@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700&family=JetBrains+Mono:wght@400;500&family=Space+Grotesk:wght@500;600;700&display=swap');

:root{
  --bg:#f5f5f5;
  --surface:#ffffff;
  --ink:#1f1f1f;
  --muted:#5d5d5d;
  --line:rgba(31,31,31,.1);
  --glass:rgba(255,255,255,.72);
  --r:28px;
  --shadow:0 4px 6px rgba(0,0,0,.05);
  --shadow-lift:0 10px 30px rgba(0,0,0,.08);
}

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

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

body{
  margin:0;
  background:var(--bg);
  color:var(--ink);
  font-family:'Inter',system-ui,-apple-system,'PingFang SC','Hiragino Sans GB','Microsoft YaHei',sans-serif;
  font-size:17px;
  line-height:1.7;
  overflow-x:hidden;
  -webkit-font-smoothing:antialiased;
}

img{display:block;max-width:100%}
a{color:inherit;text-decoration:none}
p{margin:0 0 1em}
h1,h2,h3,h4{
  font-family:'Space Grotesk','Inter',system-ui,sans-serif;
  line-height:1.16;
  letter-spacing:-.02em;
  font-weight:600;
}

.shell{
  max-width:1180px;
  margin:0 auto;
  padding:18px clamp(14px,3vw,28px) 0;
}

/* ---------- 品牌行 ---------- */

.brandrow{
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap:12px;
  padding:4px 2px 16px;
  border-bottom:1px solid var(--line);
  margin-bottom:22px;
}

.brand{
  display:inline-flex;
  align-items:center;
  min-height:44px;
  padding:8px 2px;
  font-family:'Space Grotesk','Inter',sans-serif;
  font-weight:700;
  font-size:clamp(19px,2.6vw,25px);
  letter-spacing:.01em;
}

/* ---------- 主栅格 ---------- */

.layout{
  display:grid;
  grid-template-columns:minmax(0,1fr) 234px;
  gap:22px;
  align-items:start;
}

main{min-width:0}
main > article{
  background:var(--glass);
  -webkit-backdrop-filter:blur(18px) saturate(140%);
  backdrop-filter:blur(18px) saturate(140%);
  border:1px solid var(--line);
  border-radius:var(--r);
  box-shadow:var(--shadow);
  padding:clamp(20px,3.4vw,38px);
  margin:0 0 18px;
  scroll-margin-top:20px;
  transition:box-shadow .3s ease;
}
main > article:hover{box-shadow:var(--shadow-lift)}
main > article > :first-child{margin-top:0}
main > article > :last-child{margin-bottom:0}

/* ---------- 首屏 ---------- */

.hero{
  position:relative;
  min-height:70vh;
  display:grid;
  place-items:center;
  text-align:center;
  border-radius:40px;
  overflow:hidden;
  padding:clamp(24px,5vw,56px);
  background-color:#efefef;
  background-image:radial-gradient(rgba(31,31,31,.16) 1px,transparent 1px);
  background-size:22px 22px;
}

.hero-art{
  position:absolute;
  inset:0;
  margin:0;
  z-index:0;
}
.hero-art img{
  width:100%;
  height:100%;
  object-fit:cover;
  opacity:.92;
}

.hero-copy{
  position:relative;
  z-index:1;
  max-width:780px;
  padding:clamp(22px,4vw,46px);
  border-radius:32px;
  background:rgba(255,255,255,.66);
  -webkit-backdrop-filter:blur(16px);
  backdrop-filter:blur(16px);
  border:1px solid rgba(255,255,255,.8);
}

.hero-title{
  margin:0 0 14px;
  font-size:clamp(2rem,5.6vw,3.5rem);
  font-weight:700;
}

.hero-desc{
  margin:0;
  color:var(--muted);
  font-size:clamp(16px,1.9vw,19px);
  line-height:1.65;
}

/* ---------- 正文通用 ---------- */

main > article:not(.hero) h2{
  font-size:clamp(1.38rem,2.6vw,1.85rem);
  margin:.15em 0 .6em;
}
main > article:not(.hero) h3{
  font-size:1.18rem;
  margin:1.5em 0 .5em;
}
main > article ul,
main > article ol{
  padding-left:1.25em;
  margin:0 0 1.1em;
}
main > article li{margin:.35em 0}
main > article figure{margin:1.2em 0}
main > article img{border-radius:18px;height:auto}
main > article blockquote{
  margin:1.2em 0;
  padding:2px 0 2px 18px;
  border-left:3px solid var(--ink);
  color:var(--muted);
}
main > article table{
  width:100%;
  border-collapse:collapse;
  font-size:16px;
  margin:1.1em 0;
}
main > article th,
main > article td{
  border-bottom:1px solid var(--line);
  padding:10px 12px;
  text-align:left;
  vertical-align:top;
}
main > article th{font-weight:600;background:rgba(31,31,31,.04)}

strong{font-weight:600}
code{
  font-family:'JetBrains Mono',ui-monospace,monospace;
  font-size:.92em;
  background:rgba(31,31,31,.06);
  padding:2px 6px;
  border-radius:6px;
}

.eyebrow{
  display:block;
  margin:0 0 6px;
  font-family:'Inter',sans-serif;
  font-size:15px;
  font-weight:600;
  letter-spacing:.14em;
  color:var(--muted);
}

/* ---------- 右侧栏 ---------- */

.rail{
  position:sticky;
  top:18px;
  padding:18px 14px;
  border-radius:var(--r);
  border:1px solid var(--line);
  background:rgba(255,255,255,.62);
  -webkit-backdrop-filter:blur(20px) saturate(140%);
  backdrop-filter:blur(20px) saturate(140%);
  box-shadow:var(--shadow);
}

.rail-title{
  margin:0 0 14px;
  font-size:18px;
}

.rail-list{
  list-style:none;
  margin:0;
  padding:0;
  display:flex;
  flex-direction:column;
  gap:8px;
}

.pill{
  display:flex;
  align-items:center;
  min-height:44px;
  padding:10px 15px;
  border-radius:999px;
  border:1px solid var(--line);
  background:rgba(255,255,255,.85);
  font-size:16px;
  line-height:1.3;
  transition:transform .2s ease,background .2s ease,color .2s ease,border-color .2s ease;
}
.pill:hover{background:#fff;transform:translateX(2px)}
.pill.is-active{
  background:var(--ink);
  border-color:var(--ink);
  color:#fff;
}

/* ---------- 页脚 ---------- */

.site-foot{
  display:grid;
  grid-template-columns:1.5fr 1fr 1fr;
  gap:24px;
  margin-top:44px;
  padding-top:34px;
  border-top:1px solid var(--line);
}
.site-foot article{min-width:0}

.foot-word{
  margin:0;
  font-family:'Space Grotesk','Inter',sans-serif;
  font-weight:700;
  font-size:clamp(2.1rem,6.4vw,4.2rem);
  line-height:.98;
  letter-spacing:-.035em;
  word-break:break-all;
}

.foot-links h2,
.foot-note h2{
  font-size:18px;
  margin:0 0 12px;
}

.foot-list{
  list-style:none;
  margin:0;
  padding:0;
  display:flex;
  flex-direction:column;
  gap:2px;
}
.foot-link{
  display:flex;
  align-items:center;
  min-height:40px;
  padding:8px 0;
  font-size:16px;
  border-bottom:1px dashed var(--line);
}
.foot-link:hover{text-decoration:underline;text-underline-offset:4px}

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

.foot-base{
  grid-column:1/-1;
  margin-top:10px;
  padding:16px 0 30px;
  border-top:1px solid var(--line);
  color:var(--muted);
  font-size:15px;
}
.foot-base p{margin:0}

/* ---------- 滚入动效 ---------- */

.js [data-reveal]{
  opacity:0;
  transform:translateY(18px);
  transition:opacity .62s ease,transform .62s cubic-bezier(.2,.7,.2,1);
}
.js [data-reveal].in{
  opacity:1;
  transform:none;
}

/* ---------- 断点 ---------- */

@media (max-width:880px){
  .layout{
    grid-template-columns:minmax(0,1fr);
    gap:14px;
  }
  .rail{
    position:static;
    order:-1;
    padding:14px;
    border-radius:24px;
  }
  .rail-title{margin-bottom:10px;font-size:16px}
  .rail-list{
    flex-direction:row;
    overflow-x:auto;
    gap:8px;
    padding-bottom:4px;
    scrollbar-width:none;
  }
  .rail-list::-webkit-scrollbar{display:none}
  .pill{flex:0 0 auto;white-space:nowrap}
  .pill:hover{transform:translateY(-1px)}
  .hero{min-height:56vh;border-radius:32px}
  .site-foot{
    grid-template-columns:1fr;
    gap:18px;
  }
  .foot-link{min-height:44px}
}

@media (max-width:420px){
  body{font-size:16px}
  .hero-copy{border-radius:24px;padding:22px 18px}
  main > article{border-radius:24px;padding:20px 18px}
}

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

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