64px) var(--pad);
  background:var(--ink);
  color:var(--paper);
  overflow:hidden;
}

.hero-media{
  position:absolute;
  inset:0;
  z-index:-2;
  overflow:hidden;
}

.hero-media img{
  width:100%;
  height:100%;
  object-fit:cover;
  filter:grayscale(1) contrast(1.12);
  opacity:.6;
  transform:scale(1.06);
  will-change:transform;
}

.hero::after{
  content:"";
  position:absolute;
  inset:0;
  z-index:-1;
  background:linear-gradient(102deg,#000 6%,rgba(0,0,0,.42) 58%,rgba(0,0,0,.86) 100%);
}

.hero-copy{
  text-align:right;
  max-width:min(100%,44rem);
}

.badge{
  display:inline-block;
  margin:0 0 1rem;
  padding:.32rem .8rem;
  border:1px solid var(--paper);
  font-size:.9rem;
  letter-spacing:.26em;
  max-width:none;
}

.hero h1{
  margin:0;
  font-size:clamp(2.1rem,7.4vw,5.2rem);
  line-height:1;
  letter-spacing:-.04em;
}

.dek{
  margin:1rem 0 0 auto;
  max-width:36rem;
  font-size:1rem;
  line-height:1.6;
  color:rgba(255,255,255,.76);
}

/* ---------- 主体：div + 右侧 aside ---------- */
.spread{
  display:grid;
  grid-template-columns:minmax(0,1fr);
  padding:clamp(30px,6vw,68px) var(--pad) clamp(44px,8vw,96px);
  border-bottom:1px solid var(--line);
}

.prose{
  min-width:0;
  font-size:1.05rem;
}

.prose > article{
  padding:clamp(22px,3.6vw,40px) 0;
  border-top:1px solid var(--line);
}

.prose > article:first-child{
  border-top:0;
  padding-top:0;
}

.prose > article > *{
  max-width:66ch;
}

.prose > article:first-child > p:first-of-type::first-letter{
  float:left;
  font-family:var(--display);
  font-weight:700;
  font-size:3.3em;
  line-height:.86;
  padding:.06em .14em 0 0;
  letter-spacing:-.04em;
}

.prose h2{margin-bottom:.5rem}
.prose h3{margin-bottom:.4rem}

.prose ul,
.prose ol{
  padding-left:1.35em;
  margin:0 0 1.1em;
  max-width:64ch;
}

.prose li{margin:0 0 .45em}

.prose blockquote{
  margin:1.6rem 0;
  padding:.2rem 0 .2rem 1.3rem;
  border-left:5px solid var(--ink);
  font-family:var(--display);
  font-size:clamp(1.15rem,2.4vw,1.5rem);
  line-height:1.35;
  letter-spacing:-.02em;
  max-width:56ch;
}

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

.prose figure{margin:1.6rem 0}
.prose figcaption{
  margin-top:.5rem;
  font-size:.9rem;
  letter-spacing:.06em;
  color:var(--mute);
}

.prose table{
  width:100%;
  border-collapse:collapse;
  margin:0 0 1.4em;
  font-size:1rem;
}

.prose th,.prose td{
  border-bottom:1px solid var(--line);
  padding:.6rem .5rem;
  text-align:left;
}

.prose th{border-bottom:2px solid var(--ink);font-family:var(--display)}

.prose code{
  font-size:.94em;
  background:rgba(0,0,0,.06);
  padding:.1em .35em;
}

/* ---------- aside（内容右侧） ---------- */
.rail{
  align-self:start;
  margin-top:clamp(32px,5vw,0);
  padding-top:1rem;
  border-top:2px solid var(--ink);
}

.rail h2{
  font-size:1rem;
  letter-spacing:.3em;
  font-weight:600;
  margin:0 0 .5rem;
}

.rail hr{width:36px;height:2px;margin:0 0 1rem}

.rail ol{
  list-style:none;
  margin:0;
  padding:0;
  counter-reset:rl;
}

.rail li{
  counter-increment:rl;
  border-bottom:1px solid var(--line);
}

.rail a{
  display:flex;
  align-items:center;
  gap:.6rem;
  min-height:44px;
  padding:.4rem 0;
  text-decoration:none;
  font-size:.98rem;
}

.rail a::before{
  content:counter(rl,decimal-leading-zero);
  font-family:var(--display);
  font-size:.76rem;
  color:var(--mute);
}

.rail a:hover{text-decoration:underline}

/* ---------- 页脚单行 ---------- */
.site-footer{
  display:flex;
  flex-wrap:wrap;
  align-items:center;
  gap:.4rem clamp(14px,3vw,32px);
  padding:1.4rem var(--pad);
  border-top:2px solid var(--ink);
  font-size:.94rem;
}

.foot-brand a{
  display:inline-flex;
  align-items:center;
  min-height:44px;
  font-family:var(--display);
  font-weight:700;
  letter-spacing:-.02em;
  text-decoration:none;
}

.foot-nav ol{
  list-style:none;
  display:flex;
  flex-wrap:wrap;
  gap:0 1rem;
  margin:0;
  padding:0;
}

.foot-nav a{
  display:inline-flex;
  align-items:center;
  min-height:44px;
  padding:.2rem 0;
  text-decoration:none;
  color:var(--mute);
}

.foot-nav a:hover{color:var(--ink);text-decoration:underline}

.copy{
  margin:0 0 0 auto;
  max-width:none;
  letter-spacing:.12em;
  color:var(--mute);
}

/* ---------- 动效 ---------- */
.js [data-reveal]{
  opacity:0;
  transform:translate3d(0,16px,0);
  transition:opacity .7s ease,transform .8s cubic-bezier(.19,.7,.22,1);
}

.js [data-reveal].in{
  opacity:1;
  transform:none;
}

/* ---------- 断点 ---------- */
@media (min-width:1000px){
  .spread{
    grid-template-columns:minmax(0,1fr) minmax(210px,264px);
    column-gap:clamp(28px,5vw,76px);
  }
  .rail{
    position:sticky;
    top:1.5rem;
    margin-top:0;
  }
  .prose > article > *{
    max-width:62ch;
  }
}

@media (max-width:999px){
  .hero{min-height:44vh}
  .copy{margin-left:0}
}

@media (max-width:600px){
  .strip{letter-spacing:.2em;font-size:.88rem}
  .nav-main ol{gap:0 .9rem}
  .nav-main a{font-size:.98rem}
  .hero{padding-top:clamp(26px,9vw,48px)}
  .hero-copy{max-width:100%}
  .dek{font-size:.98rem}
  .site-footer{gap:.2rem 1rem}
}

@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  .js [data-reveal]{opacity:1;transform:none;transition:none}
  .hero-media img{transform:none}
}

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