:root{
  --bg:#EBEAF6;
  --panel:#F8F7FD;
  --groove:#DEDCEE;
  --border:#D3D1E4;
  --accent:#1E4D45;
  --accent-dark:#133630;
  --text:#1A1F2B;
  --muted:#5B6075;
  --success:#2F8F6A;
  --warn:#C27A2C;
  --error:#C2423A;
  --apricot:#F6DCC2;
  --apricot-line:#E4BB93;
  --apricot-glow:rgb(246 220 194 / .5);
  --fir-soft:#4E7A70;
  --mist:#C8C4E2;
  --wash-top:#F3F2FB;
  --wash-bottom:#E3E1F1;
  --fir-wash:rgb(30 77 69 / .05);
  --panel-glass:rgb(248 247 253 / .86);
  --groove-soft:rgb(222 220 238 / .6);
  --on-accent:#F8F7FD;
  --hl:rgb(255 255 255 / .6);
  --gloss:rgb(255 255 255 / .18);
  --accent-ring:rgb(30 77 69 / .16);
  --success-ring:rgb(47 143 106 / .2);
  --shadow-tint:rgb(30 77 69 / .10);
  --shadow-tint-2:rgb(30 77 69 / .06);
  --shadow-tint-3:rgb(30 77 69 / .16);
  --tag-shadow-color:rgb(30 77 69 / .22);
  --cta-shadow-color:rgb(30 77 69 / .55);
  --veil-color:rgb(26 31 43 / .28);
  --flag-red:#C8323C;
  --flag-blue:#22356F;
  --flag-white:#FFFFFF;
  --flag-edge:rgb(26 31 43 / .14);
  --shadow-float:0 30px 60px -18px var(--shadow-tint),0 12px 26px -14px var(--shadow-tint),0 2px 4px var(--shadow-tint-2);
  --shadow-float-up:0 40px 72px -18px var(--shadow-tint-3),0 16px 30px -14px var(--shadow-tint),0 2px 4px var(--shadow-tint-2);
  --shadow-chip:0 8px 18px -10px var(--shadow-tint-3),0 1px 2px var(--shadow-tint-2);
  --shadow-tag:0 12px 26px -12px var(--tag-shadow-color);
  --shadow-cta:0 16px 30px -14px var(--cta-shadow-color);
  --r-xs:6px;
  --r-sm:10px;
  --r-md:14px;
  --r-lg:20px;
  --r-pill:999px;
  --r-circle:50%;
  --f-display:"Iowan Old Style","Charter","Palatino Linotype",Georgia,"Songti SC","STSong","Noto Serif SC","SimSun",serif;
  --f-body:"Inter","Noto Sans SC","Noto Sans JP","Noto Sans KR","PingFang SC","Microsoft YaHei",system-ui,sans-serif;
  --f-mono:"JetBrains Mono","SFMono-Regular",Menlo,Consolas,monospace;
  --fs-body:15px;
  --fs-small:13px;
  --fs-h1:clamp(52px,4.6vw,72px);
  --fs-h2:clamp(28px,3vw,42px);
  --fs-h3:26px;
  --gutter:40px;
  --wrap:1280px;
  --head-height:72px;
  --anchor-space:88px;
  --toc-space:152px;
  --section-space:88px;
  --ease:ease;
  --quick:.2s;
  --normal:.3s;
}
*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-padding-top:var(--anchor-space);scroll-behavior:smooth}
html.nav-open{overflow:hidden}
body{margin:0;background:var(--bg);color:var(--text);font-family:var(--f-body);font-size:var(--fs-body);line-height:1.5;-webkit-font-smoothing:antialiased}
a{color:inherit}
button,input,select,textarea{font:inherit}
button{cursor:pointer}
button,summary,a{-webkit-tap-highlight-color:var(--accent-ring)}
button:disabled{cursor:not-allowed}
img{max-width:100%;height:auto}
svg{flex-shrink:0}
p{margin:0}
h1,h2,h3{font-family:var(--f-display);font-weight:400;line-height:1.2;text-wrap:balance;overflow-wrap:break-word}
h1{font-size:var(--fs-h1);line-height:1.12;letter-spacing:-.02em}
h2{font-size:var(--fs-h2)}
h3{font-size:var(--fs-h3)}
:focus-visible{outline:2px solid var(--accent);outline-offset:3px}
[hidden]{display:none!important}
.wrap{width:100%;max-width:var(--wrap);margin-inline:auto;padding-inline:var(--gutter)}
.sec{padding-top:var(--section-space);padding-bottom:var(--section-space)}
.no-break{white-space:nowrap}
.mono{font-family:var(--f-mono)}
.muted{color:var(--muted)}
.kw{color:var(--accent)}
.sprite{position:absolute;width:0;height:0;overflow:hidden}
.ic{width:20px;height:20px;display:inline-block;vertical-align:middle}
.fl{width:21px;height:14px;display:inline-block;vertical-align:middle;border-radius:var(--r-xs);overflow:hidden}
.grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:24px}
.grid>*{min-width:0}
.stack{display:grid;gap:24px}
.panel,.card{min-width:0;border:1px solid var(--border);border-radius:var(--r-md);background:var(--panel);padding:28px;box-shadow:var(--shadow-float),inset 0 0 0 1px var(--hl)}
.card{transition:transform var(--normal),box-shadow var(--normal)}
.card:hover{transform:translateY(-4px);box-shadow:var(--shadow-float-up)}
.section-head{max-width:760px;margin-bottom:32px}
.section-head h2{margin:0 0 16px}
.section-head p{color:var(--muted);line-height:1.8}
.prose{max-width:840px;min-width:0;line-height:1.85;overflow-wrap:break-word}
.prose p,.prose ul,.prose ol,.prose pre,.prose blockquote{margin-block:20px}
.prose h2{margin-top:48px;margin-bottom:20px}
.prose h3{margin-top:32px;margin-bottom:16px}
.prose a{color:var(--accent);text-underline-offset:4px}
code{font-family:var(--f-mono);font-size:.9em;overflow-wrap:anywhere;background:var(--groove-soft);border-radius:var(--r-xs);padding:2px 5px}
pre{max-width:100%;min-width:0;overflow-x:auto;background:var(--groove);border:1px solid var(--border);border-radius:var(--r-sm);padding:20px}
pre code{white-space:pre;overflow-wrap:normal;background:transparent;padding:0}
.btn,.btn-login{display:inline-flex;align-items:center;justify-content:center;flex-shrink:0;white-space:nowrap;text-decoration:none;border-radius:var(--r-pill);font-weight:560;transition:transform var(--quick),box-shadow var(--quick),background-color var(--quick),color var(--quick)}
.btn{gap:10px;min-height:52px;padding:12px 28px;font-size:16px;border:1.5px solid transparent}
.btn svg{width:18px;height:18px;display:block}
.btn-solid,.btn-primary{color:var(--on-accent);background:linear-gradient(180deg,var(--accent),var(--accent-dark));box-shadow:var(--shadow-cta),inset 0 1px 0 var(--gloss)}
.btn-solid:hover,.btn-primary:hover{transform:translateY(-1px)}
.btn-ghost,.btn-secondary{color:var(--text);border-color:var(--text);background:transparent}
.btn-ghost:hover,.btn-secondary:hover{background:var(--text);color:var(--on-accent)}
.btn:active{transform:translateY(1px)}
.btn:disabled,.btn[aria-disabled="true"]{opacity:.5;box-shadow:none;pointer-events:none}
.btn-small{min-height:40px;padding:8px 20px;font-size:14px}
.cta-row{display:flex;flex-wrap:wrap;gap:14px;margin-top:28px}
.reveal{transition:opacity .55s var(--ease),transform .55s var(--ease)}
.reveal.pending{opacity:0;transform:translateY(16px)}
.reveal.shown{opacity:1;transform:none}
#server-status{position:static;display:block;min-height:120px;min-width:0;max-width:100%;overflow:hidden;margin-block:24px}
#server-status+*{margin-top:32px}
#server-status>*{min-width:0;max-width:100%}
.decor-zone{position:relative;overflow-x:clip}
.site-head{position:sticky;top:0;z-index:20;height:var(--head-height);background:var(--panel-glass);-webkit-backdrop-filter:blur(14px);backdrop-filter:blur(14px);border-bottom:1px solid var(--border)}
.head-in{max-width:1360px;height:100%;margin:0 auto;padding-inline:var(--gutter);display:flex;align-items:center;gap:28px}
.brand{display:flex;align-items:center;gap:10px;text-decoration:none;color:var(--text);flex:none}
.brand-mark{width:34px;height:34px;border-radius:var(--r-circle);display:block;flex-shrink:0}
.brand-word{font-size:19px;font-weight:650;letter-spacing:.05em}
.brand-zh{font-weight:400;color:var(--muted)}
.nav{margin:0 auto}
.nav-list{display:flex;align-items:center;gap:2px;list-style:none;margin:0;padding:0}
.nav-list a{display:block;padding:8px 14px;border-radius:var(--r-pill);color:var(--muted);font-size:14.5px;text-decoration:none;transition:color var(--quick),background-color var(--quick)}
.nav-list a:hover{color:var(--text);background:var(--groove-soft)}
.nav-list a[aria-current="page"]{color:var(--text);font-weight:600;background:var(--groove);box-shadow:inset 0 0 0 1px var(--border)}
.head-tools{display:flex;align-items:center;gap:12px;flex:none}
.lang-box{position:relative}
.lang{display:inline-flex;align-items:center;justify-content:center;gap:6px;min-width:44px;width:auto;height:38px;padding:0 10px;border:0;border-radius:var(--r-pill);background:transparent;color:var(--muted);font-size:14px}
.lang span{white-space:nowrap}
.lang:hover{color:var(--text);background:var(--groove-soft)}
.lang svg{width:16px;height:16px;display:block}
.lang-menu{position:absolute;top:calc(100% + 12px);right:0;min-width:180px;padding:8px;list-style:none;margin:0;border:1px solid var(--border);border-radius:var(--r-sm);background:var(--panel);box-shadow:var(--shadow-float)}
.lang-menu a{display:flex;align-items:center;min-height:44px;padding:8px 12px;border-radius:var(--r-xs);text-decoration:none}
.lang-menu a:hover,.lang-menu a[aria-current="true"]{background:var(--groove)}
.btn-login{height:40px;padding:0 24px;border:1.5px solid var(--text);color:var(--text);font-size:14.5px}
.btn-login:hover{background:var(--text);color:var(--on-accent)}
.menu-toggle{display:none;align-items:center;justify-content:center;min-width:44px;min-height:44px;padding:8px;border:1px solid var(--border);border-radius:var(--r-sm);color:var(--text);background:var(--panel)}
.menu-toggle svg{width:22px;height:22px}
.mobile-nav{position:absolute;top:var(--head-height);left:0;right:0;z-index:22;background:var(--panel);padding:16px var(--gutter);max-height:calc(100dvh - var(--head-height));overflow-y:auto;overscroll-behavior:contain;box-shadow:var(--shadow-float)}
.mobile-nav ul{list-style:none;margin:0;padding:0}
.mobile-nav a{display:flex;align-items:center;width:100%;min-height:44px;padding:12px 16px;text-decoration:none;border-radius:var(--r-sm)}
.mobile-nav a:hover,.mobile-nav a[aria-current]{background:var(--groove);color:var(--accent-dark)}
.drawer-languages{margin-top:16px;border-top:1px solid var(--border);padding-top:12px}
.drawer-languages p{color:var(--muted);padding:8px 16px}
.nav-veil{position:fixed;inset:var(--head-height) 0 0;z-index:19;border:0;background:var(--veil-color)}
.site-foot{border-top:1px solid var(--border);background:var(--groove-soft);padding-top:56px;padding-bottom:32px}
.foot-grid{display:grid;grid-template-columns:1.4fr 1fr 1fr;gap:48px}
.foot-grid>*{min-width:0}
.foot-intro{max-width:340px;margin-top:20px;color:var(--muted);line-height:1.9}
.foot-title{font-family:var(--f-mono);font-size:var(--fs-small);font-weight:500;margin:0 0 16px;color:var(--accent)}
.foot-links{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:6px 16px;list-style:none;padding:0;margin:0}
.foot-links a,.foot-languages a,.foot-legal a{display:inline-flex;align-items:center;min-height:32px;text-decoration:none;color:var(--text)}
.foot-links a:hover,.foot-languages a:hover,.foot-legal a:hover{text-decoration:underline;text-underline-offset:4px}
.foot-bottom{margin-top:40px;padding-top:24px;border-top:1px solid var(--border);display:flex;flex-wrap:wrap;align-items:center;gap:16px 32px;color:var(--muted);font-size:var(--fs-small)}
.foot-languages,.foot-legal{display:flex;flex-wrap:wrap;gap:8px 20px}
.foot-copyright{font-family:var(--f-mono)}
@media(max-width:1200px){
  .head-in{gap:16px}
  .nav-list a{padding-inline:10px;font-size:13px}
  .head-tools{gap:6px}
}
@media(max-width:1080px){
  .nav{display:none}
  .head-tools{margin-left:auto}
  .menu-toggle{display:inline-flex}
  .foot-grid{gap:28px}
}
@media(min-width:1081px){.mobile-nav,.nav-veil{display:none!important}}
@media(max-width:768px){
  :root{--gutter:24px;--section-space:56px;--fs-h1:clamp(28px,5vw,40px)}
  .grid{grid-template-columns:repeat(2,minmax(0,1fr))}
  .foot-grid{grid-template-columns:1fr 1fr}
  .foot-brand{grid-column:1/-1}
}
@media(max-width:640px){
  :root{--gutter:16px}
  .no-break{white-space:normal}
  .tilt{transform:none}
  .decor-zone{max-width:100%}
  .head-in{gap:8px}
  .brand-word{font-size:16px}
  .brand-mark{width:30px;height:30px}
  .brand{gap:6px}
  .head-tools{margin-left:auto;gap:4px}
  .btn-login{padding-inline:14px}
  .lang{padding-inline:8px}
  .lang-desktop-label{display:none}
  .grid,.foot-grid{grid-template-columns:minmax(0,1fr)}
  .foot-brand{grid-column:auto}
  .panel,.card{padding:20px}
  .btn{padding-inline:22px}
}
@media(prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  *,*::before,*::after{animation:none!important;transition:none!important}
  .reveal,.reveal.pending{opacity:1;transform:none}
}