:root{
  --bg:#0F1114;
  --bg-panel:#161A1F;
  --bg-panel-2:#1D232B;
  --border:#2A313C;
  --accent:#66BCFF;
  --accent-dark:#2277C9;
  --text:#E8EDF4;
  --text-muted:#9AA6B5;
  --success:#55C98A;
  --warn:#F5C86B;
  --error:#F2635C;
  --accent-glow-strong:rgba(102,188,255,.38);
  --accent-glow:rgba(102,188,255,.22);
  --accent-glow-soft:rgba(102,188,255,.08);
  --grid-dot:rgba(154,166,181,.13);
  --shadow-deep:rgba(0,0,0,.50);
  --shadow-mid:rgba(0,0,0,.28);
  --button-fg:#0C1218;
  --overlay:rgba(15,17,20,.82);
  --flag-red:#C8515A;
  --flag-blue:#3F5FA8;
  --flag-white:#E8EDF4;
  --flag-green:#55C98A;
  --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,'Liberation Mono',monospace;
  --radius-sm:6px;
  --radius-md:10px;
  --radius-lg:14px;
  --radius-pill:999px;
  --header-height:64px;
  --gutter:clamp(16px,3vw,32px);
  --content-width:1240px;
  --reading-width:820px;
  --section-space:clamp(64px,9vw,112px);
  --focus-width:2px;
  --toc-offset:84px;
  --ease:cubic-bezier(.2,.75,.25,1);
}

*,*::before,*::after{box-sizing:border-box}
html{
  color-scheme:dark;
  scroll-behavior:smooth;
  scroll-padding-top:calc(var(--header-height) + 16px);
  background:var(--bg);
}
html.nav-open{overflow:hidden}
body{
  margin:0;
  min-width:320px;
  overflow-x:clip;
  color:var(--text);
  background:var(--bg);
  font-family:var(--font-body);
  font-size:16px;
  line-height:1.65;
  text-rendering:optimizeLegibility;
  -webkit-font-smoothing:antialiased;
}
body,button,input,select,textarea{font:inherit}
h1,h2,h3,h4,p,ul,ol,dl,dd,figure,blockquote{margin:0}
ul,ol{padding:0}
ul[role="list"],.plain-list{list-style:none}
img,svg,video,canvas{display:block;max-width:100%}
img{height:auto}
button,input,select,textarea{color:inherit}
button{cursor:pointer}
a{color:inherit;text-decoration:none}
a:not([class]){color:var(--accent);text-underline-offset:.18em}
strong{color:var(--text);font-weight:650}
code,kbd,pre{font-family:var(--font-mono)}
code{
  overflow-wrap:anywhere;
  color:var(--accent);
  background:var(--bg-panel-2);
  border-radius:var(--radius-sm);
  padding:.12em .38em;
}
pre{
  max-width:100%;
  overflow-x:auto;
  margin:24px 0;
  padding:20px;
  color:var(--text);
  background:var(--bg-panel);
  border:1px solid var(--border);
  border-radius:var(--radius-md);
  -webkit-overflow-scrolling:touch;
}
pre code{padding:0;color:inherit;background:transparent}
hr{border:0;border-top:1px solid var(--border)}
::selection{color:var(--button-fg);background:var(--accent)}
:where(a,button,input,select,textarea,summary,[role="tab"]):focus-visible{
  outline:var(--focus-width) solid var(--accent);
  outline-offset:3px;
}
.no-break{white-space:nowrap}
.muted{color:var(--text-muted)}
.mono{font-family:var(--font-mono)}
.wrap,.container{
  width:100%;
  max-width:var(--content-width);
  margin-inline:auto;
  padding-inline:var(--gutter);
}
.reading{
  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-compact{
  padding-top:clamp(42px,6vw,72px);
  padding-bottom:clamp(42px,6vw,72px);
  overflow-x:clip;
}
.panel,.card{
  min-width:0;
  background:var(--bg-panel);
  border:1px solid var(--border);
  border-radius:var(--radius-lg);
}
.panel-raised,.card-raised{
  background:var(--bg-panel-2);
  box-shadow:0 20px 52px var(--shadow-mid);
}
.eyebrow{
  display:inline-flex;
  align-items:center;
  gap:8px;
  max-width:100%;
  margin-bottom:18px;
  padding:5px 13px;
  color:var(--text-muted);
  background:var(--bg-panel);
  border:1px solid var(--border);
  border-radius:var(--radius-pill);
  font-size:13px;
}
.eyebrow-dot,.status-dot{
  width:7px;
  height:7px;
  flex:0 0 auto;
  border-radius:50%;
  background:var(--accent);
  box-shadow:0 0 9px var(--accent-glow-strong);
}
h1,.display-title{
  max-width:100%;
  font-family:var(--font-display);
  font-size:clamp(52px,5.4vw,72px);
  font-weight:800;
  line-height:1.1;
  letter-spacing:-.015em;
  text-wrap:balance;
}
h2{
  font-family:var(--font-display);
  font-size:clamp(32px,4vw,48px);
  font-weight:760;
  line-height:1.16;
  letter-spacing:-.012em;
  text-wrap:balance;
}
h3{
  font-family:var(--font-display);
  font-size:clamp(21px,2.4vw,28px);
  line-height:1.3;
}
.section-head{max-width:760px;margin-bottom:40px}
.section-head p{margin-top:14px;color:var(--text-muted);font-size:clamp(16px,1.6vw,19px)}
.accent-text{color:var(--accent)}
.warn-text{color:var(--warn)}
.btn{
  display:inline-flex;
  min-width:24px;
  min-height:44px;
  align-items:center;
  justify-content:center;
  gap:9px;
  border:1px solid transparent;
  border-radius:var(--radius-md);
  padding:11px 24px;
  font-family:var(--font-display);
  font-weight:700;
  line-height:1.25;
  text-align:center;
  transition:transform .18s var(--ease),background-color .18s var(--ease),border-color .18s var(--ease),box-shadow .18s var(--ease);
}
.btn:hover{transform:translateY(-1px)}
.btn-primary{
  color:var(--button-fg);
  background:var(--accent);
  box-shadow:0 0 0 1px var(--accent-glow),0 8px 26px var(--accent-glow-strong);
}
.btn-primary:hover{box-shadow:0 0 0 1px var(--accent-glow),0 12px 32px var(--accent-glow-strong)}
.btn-secondary{color:var(--text);background:transparent;border-color:var(--border)}
.btn-secondary:hover{background:var(--bg-panel);border-color:var(--accent-dark)}
.btn-quiet{min-height:36px;padding:7px 15px;color:var(--text-muted);background:var(--bg-panel);border-color:var(--border);font-size:13px}
.btn[aria-disabled="true"],.btn:disabled{cursor:not-allowed;opacity:.55;transform:none}
.button-row{display:flex;flex-wrap:wrap;gap:14px;align-items:center}
.badge,.tag,.fact-chip{
  display:inline-flex;
  max-width:100%;
  min-height:28px;
  align-items:center;
  gap:7px;
  padding:4px 11px;
  overflow:hidden;
  border:1px solid var(--border);
  border-radius:var(--radius-pill);
  color:var(--text-muted);
  background:var(--bg-panel);
  font-size:12.5px;
}
.badge-accent{color:var(--accent);border-color:var(--accent-dark);background:var(--accent-glow-soft)}
.badge-warn{color:var(--warn)}
.fact-list{display:flex;flex-wrap:wrap;gap:10px;list-style:none}
.fact-chip svg{width:12px;height:12px;flex:0 0 auto;color:var(--success)}
.prose{min-width:0;color:var(--text-muted)}
.prose>*+*{margin-top:18px}
.prose h2{margin-top:56px;color:var(--text)}
.prose h3{margin-top:36px;color:var(--text)}
.prose ul,.prose ol{padding-left:1.35em}
.prose li+li{margin-top:8px}
.prose img{border-radius:var(--radius-md)}
.reveal{transition:opacity .65s var(--ease),transform .65s var(--ease)}
.reveal.pending{opacity:0;transform:translateY(16px)}
.reveal.shown{opacity:1;transform:none}

.site-head{
  position:relative;
  z-index:80;
  border-bottom:1px solid var(--border);
  background:var(--bg);
}
.head-row{
  min-height:var(--header-height);
  display:flex;
  align-items:center;
  gap:28px;
}
.brand{display:flex;flex:0 0 auto;align-items:center;gap:10px;min-height:44px}
.brand-logo{width:30px;height:30px;flex:0 0 auto}
.brand-name{font-family:var(--font-display);font-size:19px;font-weight:800;letter-spacing:.01em}
.brand-local{color:var(--text-muted);font-size:14px;font-weight:550}
.main-nav{min-width:0;flex:1}
.main-nav ul{display:flex;align-items:center;list-style:none}
.main-nav li{display:flex;align-items:center;white-space:nowrap}
.main-nav li+li::before{content:"·";margin:0 13px;color:var(--border);font-weight:800}
.main-nav a{
  display:inline-flex;
  min-height:32px;
  align-items:center;
  color:var(--text-muted);
  font-size:13.5px;
  transition:color .16s ease;
}
.main-nav a:hover{color:var(--text)}
.main-nav a.is-active{color:var(--accent);font-weight:650}
.head-tools{display:flex;flex:0 0 auto;align-items:center;gap:10px}
.language-menu{position:relative}
.lang-trigger{
  min-width:44px;
  min-height:44px;
  padding:6px 8px;
  color:var(--text-muted);
  background:transparent;
  border:0;
  border-radius:var(--radius-sm);
  font-size:13px;
}
.lang-trigger:hover{color:var(--text)}
.lang-popover{
  position:absolute;
  top:calc(100% + 8px);
  right:0;
  z-index:95;
  width:156px;
  padding:7px;
  list-style:none;
  background:var(--bg-panel-2);
  border:1px solid var(--border);
  border-radius:var(--radius-md);
  box-shadow:0 16px 42px var(--shadow-deep);
}
.lang-popover[hidden]{display:none}
.lang-popover a{display:flex;min-height:40px;align-items:center;padding:8px 10px;border-radius:var(--radius-sm);color:var(--text-muted);font-size:13px}
.lang-popover a:hover,.lang-popover a[aria-current="true"]{color:var(--text);background:var(--bg-panel)}
.login-link{
  display:inline-flex;
  min-height:38px;
  align-items:center;
  justify-content:center;
  padding:7px 17px;
  color:var(--text);
  background:var(--bg-panel);
  border:1px solid var(--border);
  border-radius:var(--radius-sm);
  font-size:13.5px;
  font-weight:650;
}
.login-link:hover{background:var(--bg-panel-2);border-color:var(--accent-dark)}
.menu-toggle{
  display:none;
  min-width:44px;
  min-height:44px;
  place-items:center;
  padding:0;
  color:var(--text);
  background:var(--bg-panel);
  border:1px solid var(--border);
  border-radius:var(--radius-sm);
}
.menu-toggle svg{width:20px;height:20px}
.mobile-nav{
  display:none;
  position:absolute;
  top:100%;
  left:0;
  right:0;
  z-index:92;
  max-height:calc(100dvh - var(--header-height));
  overflow-y:auto;
  overscroll-behavior:contain;
  padding:10px var(--gutter) 22px;
  background:var(--bg-panel);
  border-top:1px solid var(--border);
  border-bottom:1px solid var(--border);
}
.mobile-nav.is-open{display:block}
.mobile-nav ul{list-style:none}
.mobile-nav a{
  display:flex;
  width:100%;
  min-height:48px;
  align-items:center;
  padding:11px 8px;
  color:var(--text-muted);
  border-bottom:1px solid var(--border);
}
.mobile-nav a.is-active{color:var(--accent)}
.mobile-nav .mobile-languages{margin-top:12px}
.mobile-nav .mobile-languages a{min-height:44px}
.nav-veil{
  display:none;
  position:fixed;
  inset:var(--header-height) 0 0;
  z-index:70;
  background:var(--overlay);
}
.nav-veil.is-open{display:block}

.site-footer{
  overflow-x:clip;
  border-top:1px solid var(--border);
  background:var(--bg-panel);
}
.footer-grid{
  display:grid;
  grid-template-columns:1.3fr 1fr 1.15fr;
  gap:56px;
  padding-top:60px;
  padding-bottom:48px;
}
.footer-brand p{max-width:390px;margin-top:16px;color:var(--text-muted);font-size:14px}
.footer-title{margin-bottom:16px;color:var(--text);font-family:var(--font-mono);font-size:11px;letter-spacing:.14em;text-transform:uppercase}
.footer-links{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:8px 18px;list-style:none}
.footer-links a,.footer-hot a{display:inline-flex;min-height:30px;align-items:center;color:var(--text-muted);font-size:13.5px}
.footer-links a:hover,.footer-hot a:hover{color:var(--accent)}
.footer-hot{display:flex;flex-wrap:wrap;gap:7px 14px;list-style:none}
.footer-languages{display:flex;flex-wrap:wrap;gap:8px 16px;margin-top:24px;list-style:none}
.footer-languages a{display:inline-flex;min-height:28px;align-items:center;color:var(--text-muted);font-size:12.5px}
.footer-bottom{
  display:flex;
  justify-content:space-between;
  gap:20px;
  padding-top:20px;
  padding-bottom:24px;
  color:var(--text-muted);
  border-top:1px solid var(--border);
  font-size:12.5px;
}
.footer-legal{display:flex;flex-wrap:wrap;gap:18px}

@media (max-width:1100px){
  .main-nav{display:none}
  .head-tools{margin-left:auto}
  .menu-toggle{display:grid}
}
@media (max-width:768px){
  h1,.display-title{font-size:clamp(28px,9.5vw,40px);line-height:1.12;letter-spacing:-.01em}
  h2{font-size:clamp(27px,8vw,36px)}
  .section{padding-top:64px;padding-bottom:64px}
  .footer-grid{grid-template-columns:1fr 1fr;gap:38px}
  .footer-brand{grid-column:1/-1}
}
@media (max-width:640px){
  :root{--gutter:16px}
  .tilt,.tilted,[class*="tilt-"]{transform:none}
  .brand-local,.desktop-language{display:none}
  .head-row{gap:10px}
  .head-tools{margin-left:auto;gap:7px}
  .login-link{padding-inline:13px}
  .button-row .btn{width:100%}
  .footer-grid{grid-template-columns:1fr}
  .footer-brand{grid-column:auto}
  .footer-bottom{flex-direction:column}
}
@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}
}