:root{
  --desk:#e8e4da;
  --ink:#2b2a28;
  --mute:#6f6c66;
  --win:#fbfaf7;
  --line:#d9d4c8;
  --blue:#3d6ea8;
  --ok:#2f7d4a;
}
*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth}
body{
  font-family:"Segoe UI","PingFang SC","Noto Sans SC",sans-serif;
  background:linear-gradient(180deg,#f3efe6 0%,var(--desk) 28%,#efebe3 100%);
  color:var(--ink);
  line-height:1.55;
}
a{color:inherit;text-decoration:none}
img{max-width:100%;height:auto;display:block}
nav{
  position:sticky;top:0;z-index:10;
  display:flex;align-items:center;justify-content:space-between;
  padding:12px 6vw;background:rgba(251,250,247,.92);
  border-bottom:1px solid var(--line);
}
.logo{font-weight:700}
.menu{display:flex;gap:20px;font-size:14px;color:var(--mute)}
.menu a:hover{color:var(--ink)}
.btn{
  display:inline-flex;align-items:center;justify-content:center;
  min-height:36px;padding:0 14px;border-radius:6px;
  background:var(--blue);color:#fff;font-size:13px;font-weight:600;
}
.btn:hover{filter:brightness(1.06)}
.hero{padding:48px 6vw 40px}
.hero.compact{padding:48px 6vw 24px}
.when{font-size:clamp(24px,3.4vw,38px);font-weight:700;margin-bottom:12px}
h1{font-size:clamp(20px,2.6vw,28px);font-weight:700;max-width:18ch}
.sub{margin-top:8px;color:var(--mute);max-width:44ch}
.line{margin:12px 0 22px}
.desk{
  display:grid;grid-template-columns:1.1fr .9fr .9fr;gap:12px;
  margin-top:28px;transform:perspective(1200px) rotateX(6deg);
  transform-origin:top center;
}
.win{
  background:var(--win);border:1px solid #cfc9bb;border-radius:8px;
  box-shadow:0 10px 24px rgba(43,42,40,.08);
  overflow:hidden;min-height:220px;
}
.win header{
  padding:8px 10px;font-size:12px;background:#f0ece3;
  border-bottom:1px solid var(--line);color:var(--mute);
}
.shop img{height:120px;object-fit:cover;width:100%;filter:grayscale(.2)}
.shop p,.panel p{padding:10px 12px;font-size:13px}
.chat{padding-bottom:12px}
.bubble{margin:10px 12px;padding:8px 10px;border-radius:8px;font-size:13px;max-width:86%}
.bubble.in{background:#efeae0}
.bubble.out{background:#d7e4f4;margin-left:auto}
.panel .ok{color:var(--ok);font-weight:600}
section{padding:56px 6vw}
section>p{margin:8px 0 24px;color:var(--mute);max-width:56ch}
.cards{display:grid;grid-template-columns:repeat(3,1fr);gap:12px}
.cards article{background:var(--win);border:1px solid var(--line);border-radius:8px;padding:16px}
.cards h3{font-size:15px;margin-bottom:8px}
.cards p{color:var(--mute);font-size:14px}
.cards b{display:block;margin-top:12px}
.cards small{color:var(--mute)}
.three{grid-template-columns:repeat(3,1fr)}
.split{display:grid;grid-template-columns:1fr 1fr;gap:32px;align-items:center}
.split img,.docs img{width:100%;height:280px;object-fit:cover;border-radius:8px;border:1px solid var(--line);filter:grayscale(.15)}
.split ul{list-style:none;display:grid;grid-template-columns:1fr 1fr;gap:8px;margin:16px 0 20px}
.split li{background:var(--win);border:1px solid var(--line);padding:8px 10px;border-radius:6px;font-size:14px}
details{border-bottom:1px solid var(--line);padding:12px 0}
summary{cursor:pointer;font-weight:600}
details p{margin-top:8px;max-width:70ch;color:var(--mute)}
.ghost{display:inline-block;margin-top:12px;color:var(--blue);font-size:13px}
.help{display:grid;grid-template-columns:200px 1fr;gap:28px}
.help aside{display:flex;flex-direction:column;gap:8px;position:sticky;top:64px;align-self:start}
.help aside a{color:var(--mute);font-size:14px}
.help aside a:hover{color:var(--blue)}
.docs article{margin-bottom:32px}
.docs img{max-width:460px;height:210px;margin:14px 0}
.policy{margin-top:12px;padding:14px;background:var(--win);border:1px solid var(--line);border-radius:8px}
footer{padding:36px 6vw 20px;border-top:1px solid var(--line);background:#f7f4ee}
.cols{display:grid;grid-template-columns:2fr 1fr 1fr 1fr;gap:18px}
.cols h4{font-size:13px;margin-bottom:8px}
.cols a,.cols p{display:block;margin:6px 0;color:var(--mute);font-size:13px}
.copy{margin-top:18px;font-size:12px;color:var(--mute)}
@media (max-width:980px){
  .menu{display:none}
  .desk,.cards,.three,.split,.help,.cols{grid-template-columns:1fr}
  .desk{transform:none}
}

@media (prefers-reduced-motion:reduce){html{scroll-behavior:auto}*,*::before,*::after{animation:none!important;transition:none!important}}