:root{
  --color-bg:#E7EEF8;
  --color-panel:#F7FAFE;
  --color-panel-alt:#DCE6F3;
  --color-border:#C3D2E6;
  --color-accent:#2F5D9E;
  --color-accent-dark:#1C3E70;
  --color-text:#17233B;
  --color-muted:#5A6B85;
  --color-success:#178A5C;
  --color-warning:#B97E14;
  --color-error:#C2453A;
  --color-white:#FFFFFF;
  --color-flag-red:#CE3B44;
  --color-flag-blue:#2C4B9B;
  --color-flag-navy:#24407E;
  --color-header:rgba(247,250,254,.82);
  --color-shadow-soft:rgba(23,35,59,.06);
  --color-shadow-mid:rgba(23,35,59,.07);
  --color-shadow-blue:rgba(28,62,112,.07);
  --color-button-shadow:rgba(28,62,112,.24);
  --color-focus-shadow:rgba(47,93,158,.22);
  --color-glow-blue:rgba(64,116,190,.20);
  --color-glow-cyan:rgba(45,152,168,.15);
  --color-glow-violet:rgba(126,112,200,.15);
  --color-halo:rgba(47,93,158,.30);
  --color-dot-glow:rgba(47,93,158,.55);
  --color-hero-atmo:rgba(220,230,243,.55);
  --font-display:'Inter','Noto Sans SC',-apple-system,'PingFang SC','Microsoft YaHei',sans-serif;
  --font-body:'Inter','Noto Sans SC',-apple-system,'PingFang SC','Microsoft YaHei',sans-serif;
  --font-mono:'JetBrains Mono','SFMono-Regular',Consolas,'Liberation Mono',monospace;
  --radius-xs:6px;
  --radius-sm:8px;
  --radius-md:12px;
  --radius-lg:20px;
  --radius-pill:999px;
  --shadow-soft:0 1px 2px var(--color-shadow-soft),0 6px 18px var(--color-shadow-soft);
  --shadow-card:0 1px 2px var(--color-shadow-soft),0 10px 28px var(--color-shadow-mid),0 30px 64px var(--color-shadow-blue);
  --shadow-button:0 1px 2px var(--color-focus-shadow),0 8px 20px var(--color-button-shadow);
  --header-height:64px;
  --content-width:1240px;
  --reading-width:800px;
  --gutter:32px;
  --section-space:96px;
  --toc-offset:132px;
  --transition-fast:150ms ease;
  --transition-base:420ms cubic-bezier(.2,.75,.25,1);
}
*,*::before,*::after{box-sizing:border-box}
html{scroll-behavior:smooth;scroll-padding-top:80px;background:var(--color-bg)}
html.nav-open{overflow:hidden}
body{margin:0;min-width:320px;background:var(--color-bg);color:var(--color-text);font-family:var(--font-body);font-size:16px;line-height:1.65;-webkit-font-smoothing:antialiased;overflow-x:clip}
body,input,button,select,textarea{font-family:var(--font-body)}
img,svg,video{display:block;max-width:100%}
img{height:auto}
a{color:inherit;text-decoration:none}
button{color:inherit}
ul,ol{margin:0;padding:0}
ul{list-style:none}
p,figure,blockquote,pre{margin:0}
h1,h2,h3,h4{margin:0;color:var(--color-text);font-family:var(--font-display);line-height:1.18;text-wrap:balance}
h1{font-size:clamp(52px,5.4vw,72px);font-weight:900;letter-spacing:-.02em}
h2{font-size:clamp(32px,4vw,48px);font-weight:900;letter-spacing:-.018em}
h3{font-size:clamp(21px,2.1vw,28px);font-weight:800}
h4{font-size:18px;font-weight:800}
p+ p{margin-top:1em}
strong{font-weight:750}
code,kbd,samp{font-family:var(--font-mono)}
code{overflow-wrap:anywhere}
pre{max-width:100%;overflow-x:auto;padding:20px;background:var(--color-text);color:var(--color-panel);border-radius:var(--radius-md);font:13px/1.7 var(--font-mono);-webkit-overflow-scrolling:touch}
::selection{background:var(--color-accent);color:var(--color-panel)}
:focus-visible{outline:2px solid var(--color-accent);outline-offset:3px}
.wrap,.container{width:100%;max-width:var(--content-width);margin-inline:auto;padding-inline:var(--gutter)}
.reading-wrap{width:100%;max-width:var(--reading-width);margin-inline:auto;padding-inline:var(--gutter)}
.section{padding-top:var(--section-space);padding-bottom:var(--section-space);overflow-x:clip}
.section-alt{background:var(--color-panel-alt)}
.section-head{max-width:760px;margin-bottom:42px}
.section-head.centered{margin-inline:auto;text-align:center}
.eyebrow{display:inline-flex;align-items:center;gap:9px;margin-bottom:14px;color:var(--color-accent-dark);font:700 12px/1.4 var(--font-mono);letter-spacing:.12em;text-transform:uppercase}
.eyebrow::before{content:"";width:8px;height:8px;flex:0 0 auto;border-radius:50%;background:var(--color-success)}
.lead{margin-top:16px;color:var(--color-muted);font-size:clamp(17px,2vw,20px)}
.muted{color:var(--color-muted)}
.mono{font-family:var(--font-mono)}
.no-break{white-space:nowrap}
.grad-text{background:linear-gradient(118deg,var(--color-accent),var(--color-accent-dark));background-clip:text;-webkit-background-clip:text;color:transparent;-webkit-text-fill-color:transparent}
.panel,.card{min-width:0;background:var(--color-panel);border:1px solid var(--color-border);border-radius:var(--radius-md);box-shadow:var(--shadow-soft)}
.panel{padding:28px}
.card{padding:24px}
.stack>*+*{margin-top:16px}
.cluster{display:flex;flex-wrap:wrap;align-items:center;gap:12px}
.grid-2,.grid-3{display:grid;gap:24px}
.grid-2{grid-template-columns:repeat(2,minmax(0,1fr))}
.grid-3{grid-template-columns:repeat(3,minmax(0,1fr))}
.grid-2>*,.grid-3>*{min-width:0}
.btn{
  display:inline-flex;
  min-height:48px;
  min-width:24px;
  align-items:center;
  justify-content:center;
  gap:8px;
  padding:12px 28px;
  border:1px solid transparent;
  border-radius:10px;
  font-family:var(--font-display);
  font-size:15px;
  font-weight:750;
  line-height:1.2;
  cursor:pointer;
  transition:transform var(--transition-fast),background var(--transition-fast),border-color var(--transition-fast),box-shadow var(--transition-fast)
}
.btn:hover{transform:translateY(-1px)}
.btn-primary{background:linear-gradient(180deg,var(--color-accent),var(--color-accent-dark));color:var(--color-panel);box-shadow:var(--shadow-button)}
.btn-secondary{background:var(--color-panel);color:var(--color-accent-dark);border-color:var(--color-border);box-shadow:var(--shadow-soft)}
.btn-secondary:hover{border-color:var(--color-accent)}
.btn-small{min-height:40px;padding:9px 18px;font-size:14px}
.btn[aria-disabled="true"],.btn:disabled{cursor:not-allowed;opacity:.55;transform:none}
.badge,.tag{
  display:inline-flex;
  max-width:100%;
  min-height:26px;
  align-items:center;
  gap:7px;
  overflow:hidden;
  padding:4px 10px;
  border:1px solid var(--color-border);
  border-radius:var(--radius-pill);
  background:var(--color-panel);
  color:var(--color-accent-dark);
  font:700 12px/1.35 var(--font-mono)
}
.status-dot{width:8px;height:8px;flex:0 0 auto;border-radius:50%;background:var(--color-success)}
.reveal{transition:opacity var(--transition-base),transform var(--transition-base)}
.reveal.pending{opacity:0;transform:translateY(16px)}
.reveal.shown{opacity:1;transform:none}
.site-header{position:sticky;top:0;z-index:60;border-bottom:1px solid var(--color-border);background:var(--color-header);backdrop-filter:blur(10px)}
.header-row{position:relative;display:flex;height:var(--header-height);align-items:center;gap:24px}
.brand{display:inline-flex;min-height:44px;align-items:center;gap:9px;flex:0 0 auto}
.brand-logo{width:27px;height:27px;flex:0 0 auto}
.brand-name{font-family:var(--font-display);font-size:19px;font-weight:850;letter-spacing:-.01em}
.brand-local{color:var(--color-muted);font-size:14px;font-weight:600}
.desktop-nav{display:flex;min-width:0;flex:1 1 auto;align-items:center;justify-content:center}
.desktop-nav li{display:flex;align-items:center}
.desktop-nav li+li::before{content:"·";margin-inline:11px;color:var(--color-border);font-weight:800}
.desktop-nav a{display:inline-flex;min-height:36px;align-items:center;color:var(--color-muted);font-size:13px;white-space:nowrap}
.desktop-nav a:hover,.desktop-nav a[aria-current="page"]{color:var(--color-accent-dark)}
.desktop-nav a[aria-current="page"]{font-weight:750}
.header-tools{display:flex;flex:0 0 auto;align-items:center;gap:10px}
.lang-control{position:relative}
.lang-button,.menu-button{min-width:44px;min-height:44px;border:0;background:transparent;cursor:pointer}
.lang-button{display:inline-flex;align-items:center;justify-content:center;padding-inline:7px;color:var(--color-muted);font-size:13px}
.lang-menu{position:absolute;top:calc(100% + 7px);right:0;z-index:70;display:none;width:164px;padding:7px;background:var(--color-panel);border:1px solid var(--color-border);border-radius:var(--radius-md);box-shadow:var(--shadow-card)}
.lang-menu.open{display:block}
.lang-menu a{display:flex;min-height:40px;align-items:center;padding:7px 10px;border-radius:var(--radius-xs);font-size:13px}
.lang-menu a:hover,.lang-menu a[aria-current="true"]{background:var(--color-panel-alt);color:var(--color-accent-dark)}
.login-link{display:inline-flex;min-height:38px;align-items:center;justify-content:center;padding:8px 17px;border-radius:var(--radius-sm);background:var(--color-accent);color:var(--color-panel);font-size:13px;font-weight:750;box-shadow:var(--shadow-soft)}
.login-link:hover{background:var(--color-accent-dark)}
.menu-button{display:none;align-items:center;justify-content:center;border-radius:var(--radius-sm)}
.menu-icon,.menu-icon::before,.menu-icon::after{display:block;width:20px;height:2px;background:var(--color-text);transition:transform var(--transition-fast)}
.menu-icon{position:relative}
.menu-icon::before,.menu-icon::after{content:"";position:absolute;left:0}
.menu-icon::before{top:-6px}
.menu-icon::after{top:6px}
.menu-button[aria-expanded="true"] .menu-icon{background:transparent}
.menu-button[aria-expanded="true"] .menu-icon::before{top:0;transform:rotate(45deg)}
.menu-button[aria-expanded="true"] .menu-icon::after{top:0;transform:rotate(-45deg)}
.mobile-nav{position:absolute;top:var(--header-height);left:0;right:0;z-index:66;display:none;max-height:calc(100dvh - var(--header-height));overflow-y:auto;padding:12px var(--gutter) 20px;background:var(--color-panel);border-bottom:1px solid var(--color-border);box-shadow:var(--shadow-card);overscroll-behavior:contain}
.mobile-nav.open{display:block}
.mobile-nav a{display:flex;width:100%;min-height:46px;align-items:center;padding:10px 12px;border-bottom:1px solid var(--color-border);color:var(--color-muted)}
.mobile-nav a[aria-current="page"]{color:var(--color-accent-dark);font-weight:750}
.mobile-language{margin-top:10px}
.mobile-language-label{padding:8px 12px;color:var(--color-muted);font:700 11px/1.4 var(--font-mono);letter-spacing:.1em}
.mobile-language a{font-size:14px}
.site-footer{overflow-x:clip;padding-top:64px;background:var(--color-text);color:var(--color-panel)}
.footer-grid{display:grid;grid-template-columns:minmax(230px,1.2fr) repeat(2,minmax(0,1fr));gap:48px}
.footer-brand p{max-width:360px;margin-top:16px;color:var(--color-border)}
.footer-brand .brand-name{color:var(--color-panel)}
.footer-title{margin-bottom:14px;color:var(--color-panel);font:750 12px/1.4 var(--font-mono);letter-spacing:.11em}
.footer-links{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:5px 18px}
.footer-links a,.footer-languages a{display:inline-flex;min-height:32px;align-items:center;color:var(--color-border);font-size:14px}
.footer-links a:hover,.footer-languages a:hover{color:var(--color-panel)}
.footer-languages{display:flex;flex-wrap:wrap;gap:4px 16px}
.footer-bottom{display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;gap:14px;margin-top:48px;padding-top:20px;padding-bottom:28px;border-top:1px solid var(--color-muted);color:var(--color-border);font-size:13px}
.footer-legal{display:flex;flex-wrap:wrap;gap:18px}
.prose{color:var(--color-text)}
.prose>*+*{margin-top:1.15em}
.prose h2{margin-top:2em}
.prose h3{margin-top:1.6em}
.prose ul,.prose ol{padding-left:1.4em}
.prose ul{list-style:disc}
.prose li+li{margin-top:.5em}
.prose a:not(.btn){color:var(--color-accent-dark);text-decoration:underline;text-underline-offset:3px}
.prose img{border-radius:var(--radius-md)}
body:has(.toc-tabs) section[id]{scroll-margin-top:var(--toc-offset)}
@media (max-width:1080px){
  .desktop-nav{display:none}
  .header-tools{margin-left:auto}
  .menu-button{display:inline-flex}
  .brand-local{display:none}
}
@media (max-width:768px){
  :root{--gutter:20px;--section-space:72px}
  h1{font-size:clamp(28px,9vw,40px);line-height:1.12}
  h2{font-size:clamp(28px,7vw,36px)}
  .grid-2,.grid-3{grid-template-columns:1fr}
  .footer-grid{grid-template-columns:1fr 1fr}
  .footer-brand{grid-column:1/-1}
}
@media (max-width:640px){
  :root{--gutter:16px;--section-space:60px}
  .wrap,.container,.reading-wrap{padding-inline:var(--gutter)}
  .header-row{gap:8px}
  .brand-name{font-size:17px}
  .lang-control{display:none}
  .login-link{min-height:36px;padding-inline:12px}
  .btn{width:100%}
  .cluster.actions{align-items:stretch;flex-direction:column}
  .footer-grid{grid-template-columns:1fr}
  .footer-brand{grid-column:auto}
  .footer-links{grid-template-columns:1fr 1fr}
  .tilt,.tilt-left,.tilt-right{transform:none}
}
@media (max-width:380px){
  .brand-logo{width:24px;height:24px}
  .login-link{padding-inline:10px}
}
@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  *,*::before,*::after{animation-duration:.01ms!important;animation-iteration-count:1!important;transition-duration:.01ms!important}
  .reveal,.reveal.pending{opacity:1;transform:none}
}