/* ============ ai2up design system ============ */
:root{
  --indigo:#6366f1;
  --cyan:#06b6d4;
  --green:#10b981;
  --amber:#f59e0b;
  --ink:#0f172a;
  --ink-2:#334155;
  --muted:#64748b;
  --line:#e6e8ee;
  --bg:#ffffff;
  --bg-alt:#f7f9fc;
  --grad:linear-gradient(120deg,#6366f1,#06b6d4);
  --grad-soft:linear-gradient(120deg,rgba(99,102,241,.10),rgba(6,182,212,.10));
  --shadow:0 18px 50px -20px rgba(15,23,42,.25);
  --radius:18px;
  --maxw:1160px;
  /* 系统字体栈：零网络请求，国内各平台均命中优质中英文字体 */
  --font:system-ui,-apple-system,'Segoe UI','PingFang SC','Hiragino Sans GB','Microsoft YaHei','Helvetica Neue',Helvetica,Arial,sans-serif;
}
*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth}
body{font-family:var(--font);color:var(--ink);background:var(--bg);line-height:1.65;-webkit-font-smoothing:antialiased}
img{max-width:100%;display:block}
a{color:inherit;text-decoration:none}
.container{max-width:var(--maxw);margin:0 auto;padding:0 24px}
.container--narrow{max-width:820px}
.sr-only{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0,0,0,0)}

/* ============ buttons ============ */
.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;font-weight:700;border-radius:999px;cursor:pointer;border:1px solid transparent;transition:transform .15s ease,box-shadow .2s ease,background .2s ease;font-family:inherit}
.btn--primary{background:var(--grad);color:#fff;box-shadow:0 12px 28px -10px rgba(99,102,241,.6)}
.btn--primary:hover{transform:translateY(-2px);box-shadow:0 18px 36px -12px rgba(99,102,241,.7)}
.btn--ghost{background:#fff;color:var(--ink);border-color:var(--line);box-shadow:var(--shadow)}
.btn--ghost:hover{transform:translateY(-2px);border-color:var(--indigo)}
.btn--lg{padding:15px 30px;font-size:16px}
.btn--sm{padding:9px 18px;font-size:14px}
.btn--block{width:100%}

/* ============ nav ============ */
.nav{position:sticky;top:0;z-index:50;background:rgba(255,255,255,.82);backdrop-filter:blur(12px);border-bottom:1px solid var(--line)}
.nav__inner{display:flex;align-items:center;justify-content:space-between;height:68px}
.brand{display:flex;align-items:center}
.nav__links{display:flex;align-items:center;gap:26px}
.nav__links a{font-size:15px;font-weight:500;color:var(--ink-2)}
.nav__links a:hover{color:var(--indigo)}
.nav__toggle{display:none;flex-direction:column;gap:5px;background:none;border:0;cursor:pointer;padding:8px}
.nav__toggle span{width:24px;height:2px;background:var(--ink);border-radius:2px;transition:.2s}

/* ============ hero ============ */
.hero{position:relative;overflow:hidden;padding:80px 0 70px}
.hero__bg{position:absolute;inset:0;background:
  radial-gradient(60% 60% at 80% 0%,rgba(6,182,212,.16),transparent 60%),
  radial-gradient(55% 55% at 10% 10%,rgba(99,102,241,.18),transparent 60%),
  var(--bg-alt)}
.hero__bg::after{content:"";position:absolute;inset:0;background-image:linear-gradient(rgba(15,23,42,.04) 1px,transparent 1px),linear-gradient(90deg,rgba(15,23,42,.04) 1px,transparent 1px);background-size:44px 44px;mask-image:radial-gradient(70% 70% at 50% 30%,#000,transparent)}
.hero__inner{position:relative;text-align:center;max-width:880px;margin:0 auto}
.pill{display:inline-flex;align-items:center;gap:8px;background:#fff;border:1px solid var(--line);border-radius:999px;padding:8px 16px;font-size:14px;font-weight:600;color:var(--ink-2);box-shadow:var(--shadow);margin-bottom:26px}
.pill__arrow{color:var(--indigo)}
.pill:hover .pill__arrow{transform:translateX(3px)}
.hero__title{font-size:clamp(38px,6vw,64px);line-height:1.08;font-weight:900;letter-spacing:-.02em;margin-bottom:22px}
.grad{background:var(--grad);-webkit-background-clip:text;background-clip:text;color:transparent}
.hero__sub{font-size:clamp(16px,2.2vw,20px);color:var(--ink-2);max-width:680px;margin:0 auto 34px}
.hero__sub strong{color:var(--ink)}
.hero__cta{display:flex;gap:14px;justify-content:center;flex-wrap:wrap;margin-bottom:54px}
.hero__stats{display:grid;grid-template-columns:repeat(4,1fr);gap:18px;background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:26px 18px;box-shadow:var(--shadow);max-width:760px;margin:0 auto}
.stat{text-align:center}
.stat__num{display:block;font-size:clamp(22px,3.2vw,30px);font-weight:900;color:var(--indigo)}
.stat__label{font-size:13px;color:var(--muted)}

/* ============ sections ============ */
.section{padding:84px 0}
.section--alt{background:var(--bg-alt)}
.section__head{text-align:center;max-width:720px;margin:0 auto 48px}
.eyebrow{display:inline-block;font-size:13px;font-weight:800;letter-spacing:.12em;text-transform:uppercase;color:var(--indigo);background:var(--grad-soft);padding:6px 14px;border-radius:999px;margin-bottom:16px}
.section__head h2{font-size:clamp(26px,3.6vw,40px);font-weight:900;letter-spacing:-.02em;line-height:1.2}
.section__lead{margin-top:14px;color:var(--muted);font-size:17px}

/* ============ grids ============ */
.grid{display:grid;gap:22px}
.grid--4{grid-template-columns:repeat(4,1fr)}
.grid--3{grid-template-columns:repeat(3,1fr)}

/* ============ audience cards ============ */
.card{background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:26px;transition:transform .2s ease,box-shadow .2s ease,border-color .2s ease}
.card:hover{transform:translateY(-5px);box-shadow:var(--shadow);border-color:transparent}
.card__icon{width:52px;height:52px;display:grid;place-items:center;font-size:26px;border-radius:14px;background:color-mix(in srgb,var(--c) 14%,#fff);margin-bottom:16px}
/* 人群卡图标配色（原内联 style，改为类以便缓存与 CSP 兼容） */
.ci--indigo{--c:#6366f1}
.ci--cyan{--c:#06b6d4}
.ci--green{--c:#10b981}
.ci--amber{--c:#f59e0b}
.card h3{font-size:19px;font-weight:800;margin-bottom:6px}
.card__pain{color:var(--muted);font-size:14px;margin-bottom:14px;min-height:42px}
.ticks{list-style:none;display:flex;flex-direction:column;gap:9px}
.ticks li{position:relative;padding-left:26px;font-size:14.5px;color:var(--ink-2)}
.ticks li::before{content:"✓";position:absolute;left:0;top:0;width:18px;height:18px;background:var(--green);color:#fff;border-radius:50%;font-size:11px;display:grid;place-items:center;font-weight:800}
.ticks--light li{color:#e2e8f0}
.ticks--light li::before{background:#fff;color:var(--green)}
/* 浅色背景上的清单（落地页订阅区），替代原先的内联 style */
.ticks--dark li{color:var(--ink-2)}

/* ============ features ============ */
.feature{background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:28px;transition:transform .2s,box-shadow .2s}
.feature:hover{transform:translateY(-4px);box-shadow:var(--shadow)}
.feature__no{font-size:14px;font-weight:900;color:var(--indigo);letter-spacing:.1em;margin-bottom:10px}
.feature h3{font-size:19px;font-weight:800;margin-bottom:8px}
.feature p{color:var(--muted);font-size:15px}

/* ============ resources ============ */
.resource{display:block;background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:26px;position:relative;transition:transform .2s,box-shadow .2s,border-color .2s}
.resource:hover{transform:translateY(-5px);box-shadow:var(--shadow);border-color:var(--indigo)}
.resource__tag{display:inline-block;font-size:12px;font-weight:800;color:#fff;background:var(--grad);padding:4px 10px;border-radius:999px;margin-bottom:14px}
.resource h3{font-size:18px;font-weight:800;margin-bottom:8px}
.resource p{color:var(--muted);font-size:14.5px;margin-bottom:16px}
.resource__link{color:var(--indigo);font-weight:700;font-size:14px}

/* ============ testimonials ============ */
.quote{background:#fff;border:1px solid var(--line);border-left:4px solid var(--indigo);border-radius:var(--radius);padding:26px}
.quote p{font-size:16px;color:var(--ink-2);margin-bottom:16px}
.quote footer{font-size:14px;color:var(--muted)}
.quote strong{color:var(--ink)}

/* ============ newsletter ============ */
.newsletter{padding:0 0 84px}
.newsletter__inner{background:var(--grad);border-radius:28px;padding:48px;display:grid;grid-template-columns:1.1fr 1fr;gap:40px;align-items:center;box-shadow:var(--shadow);color:#fff;position:relative;overflow:hidden}
.newsletter__inner::before{content:"";position:absolute;right:-60px;top:-60px;width:240px;height:240px;background:rgba(255,255,255,.12);border-radius:50%}
.newsletter__copy h2{font-size:clamp(26px,3.4vw,36px);font-weight:900;margin-bottom:12px}
.newsletter__copy p{opacity:.92;font-size:16px;margin-bottom:18px}
.newsletter__form{background:#fff;border-radius:18px;padding:24px;position:relative;z-index:1}
.newsletter__form input{width:100%;padding:14px 16px;border:1px solid var(--line);border-radius:12px;font-size:15px;font-family:inherit;margin-bottom:12px;outline:none}
.newsletter__form input:focus{border-color:var(--indigo)}
.form__hint{font-size:12.5px;color:var(--muted);text-align:center;margin-top:10px}
.form__ok{color:var(--green);font-weight:700;text-align:center;margin-top:10px;font-size:14px}

/* ============ faq ============ */
.faq{display:flex;flex-direction:column;gap:12px}
.faq__item{background:#fff;border:1px solid var(--line);border-radius:14px;padding:4px 20px;transition:border-color .2s}
.faq__item[open]{border-color:var(--indigo)}
.faq__item summary{cursor:pointer;font-weight:700;padding:16px 0;list-style:none;display:flex;justify-content:space-between;align-items:center}
.faq__item summary::-webkit-details-marker{display:none}
.faq__item summary::after{content:"+";font-size:22px;color:var(--indigo);font-weight:800}
.faq__item[open] summary::after{content:"−"}
.faq__item p{padding:0 0 18px;color:var(--muted)}

/* ============ about ============ */
.about__inner{display:grid;grid-template-columns:1.3fr 1fr;gap:44px;align-items:center}
.about__inner h2{font-size:clamp(24px,3.2vw,34px);font-weight:900;margin:14px 0 16px;line-height:1.25}
.about__inner p{color:var(--muted);font-size:16px}
.about__values{display:flex;flex-direction:column;gap:14px}
.value{background:#fff;border:1px solid var(--line);border-radius:14px;padding:18px 20px;display:flex;flex-direction:column}
.value strong{font-size:16px;color:var(--indigo)}
.value span{color:var(--muted);font-size:14px}

/* ============ footer ============ */
.footer{background:#0b1220;color:#cbd5e1;padding:60px 0 28px}
.footer__inner{display:grid;grid-template-columns:1.6fr 1fr 1fr 1fr;gap:30px}
.footer__brand img{margin-bottom:12px}
.footer__brand p{color:#94a3b8;font-size:14px}
.footer__col h4{color:#fff;font-size:15px;margin-bottom:14px}
.footer__col a{display:block;color:#94a3b8;font-size:14px;padding:5px 0}
.footer__col a:hover{color:#fff}
.footer__bottom{display:flex;justify-content:space-between;align-items:center;border-top:1px solid #1e293b;margin-top:40px;padding-top:22px;font-size:13px;color:#64748b;flex-wrap:wrap;gap:10px}
.footer__note{flex-basis:100%;font-size:12.5px;color:#475569;line-height:1.5}
.footer__links a{margin-left:18px;color:#64748b}
.footer__links a:hover{color:#fff}

/* ============ reveal animation ============ */
.reveal{opacity:0;transform:translateY(24px);transition:opacity .6s ease,transform .6s ease}
.reveal.in{opacity:1;transform:none}

/* ============ responsive ============ */
@media(max-width:980px){
  .grid--4{grid-template-columns:repeat(2,1fr)}
  .newsletter__inner{grid-template-columns:1fr;padding:36px}
  .about__inner{grid-template-columns:1fr}
  .footer__inner{grid-template-columns:1fr 1fr}
}
@media(max-width:680px){
  .nav__links{position:fixed;inset:68px 0 auto 0;background:#fff;border-bottom:1px solid var(--line);flex-direction:column;align-items:stretch;gap:0;padding:10px 24px 20px;transform:translateY(-120%);transition:transform .3s ease;box-shadow:var(--shadow)}
  .nav__links.open{transform:none}
  .nav__links a{padding:12px 0;border-bottom:1px solid var(--line)}
  .nav__toggle{display:flex}
  .hero__stats{grid-template-columns:repeat(2,1fr);gap:14px}
  .grid--4,.grid--3{grid-template-columns:1fr}
  .footer__inner{grid-template-columns:1fr}
  .section{padding:60px 0}
  .hero{padding:54px 0 50px}
}

/* ============ 平台能力 capability cards ============ */
.cap-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:22px;align-items:start}
.cap{border:1px solid var(--line);border-radius:18px;background:#fff;overflow:hidden;display:flex;flex-direction:column;box-shadow:0 18px 50px -30px rgba(15,23,42,.35);transition:transform .2s,box-shadow .2s,border-color .2s}
.cap:hover{transform:translateY(-4px);box-shadow:0 24px 56px -30px rgba(15,23,42,.45);border-color:transparent}
.cap__shot{height:120px;background:repeating-linear-gradient(45deg,#eef1f7,#eef1f7 10px,#e7ebf3 10px,#e7ebf3 20px);display:grid;place-items:center;color:var(--muted);font-size:13px;border-bottom:1px solid var(--line)}
.cap__shot span{background:#fff;border:1px dashed #c7cedb;padding:6px 12px;border-radius:8px}
.cap__body{padding:20px;display:flex;flex-direction:column;gap:12px;flex:1}
.cap__tag{display:inline-block;font-size:11.5px;font-weight:800;color:#fff;background:var(--grad);padding:3px 10px;border-radius:999px;align-self:flex-start}
.cap__title{font-size:18px;font-weight:900;letter-spacing:-.01em;margin:0}
.cap__row{font-size:13.5px;line-height:1.55}
.cap__row .k{font-weight:800;color:var(--muted);display:block;font-size:11px;letter-spacing:.06em;text-transform:uppercase;margin-bottom:2px}
.cap__row.pain .v{color:var(--ink-2)}
.cap__row .v{color:var(--ink)}
.cap__row.proof .v{color:var(--green);font-weight:700}
.chips{display:flex;flex-wrap:wrap;gap:8px;margin-top:2px}
.chips span{background:var(--grad-soft);border:1px solid var(--line);border-radius:999px;padding:5px 12px;font-size:12.5px;color:var(--ink-2)}
.cap__cta{margin-top:auto;display:inline-flex;align-items:center;justify-content:center;gap:6px;color:#fff;background:var(--grad);font-weight:800;font-size:14px;padding:11px 16px;border-radius:12px}
.cap__cta:hover{filter:brightness(1.05);color:#fff}
@media(max-width:980px){.cap-grid{grid-template-columns:repeat(2,1fr)}}
@media(max-width:680px){.cap-grid{grid-template-columns:1fr}}