:root{
  --bg:#f7f7f8;
  --ink:#15171a;
  --muted:#6d7279;
  /* 次级文字色：原来的 #858a91 对白底只有 3.1:1，未达 WCAG AA 4.5:1
     ——下面的值约为 5.2:1，页面内所有小号灰字都请用它。 */
  --muted2:#666d75;
  /* 只用于深色背景上的小字 */
  --muted-dark:#8e959d;
  --line:#e5e7eb;
  --red:#d92f36;
  --red2:#ff5057;
  --dark:#111418;
  --card:#ffffff;
  --soft:#f1f3f5;
  --shadow:0 18px 60px rgba(15,18,22,.08);
  --focus:#0b62d6;
  /* 系统字体栈：覆盖中文（Win/mac/移动）与西文，零网络请求、零 FOIT */
  --font-ui:-apple-system,BlinkMacSystemFont,"Segoe UI Variable Text","Segoe UI","Inter",
    "PingFang SC","HarmonyOS Sans SC","MiSans","Source Han Sans SC","Noto Sans SC",
    "Microsoft YaHei UI","Microsoft YaHei",Roboto,"Helvetica Neue",Arial,sans-serif;
}
*{box-sizing:border-box}
html{
  scroll-behavior:smooth;
  /* sticky 头部 76px，锚点跳转时留余量，避免标题被压在导航栏下面 */
  scroll-padding-top:96px;
}
body{
  margin:0;
  color:var(--ink);
  background:#fff;
  font-family:var(--font-ui);
  line-height:1.65;
}
a{text-decoration:none;color:inherit}

/* ---- 键盘可达性 ---- */
/* 无鼠标用户必须能看见焦点在哪里；不用 :focus 以免鼠标点击也画框 */
:focus-visible{
  outline:3px solid var(--focus);
  outline-offset:3px;
  border-radius:6px;
}
/* 深色区块里蓝色描边看不见，改用白色 */
.dark-section :focus-visible,
.download-section :focus-visible,
footer :focus-visible,
.institution-title :focus-visible,
.lab-callout :focus-visible{
  outline-color:#fff;
}
.skip-link{
  position:fixed;left:16px;top:-120px;z-index:200;
  background:#fff;color:var(--ink);font-size:14px;font-weight:600;
  padding:12px 18px;border-radius:10px;border:1px solid #ccd0d5;
  box-shadow:0 10px 30px rgba(0,0,0,.12);transition:top .18s ease;
}
.skip-link:focus{top:14px}
@media(prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  *,*::before,*::after{
    animation-duration:.001ms!important;
    animation-iteration-count:1!important;
    transition-duration:.001ms!important;
  }
}
.site-header{
  position:sticky;top:0;z-index:50;
  background:rgba(255,255,255,.9);
  backdrop-filter:blur(18px);
  border-bottom:1px solid rgba(0,0,0,.06);
}
.nav-wrap{
  max-width:1440px;margin:auto;padding:0 34px;height:76px;
  display:flex;align-items:center;gap:30px;
}
.brand{display:flex;align-items:center;gap:10px;min-width:215px}
.brand-mark{
  width:42px;height:42px;border-radius:12px;background:#111418;color:#fff;
  display:grid;place-items:center;font-size:22px;font-weight:800;letter-spacing:-2px;
}
.brand-mark span{color:var(--red)}
.brand-text{display:flex;flex-direction:column;line-height:1.05}
.brand-text strong{font-size:19px}
.brand-text small{font-size:10px;color:var(--muted2);margin-top:5px;letter-spacing:.3px}
nav{display:flex;align-items:center;gap:22px;flex:1;justify-content:center}
nav a{font-size:14px;color:#34383e;font-weight:600}
nav a:hover,nav .lab-link{color:var(--red)}
.nav-actions{display:flex;align-items:center;gap:14px}
.text-btn{font-size:14px;font-weight:600}
.primary-btn,.secondary-btn{
  display:inline-flex;align-items:center;justify-content:center;
  min-height:48px;padding:0 22px;border-radius:10px;font-weight:700;font-size:14px;
  transition:.2s;
}
.primary-btn{background:var(--red);color:#fff;box-shadow:0 10px 28px rgba(217,47,54,.2)}
.primary-btn:hover{transform:translateY(-1px);background:#c5252c}
.primary-btn.small{min-height:40px;padding:0 16px;font-size:13px}
.secondary-btn{border:1px solid #ccd0d5;background:#fff}
.secondary-btn:hover{border-color:#989da4}
/* ---- 移动端菜单开关（checkbox hack，无 JS 可用）---- */
/* checkbox 本体隐藏但保持可聚焦，键盘 Tab + Space 即可开合 */
.nav-toggle{
  position:absolute;width:1px;height:1px;margin:0;opacity:0;
}
/* 桌面端菜单常显，开关纯属多余——移出渲染树，避免多一个无意义的 Tab 停靠点 */
@media(min-width:1051px){ .nav-toggle{display:none} }
.menu-btn{
  display:none;background:none;border:0;padding:6px 4px;
  font-size:25px;line-height:1;color:var(--ink);cursor:pointer;
}
.menu-btn::before{content:"☰"}
.nav-toggle:checked ~ .menu-btn::before{content:"✕"}
/* 焦点画在可见的 label 上，而不是那个看不见的 checkbox */
.nav-toggle:focus-visible ~ .menu-btn{
  outline:3px solid var(--focus);outline-offset:3px;border-radius:8px;
}
.hero{
  overflow:hidden;
  background:
    radial-gradient(circle at 85% 18%, rgba(217,47,54,.10), transparent 25%),
    linear-gradient(180deg,#fff 0%,#fbfbfc 100%);
}
.hero-grid{
  min-height:700px;max-width:1440px;margin:auto;padding:85px 34px 70px;
  display:grid;grid-template-columns:.95fr 1.05fr;gap:65px;align-items:center;
}
.eyebrow{text-transform:uppercase;letter-spacing:1.7px;font-size:12px;font-weight:800;color:var(--red);margin-bottom:16px}
.hero h1{
  margin:0;font-size:clamp(46px,5.3vw,76px);line-height:1.08;letter-spacing:-3px;font-weight:850;
}
.hero h1 span{display:block;color:var(--red)}
.hero-lead{font-size:18px;color:#555b63;max-width:720px;margin:25px 0 30px}
.hero-actions{display:flex;gap:14px;flex-wrap:wrap}
.hero-meta{display:flex;gap:34px;margin-top:42px}
.hero-meta div{display:flex;flex-direction:column}
.hero-meta b{font-size:14px}
.hero-meta span{font-size:12px;color:var(--muted2)}
.hero-panel{
  border:1px solid #e3e5e8;background:#fff;border-radius:20px;box-shadow:var(--shadow);overflow:hidden;
  transform:perspective(1400px) rotateY(-2deg) rotateX(1deg);
}
.panel-top{height:48px;background:#f4f5f6;border-bottom:1px solid #e5e6e8;display:flex;align-items:center;padding:0 18px;gap:7px}
.dot{width:10px;height:10px;border-radius:50%}.dot.red{background:#ff6058}.dot.yellow{background:#ffbd2e}.dot.green{background:#28c840}
.panel-title{font-size:12px;color:#6e737a;margin-left:10px}
.workspace{padding:18px;background:#fafafa}
.chart-card,.ai-card{background:#fff;border:1px solid #e8e9eb;border-radius:14px;padding:16px}
.chart-card{margin-bottom:14px}
.chart-label{font-size:12px;color:#747980;margin-bottom:8px}
.axis{fill:none;stroke:#d7dade;stroke-width:1}
.curve{fill:none;stroke:#d92f36;stroke-width:2.3}
.curve-fill{fill:url(#fill1);stroke:none}
.ai-head{display:flex;gap:10px;align-items:center}
.ai-icon{width:36px;height:36px;border-radius:10px;background:#111418;color:#fff;display:grid;place-items:center;font-size:11px;font-weight:800}
.ai-head div:last-child{display:flex;flex-direction:column}.ai-head small{font-size:10px;color:var(--muted2)}
.user-msg{margin:14px 0;background:#f1f2f4;border-radius:10px;padding:12px 14px;font-size:13px}
.ai-steps{display:grid;grid-template-columns:1fr 1fr;gap:7px;font-size:11px;color:#4c5259}
.ai-result{margin-top:14px;border-left:3px solid var(--red);padding:8px 12px;font-size:12px;color:#51565d;background:#fff8f8}
.trust-strip{border-top:1px solid #eee;border-bottom:1px solid #eee;background:#fff}
.trust-inner{max-width:1200px;margin:auto;padding:20px 30px;display:flex;justify-content:space-between;gap:20px;color:var(--muted2);font-size:13px}
.section{max-width:1320px;margin:auto;padding:105px 34px}
.section-head{max-width:850px;margin-bottom:48px}
.section-head h2,.lab-grid h2,.security-grid h2,.download-section h2{
  margin:0 0 16px;font-size:clamp(34px,4vw,52px);line-height:1.12;letter-spacing:-1.7px
}
.section-head p,.lead{font-size:17px;color:#666d75;margin:0}
.feature-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:18px}
.feature-card{border:1px solid var(--line);border-radius:16px;padding:28px;min-height:220px;background:#fff}
.feature-card:hover{box-shadow:0 18px 50px rgba(0,0,0,.06);transform:translateY(-2px);transition:.25s}
.feature-card .num{font-size:12px;color:var(--red);font-weight:800}
.feature-card h3{font-size:20px;margin:48px 0 10px}
.feature-card p{font-size:14px;color:#6d7278;margin:0}
.dark-section{max-width:none;background:#111418;color:#fff}
.dark-section .section-head,.dark-section .flow-wrap,.dark-section .quote-panel{max-width:1320px;margin-left:auto;margin-right:auto}
.section-head.light p{color:#aeb4bb}
.flow-wrap{display:grid;grid-template-columns:1fr auto 1fr auto 1fr auto 1fr auto 1fr;gap:12px;align-items:center}
.flow-item{border:1px solid #34383e;background:#181c21;border-radius:15px;padding:22px;min-height:160px}
.flow-item b{font-size:11px;color:#ff686e}
.flow-item strong{display:block;font-size:16px;margin:18px 0 8px}
.flow-item span{font-size:12px;color:#9ea5ad}
.flow-arrow{color:var(--muted-dark);font-size:22px}
.quote-panel{margin-top:40px!important;border:1px solid #2e3238;border-radius:15px;padding:26px;text-align:center;color:#f0f1f2;font-size:20px}
.lab-section{padding-top:120px;padding-bottom:120px}
.lab-grid{display:grid;grid-template-columns:1fr 1fr;gap:70px;align-items:center}
.red-text{color:var(--red)}
.lab-points{margin-top:34px;display:grid;gap:18px}
.lab-points div{display:grid;grid-template-columns:42px 1fr;gap:14px;align-items:start}
.lab-points span{width:38px;height:38px;border-radius:10px;background:#fff1f1;color:var(--red);font-weight:800;display:grid;place-items:center;font-size:12px}
.lab-points p{margin:0;color:#666d75;font-size:14px}.lab-points b{color:#25292e}
.lab-diagram{
  min-height:520px;border-radius:26px;background:
    radial-gradient(circle at center,rgba(217,47,54,.08),transparent 38%),
    #f8f8f9;border:1px solid #e8e9eb;position:relative;overflow:hidden;
}
.lab-diagram:before,.lab-diagram:after{
  content:"";position:absolute;left:50%;top:50%;transform:translate(-50%,-50%);border:1px dashed #d7dade;border-radius:50%;
}
.lab-diagram:before{width:360px;height:360px}.lab-diagram:after{width:500px;height:500px}
.lab-core{
  position:absolute;left:50%;top:47%;transform:translate(-50%,-50%);z-index:2;
  width:185px;height:185px;border-radius:50%;background:#111418;color:white;display:grid;place-items:center;text-align:center;font-size:26px;font-weight:800;box-shadow:0 20px 50px rgba(0,0,0,.18)
}
.lab-core span{display:block;font-size:10px;font-weight:500;color:#bfc4ca;margin-top:-55px}
.orbit{position:absolute;z-index:3;background:#fff;border:1px solid #e0e2e5;box-shadow:0 8px 25px rgba(0,0,0,.06);border-radius:11px;padding:10px 14px;font-size:12px;font-weight:700}
.o1{left:8%;top:15%}.o2{right:10%;top:17%}.o3{left:6%;top:52%}.o4{right:7%;top:48%}.o5{left:18%;bottom:18%}.o6{right:12%;bottom:17%}
.lab-loop{position:absolute;bottom:18px;left:20px;right:20px;z-index:5;background:#fff;border:1px solid #e1e3e6;border-radius:11px;padding:10px 12px;display:flex;justify-content:center;gap:8px;font-size:11px}
.lab-loop i{font-style:normal;color:var(--red)}
.lab-callout{margin-top:46px;background:#111418;color:#fff;border-radius:18px;padding:28px 34px;display:grid;grid-template-columns:1fr 1fr;gap:40px;align-items:center}
.lab-callout small{color:#ff777c;font-weight:700}.lab-callout strong{display:block;font-size:22px;margin-top:5px}.lab-callout p{margin:0;color:#b8bec5;font-size:14px}
.soft-section{max-width:none;background:#f5f6f7}
.soft-section>*{max-width:1320px;margin-left:auto;margin-right:auto}
.video-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:20px}
.video-card{background:#fff;border:1px solid #e5e7ea;border-radius:16px;padding:16px}
.video-cover{height:220px;border-radius:11px;background:linear-gradient(135deg,#20242a,#3f444c);display:grid;place-items:center;position:relative;color:#fff}
.video-cover span{width:60px;height:60px;border-radius:50%;background:rgba(255,255,255,.14);display:grid;place-items:center;font-size:24px}
.video-cover b{position:absolute;right:12px;bottom:10px;font-size:11px;background:#111418;padding:3px 7px;border-radius:5px}
.video-card h3{margin:18px 0 7px}.video-card p{font-size:13px;color:#747980;margin:0}
.video-note{text-align:center;color:var(--muted2);font-size:12px;margin-top:20px}
.case-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:18px}
.case-card{border:1px solid #e5e6e8;border-radius:16px;padding:26px}
.case-card span{font-size:11px;color:var(--muted2);font-weight:800}.case-card h3{font-size:21px;margin:40px 0 10px}.case-card p{font-size:13px;color:#72777d}
.case-card.accent{background:#fff7f7;border-color:#f1c5c7}.case-card.accent span{color:var(--red)}
.institution-card{border:1px solid #e2e4e7;border-radius:22px;overflow:hidden}
.institution-title{padding:28px 32px;background:#111418;color:#fff}
.institution-title small{color:#ff6d73;font-size:11px;letter-spacing:1px}.institution-title h3{margin:5px 0 0;font-size:27px}
.team-grid{display:grid;grid-template-columns:1fr 1fr}
.team-grid article{padding:36px}.team-grid article+article{border-left:1px solid #eceef0}
.avatar{width:58px;height:58px;border-radius:16px;background:#f0f1f3;display:grid;place-items:center;font-weight:800;color:#383d43}
.team-grid h4{font-size:23px;margin:22px 0 5px}.tags{font-size:12px;color:var(--red)!important;font-weight:700}.team-grid p{font-size:14px;color:#696f76}
.team-slogan{border-top:1px solid #eceef0;padding:22px 32px;text-align:center;font-weight:700}
.account-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:16px}
.account-grid article{border:1px solid #e5e7e9;border-radius:15px;padding:24px}
.acc-icon{width:36px;height:36px;border-radius:9px;background:#111418;color:#fff;display:grid;place-items:center;font-size:11px;font-weight:700}
.account-grid h3{font-size:17px;margin:28px 0 8px}.account-grid p{font-size:13px;color:#70767d}
.credits-flow{margin-top:28px;border-radius:13px;background:#f4f5f6;padding:18px 20px;display:flex;justify-content:center;gap:12px;flex-wrap:wrap;font-size:12px;font-weight:700}
.credits-flow i{font-style:normal;color:var(--red)}
.account-note{margin-top:18px;font-size:13px;color:#61676d}
.security-grid{display:grid;grid-template-columns:1fr 1fr;gap:70px;align-items:center}
.security-list{display:grid;grid-template-columns:1fr 1fr;gap:12px}
.security-list div{background:#fff;border:1px solid #e5e7ea;border-radius:12px;padding:18px;font-size:13px;font-weight:700}
.timeline{display:grid;grid-template-columns:1fr auto 1fr auto 1fr auto 1fr auto 1fr auto 1fr;gap:12px;align-items:center}
.timeline div{border:1px solid #e2e4e7;border-radius:14px;padding:18px;min-height:110px}
.timeline b{display:block;font-size:14px}.timeline span{display:block;font-size:11px;color:var(--muted2);margin-top:7px}.timeline i{font-style:normal;color:#8a9199}.timeline .active{border-color:#efc3c5;background:#fff6f6}.timeline .future{background:#111418;color:#fff}.timeline .future span{color:#bfc4ca}
.faq-list{max-width:920px}
details{border-bottom:1px solid #e1e3e6;padding:20px 0}
summary{cursor:pointer;font-weight:700;font-size:16px}
details p{color:#6c7279;font-size:14px;max-width:820px}
.download-section{background:var(--red);color:#fff}
.download-inner{max-width:1320px;margin:auto;padding:70px 34px;display:flex;justify-content:space-between;align-items:center;gap:40px}
/* 原来的 #ffd5d6 / #ffe1e2 在品牌红底上只有 3.5–3.9:1，达不到 AA；改用纯白约 4.8:1 */
.download-section .eyebrow{color:#fff}.download-section p{color:#fff}
.light-btn{background:#fff;color:#c7282e;box-shadow:none}.light-btn:hover{background:#fff}
.dark-outline{background:transparent;border-color:rgba(255,255,255,.5);color:#fff}
footer{background:#0e1013;color:#fff}
.footer-grid{max-width:1320px;margin:auto;padding:55px 34px;display:grid;grid-template-columns:2fr 1fr 1fr 1fr;gap:40px}
.footer-brand{font-size:25px;font-weight:800}.footer-grid p{font-size:12px;color:#8d949c}.footer-grid b{font-size:13px;margin-bottom:12px;display:block}.footer-grid a{display:block;font-size:12px;color:#9da4ac;margin:8px 0}
.footer-bottom{max-width:1320px;margin:auto;border-top:1px solid #24282e;padding:18px 34px 26px;display:flex;justify-content:space-between;color:#747b83;font-size:11px}
@media(max-width:1050px){
  .nav-actions{display:none}nav{display:none}.menu-btn{display:block;margin-left:auto}
  /* 用兄弟选择器代替原来的 .open 类——checkbox 状态即菜单状态，JS 挂了也能开 */
  .nav-toggle:checked ~ nav{
    position:absolute;left:0;right:0;top:76px;z-index:60;
    background:#fff;display:flex;flex-direction:column;align-items:stretch;
    padding:12px 34px 20px;border-bottom:1px solid #eee;
    box-shadow:0 18px 40px rgba(15,18,22,.10);
    max-height:calc(100vh - 76px);overflow:auto;
  }
  .nav-toggle:checked ~ nav a{
    padding:12px 2px;font-size:16px;border-bottom:1px solid #f1f2f4;
  }
  .nav-toggle:checked ~ nav a:last-child{border-bottom:0}
  .hero-grid,.lab-grid,.security-grid{grid-template-columns:1fr}
  .hero-grid{padding-top:60px}.hero-panel{transform:none}
  .feature-grid{grid-template-columns:repeat(2,1fr)}
  .flow-wrap{grid-template-columns:1fr}.flow-arrow{transform:rotate(90deg);text-align:center}
  .account-grid{grid-template-columns:repeat(2,1fr)}
  .timeline{display:flex;flex-wrap:wrap}.timeline i{display:none}.timeline div{flex:1 1 28%}
}
@media(max-width:700px){
  .nav-wrap{padding:0 18px}.brand-text small{display:none}.brand{min-width:auto}
  .hero-grid,.section{padding-left:20px;padding-right:20px}
  .hero h1{font-size:46px;letter-spacing:-2px}.hero-lead{font-size:16px}
  .hero-meta{flex-direction:column;gap:10px}
  .trust-inner{flex-direction:column}
  .feature-grid,.video-grid,.case-grid,.team-grid,.account-grid,.security-list{grid-template-columns:1fr}
  .team-grid article+article{border-left:0;border-top:1px solid #eceef0}
  .lab-callout{grid-template-columns:1fr}
  .lab-diagram{min-height:560px}.lab-diagram:after{width:420px;height:420px}.lab-diagram:before{width:300px;height:300px}
  .o1{left:5%;top:12%}.o2{right:5%;top:14%}.o3{left:5%;top:42%}.o4{right:5%;top:44%}.o5{left:6%;bottom:24%}.o6{right:5%;bottom:24%}
  .lab-loop{font-size:9px;gap:5px}
  .download-inner{flex-direction:column;align-items:flex-start}
  .footer-grid{grid-template-columns:1fr 1fr}.footer-bottom{flex-direction:column;gap:6px}
}