:root{
  color-scheme:light;
  --bg:#F6F5F4;
  --bg-top:#FBFAF9;
  --bg-bottom:#EFEDEB;
  --panel:#FFFFFF;
  --panel-2:#EDEBE9;
  --border:#E0DCDA;
  --border-strong:#CBC4C1;
  --accent:#B4233C;
  --accent-dark:#861A2D;
  --coral:#E0614F;
  --text:#1B1718;
  --muted:#6A6264;
  --success:#1F8A5B;
  --warn:#B7791F;
  --error:#C9302C;
  --ink:#1B1718;
  --on-ink:#FFFFFF;
  --on-accent:#FFFFFF;
  --on-accent-soft:rgb(255 255 255 / .8);
  --on-accent-chip:rgb(255 255 255 / .18);
  --board-top:#F4F2F0;
  --board-bottom:#E8E4E1;
  --board-edge:rgb(27 23 24 / .08);
  --glass:rgb(255 255 255 / .82);
  --glass-nav:rgb(255 255 255 / .74);
  --glass-soft:rgb(255 255 255 / .62);
  --menubar:rgb(255 255 255 / .55);
  --foot-tint:rgb(246 245 244 / .72);
  --hi:rgb(255 255 255 / .95);
  --line:rgb(27 23 24 / .07);
  --win-edge:rgb(27 23 24 / .09);
  --sheen:rgb(255 255 255 / .34);
  --clear:rgb(255 255 255 / 0);
  --light-ring:rgb(27 23 24 / .14);
  --accent-06:rgb(180 35 60 / .06);
  --accent-10:rgb(180 35 60 / .10);
  --accent-12:rgb(180 35 60 / .12);
  --accent-14:rgb(180 35 60 / .14);
  --accent-20:rgb(180 35 60 / .20);
  --accent-30:rgb(180 35 60 / .30);
  --accent-34:rgb(180 35 60 / .34);
  --accent-50:rgb(180 35 60 / .50);
  --coral-20:rgb(224 97 79 / .20);
  --coral-0:rgb(224 97 79 / 0);
  --shadow-neutral:rgb(27 23 24 / .10);
  --shadow-ink:rgb(27 23 24 / .35);
  --flag-shadow:rgb(27 23 24 / .25);
  --flag-red:#C8102E;
  --flag-navy:#012169;
  --flag-white:#FFFFFF;
  --flag-edge:rgb(27 23 24 / .16);
  --r-key:6px;
  --r-s:8px;
  --r-m:10px;
  --r-l:12px;
  --r-pill:999px;
  --r-round:50%;
  --font-display:"Inter","Noto Sans SC","PingFang SC","Hiragino Sans","Microsoft YaHei",system-ui,sans-serif;
  --font-body:"Inter","Noto Sans SC","PingFang SC","Hiragino Sans GB","Microsoft YaHei",system-ui,sans-serif;
  --font-mono:"JetBrains Mono",ui-monospace,"SFMono-Regular",Menlo,Consolas,monospace;
  --gutter:24px;
  --content-width:1248px;
  --reading-width:800px;
  --header-height:76px;
  --anchor-offset:92px;
  --toc-offset:148px;
  --space-section:80px;
  --shadow-panel:inset 0 1px 0 var(--hi),0 24px 60px -28px var(--accent-12);
  --ease-out:cubic-bezier(.2,.7,.2,1);
}
*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
html{-webkit-text-size-adjust:100%;scroll-padding-top:var(--anchor-offset);scroll-behavior:smooth}
body{font-family:var(--font-body);color:var(--text);background:var(--bg);line-height:1.65;-webkit-font-smoothing:antialiased}
a{color:inherit;text-decoration:none}
button,input,select,textarea{font:inherit;color:inherit}
button{background:none;border:0;cursor:pointer}
button:disabled{cursor:not-allowed}
img,video{display:block;max-width:100%;height:auto}
svg{display:block;flex-shrink:0}
ul,ol{list-style:none}
fieldset{border:0}
[hidden]{display:none!important}
:where(a,button,input,select,textarea,summary,[tabindex]):focus-visible{outline:2px solid var(--accent);outline-offset:3px}
::selection{background:var(--accent-20);color:var(--text)}
h1,h2,h3{font-family:var(--font-display);font-weight:800;line-height:1.2;letter-spacing:-.02em;text-wrap:balance;overflow-wrap:break-word}
h1{font-size:clamp(52px,5vw,66px)}
h2{font-size:clamp(28px,3vw,40px)}
h3{font-size:22px;font-weight:700}
p{overflow-wrap:break-word}
small{font-size:.85em}
strong{font-weight:600}
code,kbd,pre,.mono{font-family:var(--font-mono)}
code{overflow-wrap:anywhere}
pre{max-width:100%;overflow-x:auto;padding:20px;border:1px solid var(--border);border-radius:var(--r-s);background:var(--panel-2);font-size:13px}
pre code{overflow-wrap:normal;white-space:pre}
.wrap{width:100%;max-width:var(--content-width);padding-inline:var(--gutter);margin-inline:auto}
.reading-wrap{width:100%;max-width:var(--reading-width);padding-inline:var(--gutter);margin-inline:auto}
.sec{padding-top:var(--space-section);padding-bottom:var(--space-section)}
.section-head{margin-bottom:32px;max-width:800px}
.section-head p{margin-top:16px;color:var(--muted)}
.stack>*+*{margin-top:20px}
.grid{display:grid;gap:24px}
.grid>*{min-width:0}
.grid-2{grid-template-columns:repeat(2,minmax(0,1fr))}
.grid-3{grid-template-columns:repeat(3,minmax(0,1fr))}
.grid-5{grid-template-columns:repeat(5,minmax(0,1fr))}
.no-break{white-space:nowrap}
.muted{color:var(--muted)}
.accent{color:var(--accent)}
.kicker{font-family:var(--font-mono);font-size:12px;color:var(--muted);letter-spacing:.04em;margin-bottom:12px}
.icon{width:20px;height:20px;flex-shrink:0}
.ico-s{fill:none;stroke:currentColor;stroke-width:1.7;stroke-linecap:round;stroke-linejoin:round}
.sprite{position:absolute;width:0;height:0;overflow:hidden}
.panel,.card{min-width:0;background:var(--panel);border:1px solid var(--border);border-radius:var(--r-l);box-shadow:var(--shadow-panel)}
.card{padding:24px}
.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;min-height:44px;padding:10px 18px 10px 14px;border-radius:var(--r-m);font-size:15px;font-weight:600;line-height:1.5;white-space:nowrap;flex-shrink:0;transition:transform .2s var(--ease-out),box-shadow .2s var(--ease-out)}
.btn svg{width:18px;height:18px}
.btn-main,.btn-primary{color:var(--on-accent);background:linear-gradient(135deg,var(--accent),var(--coral));box-shadow:inset 0 1px 0 var(--sheen),inset 0 0 0 1px var(--accent-dark),0 12px 26px -12px var(--accent-50)}
.btn-ghost,.btn-secondary{color:var(--text);background:var(--panel);box-shadow:inset 0 1px 0 var(--hi),0 0 0 1px var(--border),0 8px 18px -12px var(--shadow-neutral)}
.btn:hover:not(:disabled){transform:translateY(-1px)}
.btn:active:not(:disabled){transform:translateY(0)}
.btn:disabled,.btn[aria-disabled="true"]{background:var(--panel-2);color:var(--muted);box-shadow:inset 0 0 0 1px var(--border);pointer-events:none}
.btn-text{display:inline-flex;align-items:center;min-height:32px;color:var(--accent-dark);font-weight:600}
.btn-text:hover{text-decoration:underline}
.badge,.tag{display:inline-flex;align-items:center;gap:6px;max-width:100%;padding:3px 8px;border-radius:var(--r-key);background:var(--panel-2);color:var(--muted);font-size:12px;overflow-wrap:anywhere}
.badge-accent{background:var(--accent-10);color:var(--accent-dark)}
.badge-success{color:var(--success)}
.badge-warn{color:var(--warn)}
.badge-error{color:var(--error)}
.status-dot{display:inline-block;flex-shrink:0;width:6px;height:6px;border-radius:var(--r-round);background:currentColor}
.kbd{display:inline-flex;align-items:center;justify-content:center;min-width:20px;height:20px;padding:0 5px;border-radius:var(--r-key);background:var(--panel);box-shadow:inset 0 -1px 0 var(--border),0 0 0 1px var(--border);font-family:var(--font-mono);font-size:11px;line-height:1;color:var(--text)}
.kbd-lg{min-width:26px;height:26px;font-size:13px}
.topbar{position:relative;z-index:80;padding-top:12px}
.navbox{position:relative;display:flex;align-items:center;flex-wrap:nowrap;gap:16px;height:52px;padding:0 8px 0 14px;background:var(--glass-nav);border:1px solid var(--border);border-radius:var(--r-l);box-shadow:inset 0 1px 0 var(--hi),0 10px 28px -16px var(--shadow-neutral);backdrop-filter:blur(14px) saturate(1.2)}
.brand{display:inline-flex;align-items:center;gap:10px;flex-shrink:0;min-height:32px;font-family:var(--font-display);font-weight:800;font-size:17px;letter-spacing:-.01em;line-height:1.5}
.brand-mark{width:28px;height:28px}
.brand-zh{color:var(--muted);font-weight:500}
.desktop-nav{flex:1;min-width:0}
.navlinks{display:flex;align-items:center;justify-content:center;gap:2px;list-style:none;margin:0;padding:0}
.navlinks li{min-width:0}
.navlinks a{display:flex;align-items:center;justify-content:center;min-height:32px;padding:6px 12px;border-radius:var(--r-pill);font-size:14px;color:var(--muted);white-space:nowrap;line-height:1.5;transition:color .2s,background-color .2s}
.navlinks a:hover{color:var(--text)}
.navlinks a[aria-current="page"]{background:var(--panel-2);color:var(--text);font-weight:600;box-shadow:inset 0 0 0 1px var(--border)}
.nav-end{display:flex;align-items:center;gap:4px;flex-shrink:0;margin-left:auto}
.language{position:relative}
.lang{display:inline-flex;align-items:center;justify-content:center;gap:6px;width:auto;min-width:44px;min-height:34px;padding:0 12px;border-radius:var(--r-pill);font-size:13px;color:var(--muted);white-space:nowrap}
.lang span{white-space:nowrap}
.lang:hover{color:var(--text)}
.lang svg{width:15px;height:15px}
.lang-panel{position:absolute;right:0;top:calc(100% + 10px);z-index:100;min-width:180px;padding:6px;border:1px solid var(--border);border-radius:var(--r-m);background:var(--panel);box-shadow:var(--shadow-panel)}
.lang-panel a{display:flex;align-items:center;min-height:44px;padding:8px 12px;border-radius:var(--r-s);font-size:14px}
.lang-panel a:hover,.lang-panel a[aria-current="true"]{background:var(--accent-10);color:var(--accent-dark)}
.login{display:inline-flex;align-items:center;justify-content:center;min-height:36px;padding:0 18px;border-radius:var(--r-pill);background:var(--ink);color:var(--on-ink);font-size:14px;font-weight:600;white-space:nowrap;box-shadow:inset 0 1px 0 var(--on-accent-chip),0 8px 16px -8px var(--shadow-ink)}
.nav-toggle{display:none;align-items:center;justify-content:center;flex-direction:column;gap:4px;min-width:44px;min-height:44px;border-radius:var(--r-s)}
.nav-toggle-line{display:block;width:20px;height:2px;background:currentColor}
.nav-drawer{display:none;position:fixed;top:var(--header-height);inset-inline:0;z-index:75;height:calc(100dvh - var(--header-height));max-height:calc(100dvh - var(--header-height));padding:16px var(--gutter) 32px;background:var(--panel);overflow-y:auto;overscroll-behavior:contain}
.nav-drawer a{display:flex;align-items:center;width:100%;min-height:44px;padding:12px 16px;border-radius:var(--r-s)}
.nav-drawer a[aria-current]{color:var(--accent-dark);background:var(--accent-10)}
.drawer-languages{border-top:1px solid var(--border);margin-top:16px;padding-top:16px}
.nav-veil{position:fixed;inset:var(--header-height) 0 0;z-index:70;background:var(--shadow-ink)}
html.nav-open{overflow:hidden}
.site-footer{border-top:1px solid var(--border);background:linear-gradient(180deg,var(--bg),var(--bg-bottom));padding-top:56px;padding-bottom:32px}
.footer-grid{display:grid;grid-template-columns:1.2fr 1fr 1fr;gap:48px}
.footer-grid>*{min-width:0}
.footer-brand p{margin-top:16px;max-width:32em;font-size:14px;color:var(--muted)}
.footer-title{font-size:14px;font-weight:700;margin-bottom:12px}
.footer-links{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:4px 16px;font-size:13px}
.footer-links a,.footer-languages a,.legal-links a{display:inline-flex;align-items:center;min-height:28px}
.footer-links a:hover,.footer-languages a:hover,.legal-links a:hover{color:var(--accent-dark);text-decoration:underline}
.footer-languages{display:flex;flex-wrap:wrap;gap:8px 20px;margin-top:32px;font-size:13px}
.footer-bottom{display:flex;justify-content:space-between;flex-wrap:wrap;gap:16px;margin-top:24px;padding-top:24px;border-top:1px solid var(--border);font-size:12px;color:var(--muted)}
.legal-links{display:flex;flex-wrap:wrap;gap:16px}
.prose{min-width:0;font-size:16px;line-height:1.9}
.prose h2{margin-top:48px;margin-bottom:20px}
.prose h3{margin-top:32px;margin-bottom:16px}
.prose p,.prose ul,.prose ol,.prose pre,.prose blockquote{margin-block:18px}
.prose ul{list-style:disc;padding-left:24px}
.prose ol{list-style:decimal;padding-left:24px}
.prose a{color:var(--accent-dark);text-decoration:underline;text-underline-offset:3px}
.prose code{font-size:.88em;background:var(--panel-2);padding:2px 5px;border-radius:var(--r-key)}
.prose pre code{padding:0;background:none}
.reveal{transition:opacity .35s var(--ease-out),transform .35s var(--ease-out)}
.reveal.pending{opacity:0;transform:translateY(16px)}
.reveal.shown{opacity:1;transform:none}
#server-status{position:relative;display:block;min-width:0;max-width:100%;overflow:hidden;margin-block:32px}
#server-status>*{min-width:0;max-width:100%}
#server-status+*{margin-top:32px}
@media(max-width:1180px){
  .navlinks a{padding:6px 9px;font-size:13px}
  .navbox{gap:10px}
}
@media(max-width:1100px){
  .desktop-nav{display:none}
  .nav-toggle{display:flex}
  .nav-end{margin-left:auto}
  html.nav-open .nav-drawer{display:block}
}
@media(max-width:768px){
  :root{--space-section:56px}
  h1{font-size:38px;line-height:1.15}
  .grid-3,.grid-5{grid-template-columns:repeat(2,minmax(0,1fr))}
  .footer-grid{grid-template-columns:1fr 1fr;gap:32px}
  .footer-brand{grid-column:1/-1}
}
@media(max-width:640px){
  :root{--gutter:16px}
  .no-break{white-space:normal}
  .grid-2,.grid-3,.grid-5{grid-template-columns:minmax(0,1fr)}
  .brand{font-size:16px;gap:7px}
  .navbox{gap:4px;padding-left:10px}
  .lang{padding-inline:7px;font-size:11px}
  .lang svg{display:none}
  .login{padding-inline:12px;font-size:13px}
  .nav-end{gap:0;margin-left:auto}
  .nav-toggle{min-width:40px}
  .footer-grid{grid-template-columns:minmax(0,1fr)}
  .card{padding:20px}
  .tilt,.lockchip{transform:none}
  [data-hero-visual],.stripe-halo{max-width:100%}
}
@media(prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  .reveal,.reveal.pending,.reveal.shown{opacity:1;transform:none;transition:none}
  .btn,.navlinks a{transition:none}
}