:root{
  --bg:#F4EFE4;
  --bg-panel:#FFFDF8;
  --bg-panel2:#ECE5D6;
  --bg-panel-deep:#FBF7EE;
  --border:#E2D9C7;
  --border-strong:#D3C7AF;
  --rail:#E2D9C7;
  --mark:#B4A68E;
  --accent:#2E3A33;
  --accent-dark:#1C241F;
  --accent-soft:#56685C;
  --text:#2A241C;
  --text-muted:#766B5C;
  --success:#3F7D4E;
  --warn:#B7791F;
  --error:#B3412E;
  --white:#FFFFFF;
  --on-ink:#FFFFFF;
  --hero-top:#F8F4EB;
  --hero-bottom:#EFE8DA;
  --ghost-bg:rgba(255,253,248,.62);
  --glow:rgba(46,58,51,.07);
  --shadow-ink-6:rgba(46,58,51,.06);
  --shadow-ink-10:rgba(46,58,51,.10);
  --shadow-ink-14:rgba(46,58,51,.14);
  --shadow-ink-40:rgba(28,36,31,.40);
  --ink-hilite:rgba(255,255,255,.16);
  --white-hi:rgba(255,255,255,.95);
  --white-edge:rgba(255,255,255,.55);
  --veil-color:rgba(28,36,31,.40);
  --flag-red:#C7372F;
  --flag-blue:#2C3F75;
  --flag-green:#2F7A45;
  --flag-white:#FFFFFF;
  --flag-edge:rgba(42,36,28,.16);
  --clear:transparent;
  --grad-ink:linear-gradient(112deg,var(--accent) 0%,var(--accent) 38%,var(--accent-soft) 100%);
  --grad-ink-cell:linear-gradient(150deg,var(--accent) 0%,var(--accent-soft) 100%);
  --grain:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='160' height='160'%3E%3Cfilter id='g'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='.85' numOctaves='2' stitchTiles='stitch'/%3E%3CfeColorMatrix values='0 0 0 0 .29 0 0 0 0 .22 0 0 0 0 .14 1 0 0 0 0'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23g)' opacity='.03'/%3E%3C/svg%3E");
  --shadow-lift:0 18px 40px var(--shadow-ink-10),0 2px 4px var(--shadow-ink-6);
  --shadow-float:0 14px 28px -8px var(--shadow-ink-14),0 1px 2px var(--shadow-ink-10);
  --hilite:inset 0 1px 0 var(--white-hi);
  --groove:inset 0 1px 2px var(--shadow-ink-10);
  --radius-xs:4px;
  --radius-sm:6px;
  --radius-md:8px;
  --radius-lg:10px;
  --radius-pill:999px;
  --radius-round:50%;
  --sheet:1344px;
  --reading:800px;
  --gutter:48px;
  --header-height:72px;
  --anchor-offset:88px;
  --toc-offset:84px;
  --toc-landing:156px;
  --font-display:"Inter","Noto Sans SC","PingFang SC","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;
  --size-xs:12px;
  --size-sm:14px;
  --size-body:16px;
  --size-lead:18px;
  --size-h3:22px;
  --size-h2:clamp(28px,3vw,40px);
  --size-h1:clamp(52px,4.6vw,66px);
  --weight-normal:400;
  --weight-medium:500;
  --weight-semibold:600;
  --weight-bold:700;
  --weight-heavy:800;
  --weight-display:900;
  --space-1:8px;
  --space-2:16px;
  --space-3:24px;
  --space-4:32px;
  --space-6:48px;
  --space-8:64px;
  --space-10:80px;
  --ease-out:cubic-bezier(.2,.7,.3,1);
  --reveal-time:.35s;
}
*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-padding-top:var(--anchor-offset);scroll-behavior:smooth}
body{margin:0;font-family:var(--font-body);font-size:var(--size-body);line-height:1.6;color:var(--text);background:var(--grain),var(--bg);-webkit-font-smoothing:antialiased}
a{color:inherit;text-decoration:none}
button,input,select,textarea{font:inherit;color:inherit}
button{background:none;border:0;padding:0;cursor:pointer}
button:disabled{cursor:not-allowed}
img{display:block;max-width:100%;height:auto}
svg{display:block;flex-shrink:0}
p,h1,h2,h3,h4,figure,blockquote{margin:0}
ul{list-style:none;margin:0;padding:0}
ol{padding-left:1.5em}
h1,h2,h3,h4{font-family:var(--font-display);text-wrap:balance}
h1{font-size:var(--size-h1);font-weight:var(--weight-display);line-height:1.12;letter-spacing:-.02em}
h2{font-size:var(--size-h2);font-weight:var(--weight-heavy);line-height:1.25;letter-spacing:-.02em}
h3{font-size:var(--size-h3);font-weight:var(--weight-bold);line-height:1.35}
:focus-visible{outline:2px solid var(--accent);outline-offset:3px;border-radius:var(--radius-xs)}
[hidden]{display:none!important}
.no-break{white-space:nowrap}
code{font-family:var(--font-mono);font-size:.9em;overflow-wrap:anywhere}
pre{max-width:100%;overflow-x:auto;padding:var(--space-3);background:var(--bg-panel2);border:1px solid var(--border);border-radius:var(--radius-md)}
pre code{overflow-wrap:normal;white-space:pre}
input,select,textarea{max-width:100%;padding:12px 14px;background:var(--bg-panel);border:1px solid var(--border-strong);border-radius:var(--radius-sm)}
input:focus-visible,textarea:focus-visible{outline-color:var(--accent)}
::selection{background:var(--bg-panel2);color:var(--accent-dark)}
.sheet,.wrap{position:relative;max-width:var(--sheet);margin-inline:auto;padding-inline:var(--gutter)}
.sheet{border-left:1px solid var(--rail);border-right:1px solid var(--rail)}
.reading-wrap{max-width:var(--reading);margin-inline:auto;padding-inline:var(--gutter)}
.section{padding-top:var(--space-8);padding-bottom:var(--space-8)}
.section-rule{border-top:1px solid var(--rail);overflow-x:clip}
.section-head{margin-bottom:var(--space-4)}
.section-head h2{margin-top:var(--space-2)}
.section-head p{margin-top:var(--space-2);color:var(--text-muted);max-width:48em}
.centered{text-align:center}
.centered p{margin-inline:auto}
.stack{display:grid;gap:var(--space-3)}
.row{display:flex;align-items:center;gap:var(--space-2);flex-wrap:wrap}
.grid-two{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:var(--space-3)}
.grid-three{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:var(--space-3)}
.grid-two>*,.grid-three>*,.sheet>*,.wrap>*{min-width:0}
.muted{color:var(--text-muted)}
.mono{font-family:var(--font-mono);font-variant-numeric:tabular-nums}
.panel,.card{min-width:0;background:var(--bg-panel);border:1px solid var(--border);border-radius:var(--radius-lg);box-shadow:var(--hilite),var(--shadow-lift)}
.card{padding:var(--space-3)}
.inset{background:var(--bg-panel2);border-radius:var(--radius-md);box-shadow:var(--groove);padding:var(--space-2)}
.icon{width:20px;height:20px;color:currentColor;fill:none;stroke:currentColor;stroke-width:1.7;stroke-linecap:round;stroke-linejoin:round}
.icon-defs{position:absolute;width:0;height:0;overflow:hidden;pointer-events:none}
.btn,.btn-primary,.btn-secondary,.btn-ink,.btn-ghost{display:inline-flex;align-items:center;justify-content:center;gap:10px;min-height:48px;padding:10px 24px;border-radius:var(--radius-pill);font-size:var(--size-sm);font-weight:var(--weight-semibold);line-height:1.4;flex-shrink:0;white-space:nowrap}
.btn-primary,.btn-ink{background:var(--grad-ink);color:var(--on-ink);box-shadow:0 16px 28px -12px var(--shadow-ink-40),inset 0 1px 0 var(--ink-hilite)}
.btn-primary:hover,.btn-ink:hover{box-shadow:0 18px 32px -10px var(--shadow-ink-40),inset 0 1px 0 var(--ink-hilite)}
.btn-primary:active,.btn-ink:active{background:var(--accent-dark)}
.btn-secondary,.btn-ghost{background:var(--ghost-bg);border:1px solid var(--border-strong);box-shadow:var(--hilite)}
.btn-secondary:hover,.btn-ghost:hover{background:var(--bg-panel)}
.btn-secondary:active,.btn-ghost:active{background:var(--bg-panel2)}
.btn:disabled,.btn-primary:disabled,.btn-secondary:disabled,[aria-disabled="true"]{opacity:.55;cursor:not-allowed}
.btn svg,.btn-primary svg,.btn-secondary svg{width:20px;height:20px}
.text-link{display:inline-flex;align-items:center;gap:6px;min-height:28px;text-decoration:underline;text-underline-offset:4px;font-weight:var(--weight-semibold)}
.brand{display:inline-flex;align-items:center;gap:10px;font-family:var(--font-display);font-size:19px;font-weight:var(--weight-heavy);letter-spacing:-.02em;color:var(--text);white-space:nowrap}
.brand-zh{font-weight:var(--weight-medium);color:var(--text-muted)}
.logo-mark{width:30px;height:30px;flex-shrink:0}
.topbar{position:relative;z-index:50;background:var(--bg)}
.topbar-inner{height:var(--header-height);display:grid;grid-template-columns:auto minmax(0,1fr) auto;align-items:center;column-gap:32px}
.mainnav{min-width:0;flex:1}
.mainnav-list{display:flex;justify-content:center;align-items:center;list-style:none;margin:0;padding:0;gap:4px}
.mainnav-link{display:inline-flex;align-items:center;gap:6px;height:36px;padding:0 14px;border-radius:var(--radius-md);font-size:15px;font-weight:var(--weight-medium);color:var(--text);white-space:nowrap}
.mainnav-link:hover{background:var(--ghost-bg)}
.mainnav-link.is-active{background:var(--bg-panel2);box-shadow:var(--groove);font-weight:var(--weight-semibold)}
.mainnav-link svg{width:12px;height:12px;color:var(--text-muted)}
.mainnav-more{position:relative}
.more-menu{position:absolute;top:calc(100% + 10px);left:50%;min-width:212px;margin-left:-106px;padding:8px;display:none;z-index:55;background:var(--bg-panel);border:1px solid var(--border);border-radius:var(--radius-lg);box-shadow:var(--shadow-lift),var(--hilite)}
.mainnav-more.is-open .more-menu{display:block}
.more-group{padding:8px 10px 4px;font-family:var(--font-mono);font-size:11px;letter-spacing:.06em;color:var(--text-muted)}
.more-link{display:flex;align-items:center;min-height:36px;padding:7px 10px;border-radius:var(--radius-sm);font-size:var(--size-sm)}
.more-link:hover,.more-link.is-active{background:var(--bg-panel2)}
.topbar-tools{display:flex;align-items:center;gap:8px;justify-self:end;flex-shrink:0;flex-wrap:nowrap}
.language-box{position:relative}
.lang-switch{display:inline-flex;align-items:center;justify-content:center;gap:6px;min-height:36px;min-width:44px;width:auto;padding:0 12px;border-radius:var(--radius-md);font-size:var(--size-sm);color:var(--text-muted);white-space:nowrap}
.lang-label{white-space:nowrap}
.lang-switch:hover{background:var(--ghost-bg);color:var(--text)}
.lang-switch svg{width:15px;height:15px}
.language-panel{display:none;position:absolute;right:0;top:calc(100% + 10px);z-index:60;min-width:176px;padding:8px;background:var(--bg-panel);border:1px solid var(--border);border-radius:var(--radius-lg);box-shadow:var(--shadow-lift)}
.language-box.is-open .language-panel{display:block}
.language-link{display:flex;align-items:center;min-height:40px;padding:8px 12px;border-radius:var(--radius-sm);font-size:var(--size-sm);white-space:nowrap}
.language-link:hover,.language-link.is-active{background:var(--bg-panel2);color:var(--accent-dark)}
.login-btn{display:inline-flex;align-items:center;justify-content:center;gap:6px;height:38px;padding:0 12px 0 16px;border-radius:var(--radius-md);background:var(--accent);color:var(--on-ink);font-size:var(--size-sm);font-weight:var(--weight-semibold);box-shadow:0 6px 14px -6px var(--shadow-ink-40),inset 0 1px 0 var(--ink-hilite);white-space:nowrap}
.login-btn:hover{background:var(--accent-dark)}
.login-btn svg{width:12px;height:12px}
.menu-toggle{display:none;align-items:center;justify-content:center;min-width:44px;min-height:44px;border:1px solid var(--border);border-radius:var(--radius-md)}
.menu-toggle svg{width:20px;height:20px;fill:none;stroke:currentColor;stroke-width:1.8;stroke-linecap:round}
.menu-line{display:block}
.mobile-drawer{display:none}
.nav-veil{display:none}
html.nav-open{overflow:hidden}
.site-footer{border-top:1px solid var(--rail);background:var(--grain),var(--bg-panel2)}
.footer-grid{display:grid;grid-template-columns:1.4fr 1fr 1fr;gap:var(--space-6);padding-top:var(--space-6);padding-bottom:var(--space-4)}
.footer-brand p{max-width:29em;margin-top:var(--space-2);font-size:var(--size-sm);color:var(--text-muted)}
.footer-heading{font-size:var(--size-sm);font-weight:var(--weight-bold);margin-bottom:12px}
.footer-links{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:6px 16px}
.footer-links a,.footer-languages a,.footer-legal a{display:inline-flex;align-items:center;min-height:28px;font-size:var(--size-sm)}
.footer-links a:hover,.footer-languages a:hover,.footer-legal a:hover{text-decoration:underline;text-underline-offset:4px}
.footer-languages{display:flex;flex-wrap:wrap;gap:8px 20px;padding-top:var(--space-2);padding-bottom:var(--space-2);border-top:1px solid var(--border-strong)}
.footer-bottom{display:flex;justify-content:space-between;gap:16px;flex-wrap:wrap;padding-top:var(--space-2);padding-bottom:var(--space-3);border-top:1px solid var(--border-strong);color:var(--text-muted);font-size:var(--size-xs)}
.footer-legal{display:flex;gap:16px;flex-wrap:wrap}
.prose{min-width:0;line-height:1.85}
.prose p,.prose ul,.prose ol,.prose pre,.prose blockquote{margin-top:var(--space-2);margin-bottom:var(--space-3)}
.prose h2{margin-top:var(--space-6);margin-bottom:var(--space-2)}
.prose h3{margin-top:var(--space-4);margin-bottom:12px}
.prose ul{list-style:disc;padding-left:1.5em}
.prose a{color:var(--accent);text-decoration:underline;text-underline-offset:3px}
.prose li+li{margin-top:8px}
.prose img{border-radius:var(--radius-md)}
.reveal{transition:opacity var(--reveal-time) var(--ease-out),transform var(--reveal-time) 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-top:var(--space-3);margin-bottom:var(--space-3)}
#server-status+*{margin-top:var(--space-3)}
#server-status>*{min-width:0;max-width:100%}
.decorated-section{position:relative;overflow-x:clip}
.cross{position:absolute;width:17px;height:17px;z-index:3;pointer-events:none}
.cross::before,.cross::after{content:"";position:absolute;background:var(--mark)}
.cross::before{left:0;right:0;top:8px;height:1px}
.cross::after{top:0;bottom:0;left:8px;width:1px}
.cross-tl{top:-9px;left:-9px}
.cross-tr{top:-9px;right:-9px}
.cross-bl{bottom:-9px;left:-9px}
.cross-br{bottom:-9px;right:-9px}
@media(max-width:1100px){
  .mainnav-link{padding:0 10px}
  .topbar-inner{column-gap:16px}
}
@media(max-width:900px){
  .mainnav{display:none}
  .topbar-inner{display:flex;flex-wrap:nowrap}
  .topbar-tools{margin-left:auto}
  .menu-toggle{display:inline-flex}
  .mobile-drawer{position:fixed;top:var(--header-height);right:0;left:0;z-index:45;height:calc(100dvh - var(--header-height));max-height:calc(100dvh - var(--header-height));padding:16px var(--gutter) 32px;background:var(--bg-panel);overflow-y:auto;overscroll-behavior:contain;border-top:1px solid var(--border)}
  .mobile-drawer.is-open{display:block}
  .mobile-drawer a{display:flex;align-items:center;width:100%;min-height:44px;padding:12px 16px;border-radius:var(--radius-sm);font-size:var(--size-sm)}
  .mobile-drawer a:hover,.mobile-drawer a.is-active{background:var(--bg-panel2)}
  .drawer-languages{border-top:1px solid var(--border);margin-top:16px;padding-top:12px}
  .nav-veil{position:fixed;top:var(--header-height);inset-inline:0;bottom:0;z-index:40;background:var(--veil-color)}
  .nav-veil.is-open{display:block}
}
@media(max-width:768px){
  :root{--gutter:20px;--header-height:64px;--anchor-offset:80px;--toc-offset:12px;--toc-landing:96px;--size-h1:38px}
  .sheet{border-left:0;border-right:0}
  .cross{display:none}
  .topbar-inner{column-gap:12px}
  .grid-three{grid-template-columns:minmax(0,1fr)}
  .footer-grid{grid-template-columns:minmax(0,1fr) minmax(0,1fr);gap:32px}
  .footer-brand{grid-column:1/-1}
  .section{padding-top:var(--space-6);padding-bottom:var(--space-6)}
}
@media(max-width:640px){
  .no-break{white-space:normal}
  .grid-two{grid-template-columns:minmax(0,1fr)}
  .tilt,.luggage-tag{transform:none}
  .decorated-section{max-width:100%;overflow-x:clip}
  .brand{font-size:16px;gap:7px}
  .logo-mark{width:26px;height:26px}
  .topbar-tools{gap:4px;margin-left:auto}
  .lang-switch{padding:0 6px;gap:4px;font-size:11px}
  .lang-switch svg{width:13px;height:13px}
  .login-btn{padding:0 10px;height:36px;font-size:12px}
  .login-btn svg{display:none}
  .topbar-inner{column-gap:6px}
  .footer-grid{grid-template-columns:minmax(0,1fr)}
  .footer-brand{grid-column:auto}
  .reading-wrap{padding-inline:var(--gutter)}
}
@media(max-width:359px){
  :root{--gutter:16px}
  .brand{font-size:15px;gap:5px}
  .brand .logo-mark{width:24px;height:24px}
  .lang-switch{padding:0 4px}
  .lang-switch svg{display:none}
}
@media(prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  .reveal,.reveal.pending,.reveal.shown{opacity:1;transform:none;transition:none}
}