/* ===== YuChat 二级页面共享样式(联系 / 隐私 / 条款) ===== */
:root{
  --bg: oklch(1 0 0);
  --surface: oklch(0.972 0.008 252);
  --ink: oklch(0.23 0.02 258);
  --muted: oklch(0.44 0.03 258);
  --faint: oklch(0.53 0.025 258);
  --line: oklch(0.905 0.014 252);
  --primary: oklch(0.53 0.195 258);
  --primary-deep: oklch(0.43 0.16 259);
  --primary-tint: oklch(0.94 0.035 252);
  --pine: oklch(0.245 0.05 259);
  --pine-2: oklch(0.30 0.055 259);
  --pine-ink: oklch(0.94 0.015 252);
  --pine-muted: oklch(0.76 0.04 255);
  --radius: 14px;
  --font-cjk: "PingFang SC","HarmonyOS Sans SC","MiSans","Hiragino Sans GB","Source Han Sans SC","Microsoft YaHei",sans-serif;
  --font-num: "Archivo", var(--font-cjk);
  --z-nav: 50;
}
*{margin:0;padding:0;box-sizing:border-box}
html{scroll-behavior:smooth}
@media (prefers-reduced-motion: reduce){ html{scroll-behavior:auto} }
body{font-family:var(--font-cjk);color:var(--ink);background:var(--bg);line-height:1.75;font-size:16px;-webkit-font-smoothing:antialiased;overflow-x:hidden}
img,svg{max-width:100%;display:block}
a{color:inherit;text-decoration:none}
ul{list-style:none}
h1,h2,h3{text-wrap:balance;line-height:1.3}
.wrap{max-width:1160px;margin:0 auto;padding:0 clamp(20px, 4vw, 40px)}
.num{font-family:var(--font-num);font-variant-numeric:tabular-nums}

.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;padding:13px 28px;border-radius:999px;font-size:16px;font-weight:600;transition:background .18s cubic-bezier(.22,1,.36,1), transform .18s cubic-bezier(.22,1,.36,1), box-shadow .18s;cursor:pointer;border:none;white-space:nowrap}
.btn-primary{background:var(--primary);color:#fff}
.btn-primary:hover{background:var(--primary-deep);transform:translateY(-1px)}
.btn-ghost{background:transparent;color:var(--ink);box-shadow:inset 0 0 0 1.5px var(--line)}
.btn-ghost:hover{box-shadow:inset 0 0 0 1.5px var(--primary);color:var(--primary-deep)}
.btn-light{background:#fff;color:var(--pine)}
.btn-light:hover{background:var(--pine-ink);transform:translateY(-1px)}
.btn .arr{transition:transform .18s cubic-bezier(.22,1,.36,1)}
.btn:hover .arr{transform:translateX(3px)}

/* header */
.site-head{position:fixed;inset:0 0 auto 0;z-index:var(--z-nav);background:var(--bg);border-bottom:1px solid transparent;transition:border-color .25s, box-shadow .25s}
.site-head.scrolled{border-bottom-color:var(--line);box-shadow:0 1px 0 oklch(0 0 0 / .02)}
.head-in{display:flex;align-items:center;gap:36px;height:68px}
.logo{display:flex;align-items:center;gap:10px;font-size:20px;font-weight:800;letter-spacing:.02em}
.logo .dot{width:12px;height:12px;border-radius:50%;background:var(--primary);position:relative;flex:none}
.logo .dot::after{content:"";position:absolute;inset:-4px;border-radius:50%;border:2px solid var(--primary);opacity:.35;animation:pulse 2.4s cubic-bezier(.22,1,.36,1) infinite}
@keyframes pulse{0%{transform:scale(.6);opacity:.5}70%{transform:scale(1.25);opacity:0}100%{transform:scale(1.25);opacity:0}}
.logo .brand{font-family:var(--font-num);font-weight:800;letter-spacing:-0.01em}
.logo .en{font-size:10.5px;font-weight:500;color:var(--faint);letter-spacing:.2em;display:block;line-height:1;margin-top:2px}
.main-nav{display:flex;gap:6px;margin-left:8px}
.main-nav a{padding:8px 14px;border-radius:999px;font-size:15px;color:var(--muted);font-weight:500;transition:color .15s, background .15s}
.main-nav a:hover{color:var(--ink);background:var(--surface)}
.main-nav a.on{color:var(--primary-deep);font-weight:600}
.head-cta{margin-left:auto;display:flex;align-items:center;gap:18px}
.head-cta .lang{font-family:var(--font-num);font-size:13px;font-weight:600;color:var(--faint)}
.head-cta .lang b{color:var(--ink)}
.head-cta .btn{padding:9px 22px;font-size:15px}
.menu-btn{display:none;background:none;border:none;cursor:pointer;padding:8px}
.menu-btn span{display:block;width:22px;height:2px;background:var(--ink);margin:5px 0;border-radius:2px;transition:transform .2s, opacity .2s}
.menu-btn[aria-expanded="true"] span:nth-child(1){transform:translateY(7px) rotate(45deg)}
.menu-btn[aria-expanded="true"] span:nth-child(2){opacity:0}
.menu-btn[aria-expanded="true"] span:nth-child(3){transform:translateY(-7px) rotate(-45deg)}
.mobile-nav{display:none}

/* footer */
.site-foot{background:var(--pine);color:var(--pine-muted);border-top:1px solid oklch(1 0 0 / .12)}
.foot-in{display:grid;grid-template-columns:minmax(0,2fr) repeat(3,minmax(0,1fr));gap:36px;padding:clamp(44px,6vw,64px) 0 40px}
.foot-brand .logo{color:#fff;margin-bottom:14px}
.foot-brand p{font-size:13.5px;line-height:1.8;max-width:26em}
.site-foot h4{color:#fff;font-size:14px;font-weight:700;margin-bottom:16px}
.site-foot li{margin-bottom:10px}
.site-foot li a{font-size:13.5px;color:var(--pine-muted);transition:color .15s}
.site-foot li a:hover{color:#fff}
.foot-base{border-top:1px solid oklch(1 0 0 / .12);padding:20px 0;display:flex;justify-content:space-between;gap:16px;flex-wrap:wrap;font-size:12.5px}
.foot-base a:hover{color:#fff}
.foot-base .pol{display:flex;gap:20px}

/* page hero */
.page-hero{padding:clamp(116px,15vh,150px) 0 clamp(18px,3vw,30px)}
.page-hero .crumb{font-size:13px;color:var(--faint);margin-bottom:14px}
.page-hero .crumb a:hover{color:var(--primary-deep)}
.page-hero h1{font-size:clamp(1.9rem,4.4vw,2.9rem);font-weight:800;letter-spacing:-0.012em;margin-bottom:12px}
.page-hero .lead{font-size:16.5px;color:var(--muted);max-width:44em}
.page-hero .updated{font-size:13px;color:var(--faint);margin-top:14px}
.page-hero .updated b{color:var(--ink);font-weight:600}

/* legal layout (privacy / terms) */
.legal{padding:clamp(16px,2.5vw,28px) 0 clamp(60px,8vw,96px)}
.legal-grid{display:grid;grid-template-columns:minmax(0,240px) minmax(0,1fr);gap:clamp(28px,4vw,64px);align-items:start}
.toc{position:sticky;top:96px;font-size:13.5px}
.toc .toc-h{font-size:12px;font-weight:700;letter-spacing:.06em;color:var(--faint);margin-bottom:12px}
.toc ol{list-style:none;counter-reset:toc;display:flex;flex-direction:column;gap:2px}
.toc li{counter-increment:toc}
.toc a{display:block;padding:6px 10px;border-radius:8px;color:var(--muted);border-left:2px solid transparent;transition:color .15s, background .15s}
.toc a::before{content:counter(toc, decimal-leading-zero) "  ";font-family:var(--font-num);font-size:11px;color:var(--faint)}
.toc a:hover{color:var(--ink);background:var(--surface)}
.toc a.active{color:var(--primary-deep);background:var(--primary-tint);font-weight:600}
.legal-body{max-width:74ch;font-size:15.5px;color:var(--ink)}
.legal-body .intro{font-size:16.5px;color:var(--muted);padding:20px 22px;background:var(--surface);border:1px solid var(--line);border-radius:12px;margin-bottom:36px}
.legal-body section{scroll-margin-top:92px;margin-bottom:38px}
.legal-body h2{font-size:20px;font-weight:800;letter-spacing:-0.01em;margin-bottom:14px;display:flex;gap:12px;align-items:baseline}
.legal-body h2 .n{font-family:var(--font-num);font-size:14px;font-weight:700;color:var(--primary-deep);flex:none}
.legal-body h3{font-size:16px;font-weight:700;margin:20px 0 8px}
.legal-body p{color:var(--muted);margin-bottom:12px}
.legal-body p b,.legal-body li b{color:var(--ink);font-weight:600}
.legal-body a{color:var(--primary-deep);font-weight:600}
.legal-body a:hover{text-decoration:underline}
.legal-body ul.dl{display:flex;flex-direction:column;gap:9px;margin:6px 0 14px}
.legal-body ul.dl li{position:relative;padding-left:20px;color:var(--muted)}
.legal-body ul.dl li::before{content:"";position:absolute;left:2px;top:11px;width:6px;height:6px;border-radius:50%;background:var(--primary)}
.legal-body .callout{display:flex;gap:11px;padding:14px 16px;background:var(--primary-tint);border-radius:10px;margin:14px 0;font-size:14.5px;color:var(--pine)}
.legal-body .callout svg{flex:none;color:var(--primary-deep);margin-top:2px}
.legal-body .rights{display:grid;grid-template-columns:repeat(auto-fit,minmax(200px,1fr));gap:10px;margin:8px 0 14px}
.legal-body .rights .r{border:1px solid var(--line);border-radius:10px;padding:13px 15px}
.legal-body .rights .r b{display:block;font-size:14.5px;margin-bottom:3px}
.legal-body .rights .r span{font-size:13px;color:var(--muted)}
.legal-body .lastblock{margin-top:30px;padding-top:22px;border-top:1px solid var(--line);font-size:14px;color:var(--faint)}
@media (max-width: 860px){
  .legal-grid{grid-template-columns:1fr}
  .toc{display:none}
}

@media (prefers-reduced-motion: reduce){ .logo .dot::after{animation:none} }
@media (max-width: 760px){
  .main-nav,.head-cta .lang{display:none}
  .menu-btn{display:block;margin-left:auto}
  .head-cta{margin-left:0}
  .head-in{justify-content:space-between}
  .mobile-nav{display:none;position:fixed;inset:68px 0 auto 0;z-index:var(--z-nav);background:var(--bg);border-bottom:1px solid var(--line);padding:10px 20px 22px;flex-direction:column}
  .mobile-nav.open{display:flex}
  .mobile-nav a{padding:13px 6px;border-bottom:1px solid var(--line);font-size:16px;font-weight:500}
  .mobile-nav a:last-child{border-bottom:none}
  .foot-in{grid-template-columns:1fr;gap:28px}
}