/* ════════════════════════════════════════════════════════════════════
   LEMMA WEB SYSTEM v1.0 — monochrome
   首页 / 子页共用。设计文档见 design-guide/Lemma-Website-Style-Guide.html
   ════════════════════════════════════════════════════════════════════ */

/* ── 1. TOKENS ─────────────────────────────────────────────────────── */
:root{
  --ink:#0A0A0B;
  --text:#2B2B30;
  --mut:#6E6E77;
  --mut-2:#9C9CA4;

  --bg:#FFFFFF;
  --surface:#F4F4F6;
  --surface-2:#E9E9EC;
  --surface-3:#1A1A1C;

  --paper-a:#FCFCFB;
  --paper-b:#F4F3F1;

  --hair:rgba(10,10,11,.10);
  --hair-2:rgba(10,10,11,.055);

  --glow-core:rgba(10,10,11,.12);
  --glow-mid:rgba(10,10,11,.05);
  --glow-none:rgba(10,10,11,0);
  --lift-core:rgba(255,255,255,.55);

  --grain:.055;

  --serif:"Newsreader",Georgia,"Noto Serif SC","Source Han Serif SC","Songti SC","Noto Serif CJK SC",serif;
  --sans:"Inter","Noto Sans SC","PingFang SC","Microsoft YaHei","Noto Sans CJK SC",-apple-system,BlinkMacSystemFont,"Helvetica Neue",Arial,sans-serif;
  --mono:"JetBrains Mono",ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;

  --max:680px;
  --max-wide:980px;
  --max-nav:1080px;

  --pad-act:clamp(64px,8vw,120px);
  --pad-interlude:clamp(72px,9vw,140px);
  --pad-compact:clamp(40px,6vw,72px);

  --r-sm:10px;
  --r-md:18px;
  --r-lg:22px;
  --r-pill:999px;

  --sh-paper:0 1px 2px rgba(20,15,40,.04),0 14px 40px -22px rgba(20,15,40,.16);
  --sh-sheet:0 32px 90px rgba(20,15,40,.10),0 4px 16px rgba(20,15,40,.05);
  --sh-nav:inset 0 -1px 1px rgba(10,10,11,.05),0 2px 8px rgba(10,10,11,.04),0 14px 44px -18px rgba(10,10,11,.18);
  --sh-mark:0 12px 44px rgba(10,10,11,.28),0 3px 14px rgba(10,10,11,.14);
  --sh-photo:0 18px 60px -24px rgba(20,15,40,.35),0 4px 14px rgba(20,15,40,.06);

  --ease:cubic-bezier(.23,1,.32,1);
  --ease-out:cubic-bezier(.16,1,.3,1);

  --fs-mark:clamp(44px,13vw,148px);
  --fs-h-xl:clamp(38px,6.5vw,72px);
  --fs-h-lg:clamp(28px,4.6vw,42px);
  --fs-stat:clamp(26px,4.4vw,38px);
  --fs-lede:clamp(20px,2.2vw,28px);
  --fs-body:17.5px;
  --fs-text:16.5px;
  --fs-sm:15.5px;
  --fs-k:13px;
}

*,*::before,*::after{box-sizing:border-box}
html,body,h1,h2,h3,h4,p,dl,dd,dt,figure,blockquote,ul,ol,li{margin:0;padding:0}
html{scroll-behavior:smooth;color-scheme:light;-webkit-text-size-adjust:100%;-webkit-tap-highlight-color:transparent}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}}

body{
  background:var(--bg);color:var(--text);
  font-family:var(--sans);font-weight:400;
  font-size:var(--fs-body);line-height:1.6;
  -webkit-font-smoothing:antialiased;
  overflow-x:clip;
}
::selection{background:rgba(10,10,11,.12);color:var(--ink)}
a{color:inherit;text-decoration:none}
ul,ol{list-style:none}
img,svg,video{max-width:100%;display:block}

:is(a,button):focus-visible{outline:2px solid var(--ink);outline-offset:3px;border-radius:4px}

h1,h2,h3,h4{color:var(--ink)}
h1,h2,.statement{text-wrap:balance}
p{text-wrap:pretty}
img,svg,video{max-width:100%}

.wrap{max-width:var(--max);margin:0 auto;padding:0 24px}
.wrap--wide{max-width:var(--max-wide)}

.k{font-size:var(--fs-k);letter-spacing:.14em;text-transform:uppercase;color:var(--mut);margin:0 0 16px;font-weight:500;font-family:var(--sans)}

h2{font-family:var(--serif);font-weight:400;font-size:var(--fs-h-lg);line-height:1.18;letter-spacing:-.015em;margin:0 0 24px}

section[id],.story[id]{scroll-margin-top:76px}

/* ── 2. 胶片颗粒 ───────────────────────────────────────────────────── */
.grain{position:relative;isolation:isolate}
.grain::before{
  content:"";position:absolute;inset:0;pointer-events:none;z-index:0;
  background-image:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='160' height='160'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='2' stitchTiles='stitch'/%3E%3CfeColorMatrix type='saturate' values='0'/%3E%3CfeComponentTransfer%3E%3CfeFuncA type='linear' slope='0.055'/%3E%3C/feComponentTransfer%3E%3C/filter%3E%3Crect width='160' height='160' filter='url(%23n)'/%3E%3C/svg%3E");
}
.grain>*{position:relative;z-index:1}

/* ── 3. 液态玻璃导航 ───────────────────────────────────────────────── */
.nav{position:sticky;top:0;z-index:50;padding:0 16px}
.nav__in{
  max-width:var(--max-nav);margin:0 auto;padding:10px 12px 10px 22px;
  display:flex;align-items:center;gap:28px;
  border-radius:var(--r-pill);position:relative;
  background:linear-gradient(120deg,rgba(255,255,255,.88),rgba(255,255,255,.68) 45%,rgba(255,255,255,.84));
  -webkit-backdrop-filter:blur(22px) saturate(1.4);
  backdrop-filter:blur(22px) saturate(1.4);
  box-shadow:var(--sh-nav);
}
.nav__in::after{
  content:"";position:absolute;inset:0;border-radius:var(--r-pill);pointer-events:none;
  background:linear-gradient(100deg,transparent 30%,rgba(255,255,255,.5) 44%,transparent 58%);
  opacity:.55;
}
@supports not ((backdrop-filter:blur(1px)) or (-webkit-backdrop-filter:blur(1px))){
  .nav__in{background:rgba(255,255,255,.94)}
}
.brand{font-family:var(--sans);font-weight:600;font-size:20px;letter-spacing:-.02em;color:var(--ink);
  display:inline-flex;align-items:center;gap:9px}
.brand__mark{width:18px;height:18px;display:inline-block;color:var(--ink);flex:0 0 18px;
  transform:translateY(-1px)}  /* 微抬，与 20px 字号的光学对齐 */
.nav__links{display:flex;gap:24px;margin-left:auto;align-items:center}
.nav__links a{font-size:14.5px;color:var(--mut);text-decoration:none;transition:color 150ms ease}
.nav__links a:not(.nav__cta):not(.lang){padding:14px 4px;margin:-14px -4px}
.nav__links a:hover{color:var(--ink)}
.nav__links a.is-active{color:var(--ink);font-weight:500}
.nav__links .lang{border:1px solid var(--hair);border-radius:var(--r-pill);padding:5px 11px;font-size:13px;color:var(--mut);font-weight:500;margin:0 2px;transition:color 150ms ease,border-color 150ms ease,background 150ms ease}
.nav__links .lang:hover{color:var(--ink);border-color:var(--ink);background:rgba(10,10,11,.03)}
@media(max-width:900px){.nav__links .lang{display:inline-block !important}}
.nav__cta{
  background:var(--ink);color:#fff !important;padding:8px 18px;border-radius:var(--r-pill);
  font-weight:500;white-space:nowrap;transition:transform 160ms var(--ease),opacity 150ms ease;
}
@media(hover:hover) and (pointer:fine){.nav__cta:hover{opacity:.85}}
.nav__cta:active{transform:scale(.97)}
@media(max-width:900px){.nav__links a:not(.nav__cta){display:none}}
@media(max-width:480px){.nav__in{gap:14px;padding:8px 10px 8px 16px}.brand{font-size:18px}.nav__cta{font-size:13px;padding:11px 14px}}

/* ── 4. 巨型字标 ───────────────────────────────────────────────────── */
.wordmark{
  position:relative;left:-.02em;
  font-family:var(--serif);font-weight:300;
  font-size:var(--fs-mark);line-height:1.02;letter-spacing:-.03em;
  margin:0 0 40px;
  -webkit-text-stroke:.75px currentColor;
}

/* ── 5. 陈述级排版 ─────────────────────────────────────────────────── */
.statement{font-family:var(--serif);font-weight:400;font-size:var(--fs-stat);line-height:1.14;letter-spacing:-.015em;max-width:600px;margin:0 auto 14px}
.statement em{font-style:italic}
.oneliner{font-family:var(--sans);font-weight:500;font-size:var(--fs-lede);line-height:1.4;letter-spacing:-.025em;max-width:56ch;text-wrap:balance;margin:0 auto 42px}

/* ── 6. 玻璃 CTA ───────────────────────────────────────────────────── */
.glassbtn{
  position:relative;display:inline-flex;align-items:center;justify-content:center;
  height:54px;padding:0 34px;overflow:hidden;border:0;border-radius:var(--r-pill);
  color:rgba(255,255,255,.94);text-decoration:none;cursor:pointer;
  font-family:var(--sans);font-size:16.5px;font-weight:500;letter-spacing:-.01em;
  transition:box-shadow 220ms var(--ease);
  will-change:transform;
}
.glassbtn::before,.glassbtn::after{content:"";position:absolute;inset:0;border-radius:inherit}
.glassbtn::before{background:rgba(10,10,11,.89);box-shadow:inset 2px 4px 16px rgba(255,255,255,.06)}
.glassbtn::after{z-index:2;border:1px solid rgba(255,255,255,.25);opacity:.25;pointer-events:none;
  -webkit-mask-image:linear-gradient(170deg,#000,transparent 50%);
  mask-image:linear-gradient(170deg,#000,transparent 50%)}
.glassbtn__title{position:relative;z-index:4}
.glassbtn__circle{position:absolute;z-index:3;top:calc(50% - 100px);left:calc(50% - 100px);width:200px;height:200px}
.glassbtn__circle::before,.glassbtn__circle::after{content:"";position:absolute;inset:0;border-radius:50%}
.glassbtn__circle::before{
  background:conic-gradient(from 180deg,rgba(255,255,255,.012) 180deg,rgba(255,255,255,.06) 360deg);
  filter:blur(15px);animation:glassbtn-circle 3.6s linear infinite;transition:opacity .5s}
.glassbtn__circle::after{inset:30px;background:rgba(255,255,255,.14);opacity:0;filter:blur(5px);
  transform:scale(.5);transition:opacity .5s,transform .7s;
  -webkit-mask-image:radial-gradient(50% 50%,#000,rgba(23,23,23,0));
  mask-image:radial-gradient(50% 50%,#000,rgba(23,23,23,0))}
.glassbtn--lift{box-shadow:var(--sh-mark)}
@media(hover:hover) and (pointer:fine){.glassbtn:hover{box-shadow:0 16px 56px rgba(10,10,11,.32),0 3px 14px rgba(10,10,11,.14)}}
.glassbtn:hover .glassbtn__circle::before{opacity:0}
.glassbtn:hover .glassbtn__circle::after{opacity:1;transform:scale(1)}
.glassbtn:active{box-shadow:var(--sh-mark) inset, 0 6px 18px rgba(10,10,11,.28)}
@keyframes glassbtn-circle{
  0%{transform:translate(0) rotate(0)}
  25%{transform:translateX(-30px) rotate(90deg)}
  50%{transform:translate(0) rotate(180deg)}
  75%{transform:translateX(30px) rotate(270deg)}
  100%{transform:translate(0) rotate(360deg)}}
@media(prefers-reduced-motion:reduce){.glassbtn__circle::before{animation:none}}

.pill{
  display:inline-block;padding:11px 22px;border-radius:var(--r-pill);
  background:var(--ink);color:#fff !important;font-size:15px;font-weight:500;text-decoration:none;
  transition:box-shadow 220ms var(--ease),opacity 150ms ease;
  will-change:transform;
}
.pill--ghost{background:transparent;color:var(--ink) !important;border:1px solid var(--hair)}
@media(hover:hover) and (pointer:fine){.pill:hover{opacity:.86}}
.pill:active{box-shadow:0 6px 18px rgba(10,10,11,.28) inset}

/* 磁吸容器：内层按钮由 JS 跟随鼠标 */
.magnetic{display:inline-block;position:relative}
.magnetic>.glassbtn,.magnetic>.pill{transition:box-shadow 220ms var(--ease)}

/* ── 7. 纸卡 ───────────────────────────────────────────────────────── */
.paper{
  background:linear-gradient(180deg,var(--paper-a),var(--paper-b));
  border-radius:var(--r-lg);padding:28px 26px 26px;
  box-shadow:var(--sh-paper);
  transition:transform .45s var(--ease),box-shadow .45s var(--ease);
}
@media(hover:hover) and (pointer:fine){
  .paper:hover{transform:translateY(-4px);
    box-shadow:0 4px 12px rgba(20,15,40,.06),0 28px 50px -22px rgba(20,15,40,.22)}
  .paper:hover .tag{background:var(--ink);color:#fff}
  .paper:hover svg{transform:scale(1.04)}
  .paper:hover svg [stroke]{stroke-opacity:1}
}
.tcard{min-height:340px;display:flex;flex-direction:column}
.tcard .tag{display:inline-block;width:max-content;margin:24px 0 12px;font-size:11.5px;letter-spacing:.12em;
  padding:5px 11px;border-radius:var(--r-pill);background:rgba(10,10,11,.05);color:var(--mut);
  font-weight:500;text-transform:uppercase;
  transition:background .3s var(--ease),color .3s var(--ease)}
.tcard svg{transition:transform .5s var(--ease)}
.tcard svg [stroke]{transition:stroke-opacity .3s var(--ease)}
.tflip{display:flex;align-items:baseline;gap:9px;flex-wrap:wrap;margin:18px 0 10px;
  font-family:var(--serif);font-size:22px;font-weight:400;color:var(--ink);line-height:1.25;letter-spacing:-.01em}
.tflip .tarrow{font-family:var(--sans);font-size:14px;color:var(--mut)}
.tcard p{font-size:var(--fs-text);line-height:1.7;color:var(--text)}

.trio{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:20px;max-width:var(--max-wide);margin:0 auto}
@media(max-width:820px){.trio{grid-template-columns:1fr}.tcard{min-height:0}.tflip{margin:16px 0 8px}}

/* ── 8. sheet 纸面 ────────────────────────────────────────────────── */
.sheet{position:relative;background:linear-gradient(180deg,var(--paper-a),var(--paper-b));
  border-radius:var(--r-sm);padding:56px 52px 46px;box-shadow:var(--sh-sheet);margin:44px -40px 52px}
.sheet::before{content:"";position:absolute;inset:0;border-radius:var(--r-sm);pointer-events:none;opacity:.4;
  background-image:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='160' height='160'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='2' stitchTiles='stitch'/%3E%3CfeColorMatrix type='saturate' values='0'/%3E%3CfeComponentTransfer%3E%3CfeFuncA type='linear' slope='0.055'/%3E%3C/feComponentTransfer%3E%3C/filter%3E%3Crect width='160' height='160' filter='url(%23n)'/%3E%3C/svg%3E")}
.sheet>*{position:relative}
.sheet p{font-size:17px;line-height:1.78;margin-bottom:18px}
@media(max-width:760px){.sheet{padding:36px 26px 32px;margin:36px -10px 44px}}

/* ── 9. 光晕岛 + 反转 slab ─────────────────────────────────────────── */
.isle{position:relative;isolation:isolate;overflow:hidden;background:var(--bg)}
.isle::before{
  content:"";position:absolute;inset:0;z-index:-1;pointer-events:none;
  background-image:
    url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='160' height='160'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='2' stitchTiles='stitch'/%3E%3CfeColorMatrix type='saturate' values='0'/%3E%3CfeComponentTransfer%3E%3CfeFuncA type='linear' slope='0.05'/%3E%3C/feComponentTransfer%3E%3C/filter%3E%3Crect width='160' height='160' filter='url(%23n)'/%3E%3C/svg%3E"),
    radial-gradient(50% 46% at 50% 46%,var(--glow-core) 0%,var(--glow-mid) 42%,var(--glow-none) 78%);
  -webkit-mask-image:radial-gradient(58% 52% at 50% 46%,#000 30%,transparent 78%);
  mask-image:radial-gradient(58% 52% at 50% 46%,#000 30%,transparent 78%);
  animation:breathe 12s ease-in-out infinite alternate;
}
@keyframes breathe{from{opacity:.72}to{opacity:1}}
@media(prefers-reduced-motion:reduce){.isle::before{animation:none}}

.slab{position:relative;overflow:hidden;background:var(--surface-3);color:rgba(255,255,255,.88)}
.slab h2{color:#fff}
.slab .k{color:rgba(255,255,255,.55)}
.slab p{color:rgba(255,255,255,.72)}
.slab::before{content:"";position:absolute;inset:0;pointer-events:none;
  background:radial-gradient(46% 50% at 50% 40%,var(--lift-core),transparent 72%);opacity:.7}

/* ── 10. 入场揭示 ─────────────────────────────────────────────────── */
.rise{opacity:0;transform:translateY(10px);animation:rise .6s var(--ease) forwards}
@keyframes rise{to{opacity:1;transform:none}}

.sr>.wrap>*,.story.sr>*{opacity:0;transform:translateY(12px);
  transition:opacity .55s var(--ease),transform .55s var(--ease)}
.sr.in>.wrap>*,.story.sr.in>*{opacity:1;transform:none}
.sr.in>.wrap>*:nth-child(2),.story.sr.in>*:nth-child(2){transition-delay:60ms}
.sr.in>.wrap>*:nth-child(3),.story.sr.in>*:nth-child(3){transition-delay:120ms}
.sr.in>.wrap>*:nth-child(4),.story.sr.in>*:nth-child(4){transition-delay:180ms}
.sr.in>.wrap>*:nth-child(5),.story.sr.in>*:nth-child(5){transition-delay:240ms}
.sr.in>.wrap>*:nth-child(6),.story.sr.in>*:nth-child(6){transition-delay:300ms}
.sr.in>.wrap>*:nth-child(n+7),.story.sr.in>*:nth-child(n+7){transition-delay:360ms}
@media(prefers-reduced-motion:reduce){
  .rise{transform:none;animation:fadeonly .5s ease forwards}
  .sr>.wrap>*,.story.sr>*{transform:none;transition:opacity .3s ease}
}
@keyframes fadeonly{from{opacity:0}to{opacity:1}}

.skip{position:absolute;left:-9999px}
.skip:focus{left:16px;top:12px;background:#fff;padding:8px 12px;z-index:99}

/* ════════════════════════════════════════════════════════════════════
   以下为首页/子页章节级样式，模板之上长出来的部分。
   ════════════════════════════════════════════════════════════════════ */

/* Hero —— 一台安静的聚光灯舞台 + 品牌几何水印 */
.stage{position:relative}
.hero{
  position:sticky;top:0;z-index:0;isolation:isolate;
  min-height:calc(100svh - 0px);
  display:grid;align-content:center;
  padding:clamp(120px,15vh,170px) 0 clamp(72px,9vh,110px);
  text-align:center;overflow:clip;
}
.hero .wrap{max-width:1020px;position:relative;z-index:1}
.hero__mark{
  position:absolute;left:50%;top:50%;
  width:clamp(260px,34vw,440px);height:auto;
  transform:translate(-50%,-58%);
  color:rgba(10,10,11,.085);pointer-events:none;
  z-index:0;transition:transform .6s var(--ease-out);
  will-change:transform;
}
.hero__mark svg{width:100%;height:auto;display:block;overflow:visible}
@media(max-width:640px){.hero__mark{width:200px;opacity:.07}}
.hero::before{
  content:"";position:absolute;left:50%;top:6%;width:min(1560px,128vw);
  aspect-ratio:16/10;transform:translateX(-50%);z-index:-1;pointer-events:none;
  background:radial-gradient(50% 46% at 50% 38%,
    rgba(10,10,11,.085) 0%,rgba(10,10,11,.028) 48%,rgba(10,10,11,0) 76%);
  animation:heroglow 11s ease-in-out infinite alternate;
}
@keyframes heroglow{from{opacity:.7}to{opacity:1}}
@media(prefers-reduced-motion:reduce){.hero::before{animation:none;opacity:1}}
.hero__attr{color:var(--mut);font-size:13px;letter-spacing:.16em;text-transform:uppercase;margin:38px 0 0;font-weight:500}
.hero__lede{max-width:760px;margin:0 auto 14px}
.hero__sub{max-width:560px;margin:0 auto 44px;color:var(--text)}

/* 关键短语下划线扫过（IO 触发） */
.mark{
  display:inline;background-image:linear-gradient(currentColor,currentColor);
  background-size:0 2px;background-repeat:no-repeat;background-position:0 100%;
  padding-bottom:2px;transition:background-size 1.1s var(--ease-out);
  color:inherit;
}
.mark.in{background-size:100% 2px}
@media(prefers-reduced-motion:reduce){
  .mark{background-size:100% 2px;transition:none}
}

/* Mission：满屏冷灰层 */
.mission{min-height:100svh;display:grid;align-content:center;text-align:center;padding:var(--pad-act) 0;position:relative;overflow:hidden;
  border-radius:clamp(20px,3vw,32px) clamp(20px,3vw,32px) 0 0;
  box-shadow:0 -30px 70px -40px rgba(20,15,40,.35)}
.mission .wrap{max-width:960px}
.mission h2{font-size:var(--fs-h-xl);line-height:1.08;letter-spacing:-.025em;max-width:900px;margin:0 auto 36px}
.mission-quote{margin:34px auto 0;max-width:760px;color:var(--ink);
  font-family:var(--sans);font-weight:500;font-size:var(--fs-lede);line-height:1.4;letter-spacing:-.025em;text-wrap:balance}
.mission-attr{display:block;margin-top:18px;font-style:normal;font-size:14.5px;color:var(--mut);font-weight:500}

/* 创始人 —— 编辑式双人档案：插画肖像，无框融入页面 */
.founders{padding:var(--pad-act) 0 0}
.sr.founders>*{opacity:0;transition:opacity .6s var(--ease)}
.sr.founders.in>*{opacity:1}
.sr.founders.in>*:nth-child(2){transition-delay:140ms}
@media(prefers-reduced-motion:reduce){.sr.founders>*{opacity:1;transition:none}}
.founders__head{max-width:880px;margin:0 auto;padding:0 24px;text-align:left}
.founders__head .k{margin-bottom:12px}
.founders__head h2{font-size:clamp(32px,4.8vw,52px);line-height:1.06;letter-spacing:-.025em;max-width:15em}
.founders__list{max-width:880px;margin:clamp(40px,6vw,72px) auto 0;padding:0 24px}
.fpair{
  display:grid;grid-template-columns:minmax(0,320px) minmax(0,1fr);
  gap:clamp(30px,5vw,72px);align-items:center;
  padding:clamp(36px,5vw,64px) 0;
}
.fpair + .fpair{border-top:1px solid var(--hair-2)}
.fpair__photo{
  position:relative;aspect-ratio:4/5;border-radius:var(--r-md);
  background:transparent;box-shadow:none;
  grid-column:1;grid-row:1;min-width:0;
}
.fpair__photo img{
  width:100%;height:100%;object-fit:cover;object-position:50% 22%;
  border-radius:var(--r-md);
  transition:transform .8s var(--ease);
}
@media(hover:hover) and (pointer:fine){
  .fpair:hover .fpair__photo img{transform:scale(1.015)}
}
@media(prefers-reduced-motion:reduce){
  .fpair__photo img{transition:none}
  .fpair:hover .fpair__photo img{transform:none}
}
.fpair__bio{grid-column:2;grid-row:1;min-width:0}
.fpair--flip .fpair__photo{grid-column:2}
.fpair--flip .fpair__bio{grid-column:1}
.fpair__bio .name{font-family:var(--serif);font-weight:400;font-size:clamp(32px,3.8vw,46px);
  line-height:1.04;letter-spacing:-.025em;color:var(--ink);margin:0 0 12px}
.fpair__bio .role{font-family:var(--mono);font-size:11px;letter-spacing:.16em;text-transform:uppercase;
  color:var(--mut);margin:0 0 22px}
.fpair__bio .text{font-size:var(--fs-text);line-height:1.8;color:var(--text);max-width:48ch}
.fpair__bio .text a{text-decoration:underline;text-underline-offset:3px;text-decoration-thickness:1px}
.fpair__bio .text a:hover{color:var(--ink)}
.fpair__bio .links{display:flex;gap:8px;flex-wrap:wrap;margin-top:22px}
.fpair__bio .links a{font-family:var(--mono);font-size:11px;letter-spacing:.08em;color:var(--mut);
  border:1px solid var(--hair);border-radius:var(--r-pill);padding:6px 13px;transition:color 150ms ease,border-color 150ms ease}
.fpair__bio .links a:hover{color:var(--ink);border-color:var(--ink)}
@media(max-width:820px){
  .fpair{grid-template-columns:1fr;gap:22px;padding:32px 0}
  .fpair>*,.fpair--flip .fpair__photo,.fpair--flip .fpair__bio{grid-column:1;grid-row:auto}
  .fpair__photo{max-width:400px;width:100%}
  .fpair__bio .text{max-width:none}
  .fpair .fpair__photo{order:-1}
  .founders__head h2{max-width:none}
}

/* Building */
.building{padding-top:clamp(72px,9vw,120px);padding-bottom:clamp(56px,7vw,88px);background:var(--surface-2)}
.building h2{font-size:var(--fs-h-xl);line-height:1.08;letter-spacing:-.025em;max-width:900px;margin:0 auto 36px;text-align:center}
.building .intro{max-width:560px;margin:0 auto 56px;color:var(--text);font-size:var(--fs-text);line-height:1.7;text-align:center}

.feature-icon{height:120px;display:flex;align-items:center;justify-content:center}
.feature-icon svg{width:auto;height:88px;display:block}

/* Waitlist（深色 slab） */
.waitlist{padding:var(--pad-act) 0 160px;text-align:center}
.waitlist h2{font-size:var(--fs-h-xl);line-height:1.08;letter-spacing:-.025em;margin-bottom:32px}
.waitlist>p{max-width:560px;margin:0 auto 8px}
.waitlist-card{
  margin:8px auto 0;max-width:640px;background:#FFFFFF;
  border-radius:var(--r-lg);padding:clamp(28px,4vw,48px);
  box-shadow:0 30px 90px -30px rgba(0,0,0,.6),0 10px 30px -18px rgba(0,0,0,.4);
  text-align:left;
}
.waitlist-card iframe{width:100%;border:0;display:block;background:transparent;height:740px}
.waitlist-card .waitlist-alt{
  margin:22px 0 0;font-size:13.5px;color:var(--mut);text-align:center;line-height:1.6}
.waitlist-card .waitlist-alt a{
  text-decoration:underline;text-underline-offset:3px;text-decoration-thickness:1px;
  color:var(--text);transition:color 150ms ease}
.waitlist-card .waitlist-alt a:hover{color:var(--ink)}
@media(max-width:640px){.waitlist-card{padding:22px 14px}.waitlist-card iframe{height:820px}}

/* Letter */
.letter{padding:clamp(40px,5vw,64px) 0 clamp(48px,6vw,72px)}
.letter h2{font-size:var(--fs-h-xl);line-height:1.08;letter-spacing:-.025em;margin-bottom:24px;text-align:center}
.letter .sheet p{font-family:var(--sans);font-size:16.5px;line-height:1.82;color:var(--text)}
.letter .sheet p.lede{font-family:var(--serif);font-size:20px;line-height:1.5;color:var(--ink);letter-spacing:-.01em}
.letter .sig{font-family:var(--serif);font-style:normal;font-weight:500;font-size:26px;letter-spacing:-.01em;margin-top:34px;color:var(--ink)}
.letter .sig span{display:block;font-family:var(--sans);font-style:normal;margin-top:6px;font-weight:500;font-size:14px;letter-spacing:.05em;color:var(--mut);text-transform:uppercase}

/* Facts */
.facts{padding:var(--pad-act) 0}
.facts h2{font-size:var(--fs-h-xl);line-height:1.08;letter-spacing:-.025em;margin-bottom:32px}
.facts dl{display:grid;gap:22px;margin:8px 0 0}
.facts .row{display:grid;grid-template-columns:210px 1fr;gap:18px;align-items:baseline}
.facts dt{font-size:var(--fs-k);letter-spacing:.1em;text-transform:uppercase;color:var(--mut);padding-top:3px;font-weight:500}
.facts dd{margin:0;font-size:var(--fs-text);line-height:1.7}
.facts dd a{text-decoration:underline;text-underline-offset:3px;text-decoration-thickness:1px;transition:color 150ms ease}
.facts dd a:hover{color:var(--ink)}
@media(max-width:560px){.facts .row{grid-template-columns:1fr;gap:4px}}

/* Hiring */
.hiring{padding:var(--pad-act) 0;text-align:center}
.hiring h2{font-size:var(--fs-h-xl);line-height:1.08;letter-spacing:-.025em;margin-bottom:24px}
.hiring p{max-width:560px;margin:0 auto 36px;color:var(--text)}

/* Community */
.community{padding:var(--pad-compact) 0;text-align:center}
.community h2{font-family:var(--serif);font-size:var(--fs-h-lg);margin-bottom:24px}
.community .links{display:flex;gap:14px;justify-content:center;flex-wrap:wrap;margin-top:24px}

/* Footer */
footer.site{padding:48px 0 56px;color:var(--mut);font-size:14.5px;position:relative;overflow-x:clip}
footer.site .wrap{display:flex;justify-content:space-between;gap:16px;flex-wrap:wrap}
footer.site a{color:var(--mut);display:inline-block;padding:10px 4px;margin:-10px -4px;text-decoration:none;transition:color 150ms ease}
footer.site a:hover{color:var(--ink)}
footer.site .legal{color:var(--mut-2);font-size:12.5px;letter-spacing:.02em}

/* 极光页脚（中性灰阶版本） */
.aurora{position:absolute;left:0;right:0;bottom:0;height:560px;z-index:-1;pointer-events:none;
  transform:scaleY(0);transform-origin:bottom;opacity:.9;
  transition:transform 1.3s var(--ease-out)}
.sr.in .aurora{transform:scaleY(1)}
.aurora svg{width:100%;height:100%;display:block;transform-origin:bottom;
  animation:aurorabreathe 9s ease-in-out infinite}
@keyframes aurorabreathe{
  0%{transform:scaleY(.96) translateX(-.5%) scaleX(1.01)}
  50%{transform:scaleY(1.05) translateX(.5%) scaleX(1.01)}
  100%{transform:scaleY(.96) translateX(-.5%) scaleX(1.01)}}
@media(max-width:640px){.aurora{height:320px}}
@media(prefers-reduced-motion:reduce){
  .aurora{transform:none;transition:none}
  .aurora svg{animation:none}
}

/* 平板 */
@media(max-width:900px){
  .hero{padding:120px 0 64px;display:grid;align-content:center}
}