:root{
  --color-canvas:#E8F1F8;
  --color-surface:#F7FBFE;
  --color-surface-strong:#DCE8F3;
  --color-paper:#FFFFFF;
  --color-line:#C3D6E8;
  --color-brand:#0F62B5;
  --color-brand-deep:#0A4785;
  --color-ink:#12283C;
  --color-muted:#52708A;
  --color-success:#1E9E6A;
  --color-warning:#D9860B;
  --color-danger:#D64545;
  --color-brand-soft:rgba(15,98,181,.10);
  --color-brand-mid:rgba(15,98,181,.16);
  --color-success-soft:rgba(30,158,106,.14);
  --color-shadow:rgba(18,40,60,.07);
  --color-shadow-deep:rgba(15,98,181,.32);
  --color-focus:rgba(15,98,181,.28);
  --color-flag-red:#CB3B33;
  --color-flag-blue:#2E4A86;
  --color-flag-green:#2F8654;
  --color-flag-yellow:#F2C94C;
  --font-display:'Inter','Noto Sans SC','PingFang SC','Microsoft YaHei',-apple-system,sans-serif;
  --font-body:'Inter','Noto Sans SC','PingFang SC','Microsoft YaHei',-apple-system,sans-serif;
  --font-mono:'JetBrains Mono','SFMono-Regular',Consolas,'Courier New',monospace;
  --radius-xs:6px;
  --radius-sm:8px;
  --radius-md:10px;
  --radius-pill:999px;
  --shadow-card:0 1px 2px rgba(18,40,60,.05),0 10px 26px var(--color-shadow);
  --shadow-window:0 4px 10px rgba(18,40,60,.10),0 34px 64px -22px var(--color-shadow-deep);
  --shadow-button:0 2px 6px rgba(15,98,181,.28),0 10px 22px -8px rgba(15,98,181,.45);
  --header-height:64px;
  --content-width:1252px;
  --reading-width:820px;
  --gutter:24px;
  --section-space:88px;
  --toc-offset:80px;
  --duration-fast:150ms;
  --duration-base:260ms;
}
*,
*::before,
*::after{box-sizing:border-box}
html{
  min-width:320px;
  scroll-behavior:smooth;
  scroll-padding-top:calc(var(--header-height) + 16px);
  -webkit-text-size-adjust:100%;
}
html.nav-open{overflow:hidden}
body{
  min-height:100vh;
  margin:0;
  overflow-x:clip;
  background:var(--color-canvas);
  color:var(--color-ink);
  font-family:var(--font-body);
  font-size:16px;
  line-height:1.65;
}
img,svg,video{display:block;max-width:100%}
img{height:auto}
button,input,select,textarea{font:inherit}
button{cursor:pointer}
a{color:var(--color-brand);text-decoration:none}
a:hover{color:var(--color-brand-deep)}
p,ul,ol,dl,figure,blockquote,pre{margin:0 0 1.25rem}
h1,h2,h3,h4{
  margin:0 0 .7em;
  color:var(--color-ink);
  font-family:var(--font-display);
  line-height:1.16;
  text-wrap:balance;
}
h1{font-size:clamp(52px,5.25vw,68px);font-weight:900;letter-spacing:-.015em}
h2{font-size:clamp(32px,3.4vw,48px);font-weight:850;letter-spacing:-.012em}
h3{font-size:clamp(22px,2.2vw,30px);font-weight:800}
h4{font-size:19px;font-weight:750}
ul,ol{padding-left:1.4em}
code,kbd,samp{font-family:var(--font-mono)}
code{overflow-wrap:anywhere}
pre{
  max-width:100%;
  overflow-x:auto;
  padding:18px;
  border:1px solid var(--color-line);
  border-radius:var(--radius-sm);
  background:var(--color-ink);
  color:var(--color-paper);
  -webkit-overflow-scrolling:touch;
}
pre code{overflow-wrap:normal}
table{border-collapse:collapse}
summary{cursor:pointer}
.no-break{white-space:nowrap}
.mono,.num{font-family:var(--font-mono);font-variant-numeric:tabular-nums}
.highlight,.hl{color:var(--color-brand)}
.wrap,.container{
  width:100%;
  max-width:var(--content-width);
  margin-inline:auto;
  padding-inline:var(--gutter);
}
.reading-wrap{
  width:100%;
  max-width:calc(var(--reading-width) + var(--gutter) * 2);
  margin-inline:auto;
  padding-inline:var(--gutter);
}
.section{
  padding-top:var(--section-space);
  padding-bottom:var(--section-space);
}
.section-head{max-width:760px;margin-bottom:42px}
.section-head p{color:var(--color-muted);font-size:18px}
.panel,.card{
  min-width:0;
  border:1px solid var(--color-line);
  border-radius:var(--radius-md);
  background:var(--color-surface);
  box-shadow:var(--shadow-card);
}
.panel-strong{background:var(--color-surface-strong)}
.paper{background:var(--color-paper)}
.badge,.chip{
  display:inline-flex;
  min-height:28px;
  max-width:100%;
  align-items:center;
  gap:7px;
  padding:4px 11px;
  overflow:hidden;
  border:1px solid var(--color-line);
  border-radius:var(--radius-pill);
  background:var(--color-paper);
  color:var(--color-muted);
  font-size:13px;
  line-height:1.35;
}
.badge-dot{
  width:7px;
  height:7px;
  flex:0 0 auto;
  border-radius:50%;
  background:var(--color-success);
  box-shadow:0 0 0 3px var(--color-success-soft);
}
.badge-brand{border-color:var(--color-brand-mid);background:var(--color-brand-soft);color:var(--color-brand-deep)}
.btn{
  display:inline-flex;
  min-width:24px;
  min-height:44px;
  align-items:center;
  justify-content:center;
  gap:8px;
  padding:11px 24px;
  border:1px solid transparent;
  border-radius:var(--radius-sm);
  font-weight:700;
  line-height:1.25;
  text-align:center;
  transition:transform var(--duration-fast) ease,background var(--duration-fast) ease,border-color var(--duration-fast) ease,color var(--duration-fast) ease;
}
.btn:hover{transform:translateY(-2px)}
.btn-primary{background:var(--color-brand);color:var(--color-paper);box-shadow:var(--shadow-button)}
.btn-primary:hover{background:var(--color-brand-deep);color:var(--color-paper)}
.btn-secondary{border-color:var(--color-line);background:var(--color-paper);color:var(--color-ink)}
.btn-secondary:hover{border-color:var(--color-brand);color:var(--color-brand)}
.btn-quiet{border-color:var(--color-brand);background:transparent;color:var(--color-brand)}
.btn[aria-disabled="true"],.btn:disabled{cursor:not-allowed;opacity:.55;transform:none}
.icon-inline{width:18px;height:18px;flex:0 0 auto}
.site-header{
  position:sticky;
  top:0;
  z-index:60;
  border-bottom:1px solid var(--color-line);
  background:var(--color-surface);
}
.header-bar{
  display:flex;
  height:var(--header-height);
  align-items:center;
  gap:24px;
}
.brand{
  display:flex;
  flex:0 0 auto;
  align-items:center;
  gap:10px;
  color:var(--color-ink);
}
.brand-logo{width:32px;height:32px;flex:0 0 auto}
.brand-copy{display:flex;align-items:baseline;gap:7px;white-space:nowrap}
.brand-name{font-family:var(--font-display);font-size:19px;font-weight:850}
.brand-local{color:var(--color-muted);font-size:13px;font-weight:550}
.desktop-nav{display:flex;height:100%;min-width:0;flex:1;align-items:stretch}
.desktop-nav a{
  position:relative;
  display:flex;
  min-height:44px;
  align-items:center;
  padding-inline:11px;
  color:var(--color-muted);
  font-size:14px;
  white-space:nowrap;
}
.desktop-nav a:hover{color:var(--color-ink)}
.desktop-nav a.is-active{color:var(--color-brand);font-weight:700}
.desktop-nav a.is-active::after{
  position:absolute;
  right:9px;
  bottom:0;
  left:9px;
  height:3px;
  border-radius:3px 3px 0 0;
  background:var(--color-brand);
  content:"";
}
.header-tools{
  display:flex;
  flex:0 0 auto;
  align-items:center;
  gap:9px;
}
.language-box{position:relative}
.language-button,.menu-button{
  min-width:44px;
  min-height:44px;
  border:0;
  border-radius:var(--radius-sm);
  background:transparent;
  color:var(--color-muted);
}
.language-button{padding-inline:10px;font-size:13px;white-space:nowrap}
.language-button:hover,.menu-button:hover{background:var(--color-brand-soft)}
.language-menu{
  position:absolute;
  top:calc(100% + 8px);
  right:0;
  z-index:75;
  width:154px;
  padding:6px;
  border:1px solid var(--color-line);
  border-radius:var(--radius-sm);
  background:var(--color-paper);
  box-shadow:var(--shadow-card);
}
.language-menu[hidden]{display:none}
.language-menu a{
  display:flex;
  min-height:40px;
  align-items:center;
  padding:7px 9px;
  border-radius:var(--radius-xs);
  color:var(--color-ink);
  font-size:13px;
}
.language-menu a:hover,.language-menu a[aria-current="true"]{background:var(--color-brand-soft);color:var(--color-brand)}
.login-button{
  display:inline-flex;
  min-height:40px;
  align-items:center;
  padding:8px 18px;
  border-radius:var(--radius-sm);
  background:var(--color-brand);
  color:var(--color-paper);
  font-size:14px;
  font-weight:700;
  box-shadow:var(--shadow-button);
}
.login-button:hover{background:var(--color-brand-deep);color:var(--color-paper)}
.menu-button{display:none;padding:10px}
.menu-button svg{width:22px;height:22px}
.mobile-nav{
  position:absolute;
  top:var(--header-height);
  right:0;
  left:0;
  z-index:72;
  display:none;
  max-height:calc(100dvh - var(--header-height));
  overflow-y:auto;
  overscroll-behavior:contain;
  border-bottom:1px solid var(--color-line);
  background:var(--color-paper);
  box-shadow:var(--shadow-card);
}
.mobile-nav.is-open{display:block}
.mobile-nav-inner{padding-top:10px;padding-bottom:16px}
.mobile-nav a{
  display:flex;
  width:100%;
  min-height:46px;
  align-items:center;
  padding:10px 12px;
  border-radius:var(--radius-sm);
  color:var(--color-ink);
}
.mobile-nav a:hover,.mobile-nav a.is-active{background:var(--color-brand-soft);color:var(--color-brand)}
.mobile-language{margin-top:8px;padding-top:8px;border-top:1px solid var(--color-line)}
.mobile-language-label{padding:8px 12px;color:var(--color-muted);font-size:12px}
.nav-veil{
  position:fixed;
  inset:var(--header-height) 0 0;
  z-index:55;
  border:0;
  background:rgba(18,40,60,.18);
}
.nav-veil[hidden]{display:none}
.site-footer{
  margin-top:var(--section-space);
  border-top:1px solid var(--color-line);
  background:var(--color-surface);
}
.footer-grid{
  display:grid;
  grid-template-columns:1.4fr 1fr 1.15fr .8fr;
  gap:34px;
  padding-top:54px;
  padding-bottom:38px;
}
.footer-brand p{max-width:340px;color:var(--color-muted)}
.footer-title{margin-bottom:13px;font-size:14px;font-weight:800}
.footer-links{display:grid;gap:7px}
.footer-links a{
  display:inline-flex;
  min-height:28px;
  align-items:center;
  color:var(--color-muted);
  font-size:14px;
}
.footer-links a:hover{color:var(--color-brand)}
.footer-bottom{
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap:16px;
  padding-top:20px;
  padding-bottom:24px;
  border-top:1px solid var(--color-line);
  color:var(--color-muted);
  font-size:13px;
}
.footer-legal{display:flex;flex-wrap:wrap;gap:16px}
.reveal{transition:opacity .55s ease,transform .55s ease}
.reveal.pending{opacity:0;transform:translateY(16px)}
.reveal.shown{opacity:1;transform:none}
.prose{color:var(--color-ink)}
.prose p,.prose li{color:var(--color-muted)}
.prose h2,.prose h3{scroll-margin-top:var(--toc-offset)}
.prose a{text-decoration:underline;text-decoration-thickness:1px;text-underline-offset:3px}
.prose img{border-radius:var(--radius-sm)}
.prose hr{margin:40px 0;border:0;border-top:1px solid var(--color-line)}
:where(a,button,input,select,textarea,summary,[role="tab"]):focus-visible{
  outline:2px solid var(--color-brand);
  outline-offset:3px;
}
@media (max-width:1080px){
  .desktop-nav{display:none}
  .header-tools{margin-left:auto}
  .menu-button{display:grid;place-items:center}
  .footer-grid{grid-template-columns:repeat(2,minmax(0,1fr))}
}
@media (max-width:768px){
  :root{--gutter:20px;--section-space:64px}
  h1{font-size:clamp(32px,10vw,40px);line-height:1.12;letter-spacing:-.01em}
  h2{font-size:clamp(28px,8vw,36px)}
  .brand-local,.language-box{display:none}
  .header-bar{gap:10px}
  .login-button{padding-inline:13px}
  .section-head p{font-size:16px}
  .footer-bottom{align-items:flex-start;flex-direction:column}
}
@media (max-width:640px){
  :root{--gutter:16px}
  body{font-size:15px}
  .wrap,.container,.reading-wrap{padding-inline:var(--gutter)}
  .tilt,.app-window{transform:none!important}
  .footer-grid{grid-template-columns:1fr}
  .btn{width:100%}
}
@media (max-width:360px){
  .brand-logo{width:29px;height:29px}
  .brand-name{font-size:17px}
  .login-button{padding-inline:10px}
}
@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  *,*::before,*::after{scroll-behavior:auto!important;animation:none!important;transition:none!important}
  .reveal,.reveal.pending{opacity:1!important;transform:none!important}
}