:root{
  --paper:#F4F7FB;--card:#FFFFFF;--ink:#0B1B33;--mute:rgba(11,27,51,.64);--line:rgba(11,27,51,.11);
  --navy:#0E2854;--deep:#06162C;--court:#1C4A8C;--lime:#C6EE2C;--accent:#3F7A00;--sky:#2F6FD6;
  --red:#E5383B;--amber:#E8820C;
  --f:-apple-system,BlinkMacSystemFont,"PingFang SC","Hiragino Sans GB","Microsoft YaHei","Helvetica Neue",Arial,sans-serif;
}
@media (prefers-color-scheme:dark){:root{
  --paper:#07152B;--card:#0E2349;--ink:#F2F6FC;--mute:rgba(242,246,252,.66);--line:rgba(255,255,255,.11);--accent:#CCED33;
}}
*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth}
body{margin:0;background:var(--paper);color:var(--ink);font:16px/1.75 var(--f);font-variant-numeric:tabular-nums;-webkit-font-smoothing:antialiased}
a{color:var(--accent);text-underline-offset:3px}
img,svg{max-width:100%;display:block}
:focus-visible{outline:3px solid var(--lime);outline-offset:3px;border-radius:6px}

/* language switch: only blocks that carry data-l are toggled */
[data-l]{display:none}
html[lang=zh] [data-l=zh],html[lang=en] [data-l=en]{display:revert}

.wrap{max-width:1120px;margin:0 auto;padding:0 24px}

/* ---------- top bar ---------- */
.top{display:flex;align-items:center;justify-content:space-between;gap:16px;padding-block:20px}
.brand{display:flex;align-items:center;gap:10px;color:inherit;text-decoration:none;font-weight:700;letter-spacing:.01em}
.brand img{width:32px;height:32px;border-radius:8px}
.top nav{display:flex;align-items:center;gap:22px;font-size:15px}
.top nav a{color:inherit;text-decoration:none;opacity:.82}
.top nav a:hover{opacity:1;text-decoration:underline}
.lang{display:flex;border:1px solid currentColor;border-radius:999px;overflow:hidden;opacity:.9}
.lang button{all:unset;cursor:pointer;padding:3px 12px;font-size:13px;line-height:1.6}
.lang button.on{background:var(--lime);color:var(--deep);font-weight:700}
.on-dark{color:#fff}
.on-paper .lang{border-color:var(--line)}
@media (max-width:720px){.top nav .nl{display:none}}

/* ---------- hero ---------- */
.hero{background:radial-gradient(900px 520px at 85% 10%,rgba(198,238,44,.14),transparent 60%),linear-gradient(180deg,#0E2854,#06162C);color:#fff;overflow:hidden}
.hero-grid{display:grid;grid-template-columns:1.05fr .95fr;gap:40px;align-items:center;padding-block:36px 72px}
.hero h1{font-size:clamp(38px,5.6vw,68px);line-height:1.12;letter-spacing:-.01em;margin:0 0 20px;font-weight:800}
.hero p.lead{font-size:18px;line-height:1.8;color:rgba(255,255,255,.8);max-width:30em;margin:0 0 28px}
.chip{display:inline-flex;align-items:center;gap:8px;font-size:14px;color:rgba(255,255,255,.82);border:1px solid rgba(255,255,255,.22);border-radius:999px;padding:6px 14px}
.chip i{width:8px;height:8px;border-radius:50%;background:var(--lime);display:block}
.hero .links{display:flex;gap:12px;flex-wrap:wrap;margin-top:24px}
.btn{display:inline-block;padding:11px 22px;border-radius:12px;font-weight:700;text-decoration:none;font-size:15px}
.btn.lime{background:var(--lime);color:var(--deep)}
.btn.ghost{border:1px solid rgba(255,255,255,.32);color:#fff}
.btn.lime:hover{filter:brightness(1.06)}.btn.ghost:hover{background:rgba(255,255,255,.08)}

.court-wrap{position:relative;max-width:360px;margin-left:auto}
.court-wrap svg{width:100%;height:auto;filter:drop-shadow(0 30px 50px rgba(0,0,0,.45))}
.readout{position:absolute;left:41%;top:30%;background:var(--lime);color:var(--deep);border-radius:12px;padding:8px 14px;line-height:1.2;opacity:0;transform:translateY(6px);animation:pop .5s 2.2s cubic-bezier(.2,.8,.2,1) forwards}
.readout b{font-size:28px;font-weight:800;display:block;letter-spacing:-.01em}
.readout small{font-size:12px;font-weight:600;opacity:.75}
.readout::before{content:"";position:absolute;left:-7px;top:18px;border:7px solid transparent;border-right-color:var(--lime);border-left:0}
@keyframes pop{to{opacity:1;transform:none}}
.trace{stroke-dasharray:1;stroke-dashoffset:1;animation:draw 1.6s .5s cubic-bezier(.2,.6,.4,1) forwards}
@keyframes draw{to{stroke-dashoffset:0}}
.ripple{transform-box:fill-box;transform-origin:center;opacity:0;animation:rip 1.2s 2.1s ease-out forwards}
@keyframes rip{0%{opacity:.9;transform:scale(.3)}100%{opacity:0;transform:scale(2.6)}}
.landed{opacity:0;animation:fade .3s 2.1s forwards}
@keyframes fade{to{opacity:1}}
@media (prefers-reduced-motion:reduce){
  .trace{animation:none;stroke-dashoffset:0}.ripple{animation:none;opacity:0}.landed{animation:none;opacity:1}.readout{animation:none;opacity:1;transform:none}
  html{scroll-behavior:auto}
}
@media (max-width:860px){
  .hero-grid{grid-template-columns:1fr;gap:28px;padding-bottom:56px}
  .court-wrap{margin:0 auto;max-width:300px}
}

/* ---------- sections ---------- */
section{padding:88px 0}
section.tight{padding:64px 0}
h2{font-size:clamp(28px,3.6vw,40px);line-height:1.25;margin:0 0 14px;letter-spacing:-.005em;font-weight:800}
h3{font-size:20px;margin:0 0 8px;font-weight:700}
.kicker{color:var(--mute);max-width:36em;margin:0 0 8px;font-size:17px}
.sec-head{margin-bottom:48px}

.feat{display:grid;grid-template-columns:1fr 1fr;gap:56px;align-items:center;padding:36px 0}
.feat+.feat{border-top:1px solid var(--line)}
.feat.flip .txt{order:2}
.feat .txt p{color:var(--mute);margin:0 0 12px;max-width:30em}
.feat .note{font-size:14px;color:var(--mute);border-left:3px solid var(--lime);padding-left:12px;margin-top:16px}
.screen{background:linear-gradient(180deg,#13284A,#0B1D3A);border-radius:26px;padding:26px;color:#fff;box-shadow:0 24px 50px -24px rgba(6,22,44,.5);border:1px solid rgba(255,255,255,.08)}
.screen .cap{font-size:13px;color:rgba(255,255,255,.58);margin-top:14px;text-align:center}
@media (max-width:860px){
  .feat{grid-template-columns:1fr;gap:28px}.feat.flip .txt{order:0}
  section{padding:64px 0}
}

.band{background:var(--navy);color:#fff}
.band .kicker,.band p{color:rgba(255,255,255,.72)}
.band h2,.band h3{color:#fff}

/* steps */
.steps{list-style:none;margin:0;padding:0;display:grid;grid-template-columns:repeat(4,1fr);gap:0;counter-reset:s}
.steps li{padding:0 24px 0 0;position:relative;counter-increment:s}
.steps li::before{content:counter(s);display:grid;place-items:center;width:38px;height:38px;border-radius:50%;background:var(--lime);color:var(--deep);font-weight:800;margin-bottom:16px;position:relative;z-index:1}
.steps li::after{content:"";position:absolute;left:44px;right:8px;top:19px;height:2px;background:rgba(255,255,255,.2)}
.steps li:last-child::after{display:none}
.steps p{font-size:15px;margin:0}
@media (max-width:860px){
  .steps{grid-template-columns:1fr;gap:28px}
  .steps li{padding:0 0 0 56px}.steps li::before{position:absolute;left:0;top:0;margin:0}
  .steps li::after{left:18px;top:42px;bottom:-24px;right:auto;width:2px;height:auto}
}

/* privacy trio */
.trio{display:grid;grid-template-columns:repeat(3,1fr);gap:0;border-top:1px solid var(--line);border-bottom:1px solid var(--line)}
.trio>div{padding:28px 28px 28px 0}
.trio>div+div{padding-left:28px;border-left:1px solid var(--line)}
.trio p{margin:0;color:var(--mute);font-size:15px}
@media (max-width:860px){.trio{grid-template-columns:1fr}.trio>div,.trio>div+div{padding:22px 0;border-left:0}.trio>div+div{border-top:1px solid var(--line)}}

/* about */
.about{display:grid;grid-template-columns:.8fr 1.2fr;gap:56px;align-items:start}
.about .me{display:flex;align-items:center;gap:16px}
.about .me img{width:72px;height:72px;border-radius:18px}
.about p{color:var(--mute);margin:0 0 14px;max-width:34em}
@media (max-width:860px){.about{grid-template-columns:1fr;gap:24px}}

/* faq */
details{border-top:1px solid var(--line);padding:18px 0}
details:last-of-type{border-bottom:1px solid var(--line)}
summary{cursor:pointer;font-weight:700;font-size:17px;list-style:none;display:flex;justify-content:space-between;gap:16px}
summary::-webkit-details-marker{display:none}
summary::after{content:"+";font-weight:400;font-size:22px;line-height:1;color:var(--mute)}
details[open] summary::after{content:"–"}
details p{margin:10px 0 0;color:var(--mute);max-width:40em}

/* footer */
footer{background:var(--deep);color:rgba(255,255,255,.72);padding:40px 0 48px;font-size:14px}
footer .row{display:flex;flex-wrap:wrap;gap:12px 28px;justify-content:space-between;align-items:center}
footer a{color:#fff}
footer .links{display:flex;gap:22px;flex-wrap:wrap}
footer .icp{margin-top:16px;font-size:13px;opacity:.7}

/* home: app card */
.appcard{display:grid;grid-template-columns:120px 1fr;gap:28px;align-items:center;background:var(--card);border:1px solid var(--line);border-radius:24px;padding:28px;box-shadow:0 20px 40px -28px rgba(6,22,44,.35)}
.appcard img{width:120px;height:120px;border-radius:28px}
.appcard h3{font-size:26px;margin:0 0 6px}
.appcard p{margin:0 0 14px;color:var(--mute)}
.appcard .links{display:flex;gap:18px;flex-wrap:wrap}
@media (max-width:640px){.appcard{grid-template-columns:1fr}.appcard img{width:88px;height:88px;border-radius:20px}}

/* document pages */
.doc{max-width:720px;margin:0 auto;padding:12px 24px 80px}
.doc h1{font-size:clamp(30px,5vw,42px);line-height:1.2;margin:24px 0 6px;font-weight:800}
.doc .sub{color:var(--mute);margin:0 0 28px;font-size:15px}
.doc h2{font-size:21px;margin:36px 0 8px}
.doc h3{font-size:17px;margin:22px 0 4px}
.doc p,.doc li{color:var(--ink)}
.doc ul{padding-left:1.3em}.doc li{margin:6px 0}
.callout{background:var(--card);border:1px solid var(--line);border-left:4px solid var(--lime);border-radius:12px;padding:16px 18px;margin:18px 0}

.faq{max-width:820px}