/* 知己AI marketing — quiet, warm, generous. Light and dark, three languages. */
:root{
  --bg:#f7f8fb; --bg-2:#f0f3f8; --panel:#ffffff; --line:rgba(20,27,45,.11); --line-2:rgba(20,27,45,.18);
  --fg:#12141a; --fg-2:#5d6472; --fg-3:#8a92a2; --inv:#ffffff; --ink:#12141a;
  --accent:#0a84ff; --accent-soft:rgba(10,132,255,.10);
  --shadow:0 1px 2px rgba(20,27,45,.05),0 12px 40px rgba(20,27,45,.08);
  --max:1080px; --ease:cubic-bezier(.16,.84,.44,1);
  --font:"PingFang SC","Microsoft YaHei","Hiragino Sans GB","Noto Sans SC",ui-sans-serif,-apple-system,BlinkMacSystemFont,"Segoe UI",system-ui,sans-serif;
  --serif:"Songti SC","Noto Serif SC",Georgia,"Times New Roman",serif;
}
:root[data-theme="dark"]{
  --bg:#0b0d12; --bg-2:#12151c; --panel:#161a22; --line:rgba(255,255,255,.10); --line-2:rgba(255,255,255,.18);
  --fg:#f2f4f8; --fg-2:#a8b0bf; --fg-3:#78808f; --inv:#0b0d12; --ink:#f2f4f8;
  --accent:#3d9bff; --accent-soft:rgba(61,155,255,.14);
  --shadow:0 1px 2px rgba(0,0,0,.4),0 24px 70px rgba(0,0,0,.5);
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
html,body{margin:0;padding:0}
body{background:var(--bg);color:var(--fg);font-family:var(--font);-webkit-font-smoothing:antialiased;overflow-x:hidden;font-size:16px;line-height:1.6}
a{color:inherit;text-decoration:none}
img{max-width:100%;display:block}
.wrap{max-width:var(--max);margin:0 auto;padding:0 28px}
h1,h2,h3{margin:0;font-weight:500;letter-spacing:-.025em;line-height:1.12}
p{margin:0;color:var(--fg-2)}
.eyebrow{font-size:11.5px;letter-spacing:.18em;text-transform:uppercase;color:var(--fg-3);font-weight:600}

/* reveal */
.rise{opacity:0;transform:translateY(14px);transition:opacity .7s var(--ease),transform .7s var(--ease)}
.rise.in{opacity:1;transform:none}
@media (prefers-reduced-motion:reduce){.rise{opacity:1;transform:none;transition:none}}

/* nav */
.nav{position:sticky;top:0;z-index:60;background:color-mix(in srgb,var(--bg) 84%,transparent);backdrop-filter:saturate(180%) blur(18px)}
.nav-in{display:flex;align-items:center;gap:28px;height:64px}
.brand{display:flex;align-items:center;gap:9px;font-weight:600;font-size:16px;letter-spacing:-.01em}
.mark{width:26px;height:26px;border-radius:8px;display:block}
.nav-links{display:flex;gap:26px;font-size:14.5px;color:var(--fg-2)}
.nav-links a{position:relative;padding:2px 0}
.nav-links a::after{content:"";position:absolute;left:0;right:100%;bottom:-2px;height:1px;background:var(--fg);transition:right .35s var(--ease)}
.nav-links a:hover{color:var(--fg)}
.nav-links a:hover::after{right:0}
.nav-cta{margin-left:auto;display:flex;align-items:center;gap:8px}
.btn{display:inline-flex;align-items:center;justify-content:center;height:38px;padding:0 18px;border-radius:10px;font-size:14.5px;font-weight:500;border:1px solid transparent;cursor:pointer;transition:.18s var(--ease);font-family:inherit;white-space:nowrap}
.btn-ghost{color:var(--fg-2);border-color:var(--line-2);background:transparent}
.btn-ghost:hover{color:var(--fg);border-color:var(--fg-3)}
.btn-solid{background:var(--ink);color:var(--inv)}
.btn-solid:hover{transform:translateY(-1px);box-shadow:var(--shadow)}
.btn-accent{background:var(--accent);color:#fff}
.btn-accent:hover{transform:translateY(-1px);box-shadow:var(--shadow);opacity:.94}
.btn-lg{height:50px;padding:0 28px;border-radius:12px;font-size:15.5px}
.icon-btn{width:36px;height:36px;border-radius:10px;border:1px solid transparent;background:transparent;color:var(--fg-3);display:grid;place-items:center;cursor:pointer;transition:.18s}
.icon-btn:hover{color:var(--fg);background:var(--bg-2)}
.icon-btn svg{width:17px;height:17px;fill:none;stroke:currentColor;stroke-width:1.7;stroke-linecap:round;stroke-linejoin:round}
:root[data-theme="dark"] .sun{display:none}
:root:not([data-theme="dark"]) .moon{display:none}
.lang{position:relative}
.lang-menu{position:absolute;right:0;top:44px;background:var(--panel);border:1px solid var(--line);border-radius:12px;padding:6px;box-shadow:var(--shadow);display:none;min-width:132px}
.lang.open .lang-menu{display:block}
.lang-menu a{display:block;padding:8px 12px;border-radius:8px;font-size:14px;color:var(--fg-2)}
.lang-menu a:hover{background:var(--bg-2);color:var(--fg)}

/* hero */
.hero{position:relative;padding:120px 0 96px;text-align:center;overflow:hidden}
.hero::before{content:"";position:absolute;left:50%;top:-320px;width:1100px;height:700px;transform:translateX(-50%);
  background:radial-gradient(closest-side,var(--accent-soft),transparent 72%);pointer-events:none}
.hero-in{position:relative}
h1{font-size:clamp(40px,6.4vw,74px);font-weight:500}
h1 em{font-style:normal;font-family:var(--serif);font-weight:400;color:var(--accent)}
.hero p.sub{margin:26px auto 0;max-width:560px;font-size:clamp(16px,2vw,18.5px);line-height:1.7}
.hero-cta{display:flex;gap:12px;justify-content:center;margin-top:36px;flex-wrap:wrap}

/* model line */
.models{display:flex;justify-content:center;flex-wrap:wrap;gap:8px;margin-top:34px}
.models span{display:inline-flex;align-items:center;gap:7px;font-size:13px;color:var(--fg-2);border:1px solid var(--line);border-radius:999px;padding:6px 14px 6px 8px;background:var(--panel)}
.models img{width:17px;height:17px;border-radius:4px;flex-shrink:0}

/* prompt box */
.ask{margin:38px auto 0;max-width:620px;border:1px solid var(--line-2);border-radius:16px;background:var(--panel);box-shadow:var(--shadow);
  display:flex;align-items:center;gap:14px;padding:16px 16px 16px 20px;text-align:left;transition:.25s var(--ease)}
.ask:hover{transform:translateY(-2px);border-color:var(--fg-3)}
.ask .txt{flex:1;min-width:0;font-size:16px;color:var(--fg-2);white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.ask .caret{display:inline-block;width:1.5px;height:19px;background:var(--accent);vertical-align:-3px;margin-left:1px;animation:blink 1.1s steps(1) infinite}
@keyframes blink{50%{opacity:0}}
.ask .go{width:36px;height:36px;border-radius:10px;background:var(--ink);color:var(--inv);display:grid;place-items:center;flex-shrink:0}
.ask .go svg{width:16px;height:16px;fill:none;stroke:currentColor;stroke-width:2;stroke-linecap:round;stroke-linejoin:round}

/* marquee */
.marquee{margin-top:74px;position:relative;overflow:hidden;mask-image:linear-gradient(90deg,transparent,#000 12%,#000 88%,transparent);-webkit-mask-image:linear-gradient(90deg,transparent,#000 12%,#000 88%,transparent)}
.marquee-row{display:flex;gap:10px;width:max-content;animation:slide 46s linear infinite}
.marquee-row:nth-child(2){animation-duration:58s;animation-direction:reverse;margin-top:10px}
.marquee:hover .marquee-row{animation-play-state:paused}
@keyframes slide{to{transform:translateX(-50%)}}
.tag{display:inline-flex;align-items:center;gap:8px;border:1px solid var(--line);background:var(--panel);border-radius:10px;padding:8px 14px 8px 10px;font-size:13.5px;color:var(--fg-2);white-space:nowrap}
.tag img{width:18px;height:18px;border-radius:4px;flex-shrink:0}
@media (prefers-reduced-motion:reduce){.marquee-row{animation:none}}

/* sections */
section{padding:110px 0}
.sec-head{max-width:640px}
.sec-head h2{font-size:clamp(28px,3.8vw,42px);margin-top:14px;font-weight:500}
.sec-head p{margin-top:16px;font-size:17px;line-height:1.75}
.center{margin-left:auto;margin-right:auto;text-align:center}

/* feature rows */
.rows{margin-top:64px;display:grid;gap:1px;background:var(--line);border-top:1px solid var(--line);border-bottom:1px solid var(--line)}
.row{background:var(--bg);display:grid;grid-template-columns:180px 1fr;gap:40px;padding:34px 4px}
.row h3{font-size:19px;font-weight:500}
.row p{margin-top:10px;font-size:15.5px;max-width:620px}
.row .k{font-size:13.5px;color:var(--fg-3);letter-spacing:.02em;padding-top:3px}

/* steps */
.steps{margin-top:60px;display:grid;grid-template-columns:repeat(4,1fr);gap:28px}
.step{position:relative;padding-top:26px}
.step::before{content:"";position:absolute;left:0;top:0;width:100%;height:1px;background:var(--line)}
.step::after{content:"";position:absolute;left:0;top:-3.5px;width:7px;height:7px;border-radius:4px;background:var(--accent)}
.step b{display:block;font-size:12px;color:var(--fg-3);letter-spacing:.12em;margin-bottom:10px}
.step h3{font-size:16.5px;font-weight:500;margin-bottom:8px}
.step p{font-size:14.5px}

/* numbers */
.nums{margin-top:60px;display:grid;grid-template-columns:repeat(4,1fr);gap:32px}
.num b{display:block;font-size:44px;font-weight:400;letter-spacing:-.03em;font-family:var(--serif);line-height:1}
.num span{display:block;margin-top:10px;font-size:14px;color:var(--fg-3)}

/* chips */
.chips{display:flex;flex-wrap:wrap;gap:8px;margin-top:28px}
.chips span{border:1px solid var(--line);border-radius:8px;padding:7px 13px;font-size:13.5px;color:var(--fg-2);background:var(--panel)}

/* made-with-it gallery */
.made{margin-top:56px;display:grid;grid-template-columns:repeat(auto-fit,minmax(232px,1fr));gap:26px}
.made-card{display:block;color:inherit;text-decoration:none}
.made-card .shot{border:1px solid var(--line);border-radius:14px;overflow:hidden;background:var(--panel);aspect-ratio:4/3;box-shadow:var(--shadow);transition:transform .5s var(--ease),border-color .3s}
.made-card .shot img{width:100%;height:100%;object-fit:cover;object-position:top center;display:block}
a.made-card:hover .shot{transform:translateY(-4px);border-color:var(--line-2)}
.made-k{margin-top:16px;font-size:12px;letter-spacing:.12em;color:var(--fg-3)}
.made-card h3{margin-top:7px;font-size:17px;font-weight:500}
.made-card p{margin-top:7px;font-size:14.5px;color:var(--fg-2);line-height:1.65}
.made-go{display:inline-block;margin-top:10px;font-size:14px;color:var(--accent)}
.made-go::after{content:" \2197"}

/* pricing */
.plans{display:grid;grid-template-columns:repeat(4,1fr);gap:0;margin-top:60px;border:1px solid var(--line);border-radius:16px;overflow:hidden}
.plan{padding:30px 26px;display:flex;flex-direction:column;border-right:1px solid var(--line);background:var(--bg)}
.plan:last-child{border-right:0}
.plan.on{background:var(--panel)}
.tier{font-size:14px;font-weight:600;letter-spacing:.02em}
.price{margin:16px 0 0;font-size:34px;font-weight:400;letter-spacing:-.03em;font-family:var(--serif)}
.price small{font-size:13.5px;color:var(--fg-3);font-family:var(--font)}
.plan ul{margin:20px 0 0;padding:0;list-style:none;display:grid;gap:10px}
.plan li{font-size:13.5px;color:var(--fg-2);line-height:1.5}
.plan .foot{margin-top:auto;padding-top:26px}
.plan .foot .btn{width:100%}

/* faq */
.faq{margin-top:52px;border-top:1px solid var(--line)}
.faq details{border-bottom:1px solid var(--line);padding:22px 0}
.faq summary{cursor:pointer;font-size:17px;font-weight:500;list-style:none;display:flex;align-items:center;justify-content:space-between;gap:24px}
.faq summary::-webkit-details-marker{display:none}
.faq summary::after{content:"";width:9px;height:9px;border-right:1.5px solid var(--fg-3);border-bottom:1.5px solid var(--fg-3);transform:rotate(45deg) translateY(-2px);transition:transform .2s var(--ease);flex-shrink:0}
.faq details[open] summary::after{transform:rotate(-135deg) translateY(-2px)}
.faq p{margin-top:14px;font-size:15.5px;max-width:760px}

.cta{text-align:center;padding:130px 0}
.cta h2{font-size:clamp(30px,4.6vw,48px);font-weight:500}
.cta p{margin:18px auto 0;max-width:480px;font-size:17px}

footer{border-top:1px solid var(--line);padding:52px 0 64px;color:var(--fg-3);font-size:13.5px}
.foot{display:flex;gap:52px;flex-wrap:wrap;align-items:flex-start}
.foot-col{display:grid;gap:10px}
.foot-col b{color:var(--fg-2);font-weight:600;font-size:13px}
.foot-col a:hover{color:var(--fg)}
.foot-end{margin-top:40px;display:flex;justify-content:space-between;gap:16px;flex-wrap:wrap;padding-top:24px;border-top:1px solid var(--line)}

@media(max-width:900px){
  .nav-links{display:none}
  .row{grid-template-columns:1fr;gap:10px;padding:28px 2px}
  .steps,.nums{grid-template-columns:repeat(2,1fr);gap:26px}
  .made{grid-template-columns:repeat(2,1fr);gap:22px}
  .plans{grid-template-columns:1fr}
  .plan{border-right:0;border-bottom:1px solid var(--line)}
  .plan:last-child{border-bottom:0}
  section{padding:76px 0}
  .hero{padding:76px 0 64px}
  .marquee{margin-top:56px}
}
@media(max-width:600px){
  .wrap{padding:0 20px}
  .nums{grid-template-columns:1fr 1fr}
  .made{grid-template-columns:1fr}
  .ask{padding:14px 14px 14px 16px}
  .ask .txt{font-size:14.5px}
}