:root{
  --color-canvas:#FFFFFF;
  --color-panel:#F8FAFA;
  --color-panel-strong:#F1F4F5;
  --color-line:#E3E8EA;
  --color-accent:#00A88E;
  --color-accent-deep:#0B7C97;
  --color-accent-blue:#1287C9;
  --color-accent-soft:#E4F6F1;
  --color-ink:#111518;
  --color-muted:#5C6670;
  --color-success:#4CAE4F;
  --color-warning:#F2B01E;
  --color-danger:#EE6A4D;
  --color-flag-red:#D8433B;
  --color-flag-blue:#2E4C8F;
  --color-overlay:rgba(17,21,24,.38);
  --color-shadow:rgba(17,21,24,.16);
  --color-accent-shadow:rgba(0,168,142,.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:8px;
  --radius-sm:12px;
  --radius-card:16px;
  --radius-panel:24px;
  --radius-pill:999px;
  --shadow-card:0 12px 28px -14px var(--color-shadow);
  --shadow-raised:0 24px 56px -28px var(--color-shadow);
  --shadow-button:0 10px 22px -10px var(--color-accent-shadow);
  --wrap:1180px;
  --wrap-wide:1400px;
  --reading:780px;
  --gutter:clamp(16px,3vw,32px);
  --header-height:68px;
  --section-space:clamp(64px,9vw,120px);
  --toc-top:76px;
  --ease:cubic-bezier(.2,.7,.2,1);
}
*,*::before,*::after{box-sizing:border-box}
html{scroll-behavior:smooth;background:var(--color-canvas);color:var(--color-ink);font-family:var(--font-body);-webkit-text-size-adjust:100%}
html.nav-open{overflow:hidden}
body{margin:0;min-width:320px;background:var(--color-canvas);color:var(--color-ink);font-family:var(--font-body);line-height:1.65;-webkit-font-smoothing:antialiased;overflow-wrap:break-word}
main,section,article,aside,header,footer,nav,div{min-width:0}
img,svg,video{display:block;max-width:100%}
img{height:auto}
button,input,select,textarea{font:inherit;color:inherit}
button{cursor:pointer}
a{color:var(--color-accent-deep);text-decoration-thickness:.08em;text-underline-offset:.18em}
a:hover{color:var(--color-accent)}
ul,ol{padding-left:1.25em}
code,kbd,samp,pre{font-family:var(--font-mono)}
code{overflow-wrap:anywhere}
pre{max-width:100%;padding:20px;overflow:auto;border:1px solid var(--color-line);border-radius:var(--radius-sm);background:var(--color-panel);font-size:.88rem;line-height:1.7}
pre code{overflow-wrap:normal}
table{border-collapse:collapse}
summary{cursor:pointer}
::selection{background:var(--color-accent-soft);color:var(--color-ink)}
:focus-visible{outline:3px solid var(--color-accent);outline-offset:3px}
.wrap{width:100%;max-width:var(--wrap);margin-inline:auto;padding-inline:var(--gutter)}
.wrap-wide{width:100%;max-width:var(--wrap-wide);margin-inline:auto;padding-inline:var(--gutter)}
.reading{width:100%;max-width:var(--reading);margin-inline:auto;padding-inline:var(--gutter)}
.section{padding-top:var(--section-space);padding-bottom:var(--section-space)}
.section-compact{padding-top:clamp(42px,6vw,72px);padding-bottom:clamp(42px,6vw,72px)}
.stack>*{margin-block:0}
.stack>*+*{margin-top:1rem}
.cluster{display:flex;flex-wrap:wrap;align-items:center;gap:12px}
.grid{display:grid;gap:24px}
.grid>*{min-width:0}
.grid-2{grid-template-columns:repeat(2,minmax(0,1fr))}
.grid-3{grid-template-columns:repeat(3,minmax(0,1fr))}
.eyebrow{font-family:var(--font-mono);font-size:.76rem;letter-spacing:.14em;text-transform:uppercase;color:var(--color-muted)}
h1,h2,h3,h4{margin:0 0 .65em;font-family:var(--font-display);line-height:1.16;color:var(--color-ink);text-wrap:balance}
h1{font-size:clamp(52px,6vw,72px);font-weight:800;letter-spacing:-.02em}
h2{font-size:clamp(34px,4.5vw,54px);font-weight:800;letter-spacing:-.018em}
h3{font-size:clamp(22px,2.3vw,30px);font-weight:750}
h4{font-size:1.12rem}
p{margin:0 0 1.1em;color:var(--color-muted)}
.lead{font-size:clamp(18px,2vw,22px);line-height:1.65}
.text-ink{color:var(--color-ink)}
.text-muted{color:var(--color-muted)}
.mono{font-family:var(--font-mono)}
.nowrap-keyword{white-space:nowrap}
.gradient-text{background:linear-gradient(92deg,var(--color-accent),var(--color-accent-blue));background-clip:text;-webkit-background-clip:text;color:transparent;-webkit-text-fill-color:transparent}
.panel,.card{border:1px solid var(--color-line);background:var(--color-canvas);border-radius:var(--radius-panel)}
.panel{padding:clamp(22px,4vw,40px);box-shadow:var(--shadow-card)}
.card{padding:24px;border-radius:var(--radius-card)}
.tilt{transform:rotate(-.35deg)}
.badge,.chip{display:inline-flex;align-items:center;gap:8px;max-width:100%;min-height:30px;padding:4px 14px;border:1px solid var(--color-line);border-radius:var(--radius-pill);background:var(--color-canvas);color:var(--color-muted);font-size:.82rem;line-height:1.4}
.badge-dot,.status-dot{width:7px;height:7px;flex:0 0 auto;border-radius:50%;background:var(--color-accent)}
.badge-success{border-color:var(--color-success);color:var(--color-ink)}
.badge-warning{border-color:var(--color-warning);color:var(--color-ink)}
.badge-danger{border-color:var(--color-danger);color:var(--color-ink)}
.btn{display:inline-flex;min-height:50px;align-items:center;justify-content:center;gap:9px;padding:10px 28px;border:1.5px solid transparent;border-radius:var(--radius-pill);font-weight:750;line-height:1.2;text-decoration:none;transition:transform .16s var(--ease),box-shadow .16s var(--ease),background .16s var(--ease),border-color .16s var(--ease)}
.btn:hover{transform:translateY(-2px);text-decoration:none}
.btn-primary{background:var(--color-accent);color:var(--color-canvas);box-shadow:var(--shadow-button)}
.btn-primary:hover{background:var(--color-accent-deep);color:var(--color-canvas)}
.btn-secondary{border-color:var(--color-line);background:var(--color-canvas);color:var(--color-ink)}
.btn-secondary:hover{border-color:var(--color-muted);color:var(--color-ink)}
.btn-dark{background:var(--color-ink);color:var(--color-canvas)}
.btn-dark:hover{color:var(--color-canvas);box-shadow:var(--shadow-card)}
.btn-small{min-height:42px;padding:8px 20px;font-size:.9rem}
.btn[aria-disabled="true"],.btn:disabled{opacity:.5;pointer-events:none}
.site-head{position:relative;z-index:100;height:var(--header-height);background:var(--color-canvas)}
.head-inner{width:100%;max-width:var(--wrap-wide);height:100%;margin-inline:auto;padding-inline:var(--gutter);display:flex;align-items:center;gap:24px}
.brand{display:flex;align-items:center;gap:10px;flex:0 0 auto;color:var(--color-ink);text-decoration:none}
.brand:hover{color:var(--color-ink)}
.brand-logo{width:34px;height:34px;flex:0 0 auto}
.brand-word{font-family:var(--font-display);font-size:19px;font-weight:800;letter-spacing:-.02em}
.brand-local{font-size:13px;font-weight:550;color:var(--color-muted)}
.main-nav{display:flex;align-items:center;gap:2px;margin-inline:auto}
.main-nav a{display:inline-flex;align-items:center;min-height:38px;padding:7px 13px;border-radius:var(--radius-pill);color:var(--color-muted);font-size:14px;text-decoration:none}
.main-nav a:hover{background:var(--color-panel-strong);color:var(--color-ink)}
.main-nav a.is-active{background:var(--color-accent-soft);color:var(--color-accent-deep);font-weight:700}
.head-tools{display:flex;align-items:center;gap:10px;flex:0 0 auto}
.login-link{display:inline-flex;min-height:42px;align-items:center;padding:8px 20px;border:1.5px solid var(--color-ink);border-radius:var(--radius-pill);color:var(--color-ink);font-size:14px;font-weight:700;text-decoration:none}
.login-link:hover{background:var(--color-ink);color:var(--color-canvas)}
.lang-menu{position:relative}
.lang-toggle,.menu-toggle{min-width:44px;min-height:44px;border:0;background:transparent;border-radius:var(--radius-pill)}
.lang-toggle{padding:7px 8px;color:var(--color-muted);font-size:13px}
.lang-toggle:hover,.menu-toggle:hover{background:var(--color-panel-strong);color:var(--color-ink)}
.lang-popover{position:absolute;top:calc(100% + 8px);right:0;width:170px;padding:8px;border:1px solid var(--color-line);border-radius:var(--radius-sm);background:var(--color-canvas);box-shadow:var(--shadow-raised)}
.lang-popover[hidden]{display:none}
.lang-popover a{display:block;min-height:42px;padding:9px 12px;border-radius:var(--radius-xs);color:var(--color-ink);text-decoration:none}
.lang-popover a:hover,.lang-popover a[aria-current="true"]{background:var(--color-accent-soft);color:var(--color-accent-deep)}
.menu-toggle{display:none;align-items:center;justify-content:center;padding:0}
.menu-toggle-lines,.menu-toggle-lines::before,.menu-toggle-lines::after{display:block;width:20px;height:2px;background:var(--color-ink);border-radius:var(--radius-pill)}
.menu-toggle-lines{position:relative}
.menu-toggle-lines::before,.menu-toggle-lines::after{content:"";position:absolute;left:0}
.menu-toggle-lines::before{top:-6px}
.menu-toggle-lines::after{top:6px}
.mobile-nav{display:none}
.nav-veil{display:none}
.site-footer{border-top:1px solid var(--color-line);background:var(--color-panel)}
.footer-main{display:grid;grid-template-columns:1.35fr 1fr 1.2fr;gap:48px;padding-top:64px;padding-bottom:46px}
.footer-brand p{max-width:420px;margin-top:18px}
.footer-title{margin-bottom:16px;font-size:.82rem;font-family:var(--font-mono);letter-spacing:.12em;color:var(--color-muted)}
.footer-links{display:grid;gap:9px;padding:0;margin:0;list-style:none}
.footer-links a{color:var(--color-muted);text-decoration:none}
.footer-links a:hover{color:var(--color-accent-deep)}
.footer-keywords{display:flex;flex-wrap:wrap;gap:8px}
.footer-keywords a{padding:6px 10px;border:1px solid var(--color-line);border-radius:var(--radius-pill);background:var(--color-canvas);color:var(--color-muted);font-size:.82rem;text-decoration:none}
.footer-bottom{display:flex;flex-wrap:wrap;justify-content:space-between;align-items:center;gap:16px;padding-top:22px;padding-bottom:28px;border-top:1px solid var(--color-line);font-size:.85rem;color:var(--color-muted)}
.footer-languages{display:flex;flex-wrap:wrap;gap:12px}
.footer-languages a{color:var(--color-muted)}
.reveal{transition:opacity .62s var(--ease),transform .62s var(--ease)}
.reveal.pending{opacity:0;transform:translateY(16px)}
.reveal.shown{opacity:1;transform:none}
body:has(.toc-tabs) section[id]{scroll-margin-top:calc(var(--toc-top) + 74px)}
@media(max-width:1080px){
  .main-nav{display:none}
  .head-tools{margin-left:auto}
  .menu-toggle{display:inline-flex}
  .mobile-nav{position:fixed;z-index:104;top:var(--header-height);left:0;right:0;display:none;max-height:calc(100dvh - var(--header-height));padding:12px var(--gutter) 24px;overflow-y:auto;overscroll-behavior:contain;border-top:1px solid var(--color-line);background:var(--color-canvas)}
  .mobile-nav.is-open{display:block}
  .mobile-nav ul{margin:0;padding:0;list-style:none}
  .mobile-nav a{display:flex;width:100%;min-height:48px;align-items:center;padding:11px 14px;border-radius:var(--radius-sm);color:var(--color-ink);text-decoration:none}
  .mobile-nav a:hover,.mobile-nav a.is-active{background:var(--color-accent-soft);color:var(--color-accent-deep)}
  .mobile-language-list{margin-top:10px!important;padding-top:10px!important;border-top:1px solid var(--color-line)}
  .nav-veil{position:fixed;z-index:99;inset:var(--header-height) 0 0;background:var(--color-overlay)}
  .nav-veil.is-open{display:block}
  .lang-menu{display:none}
}
@media(max-width:768px){
  h1{font-size:clamp(32px,10vw,40px);line-height:1.14}
  h2{font-size:clamp(29px,8vw,40px)}
  .grid-3,.grid-2{grid-template-columns:1fr}
  .footer-main{grid-template-columns:1fr;gap:34px}
  .brand-local{display:none}
}
@media(max-width:640px){
  :root{--gutter:16px}
  .tilt{transform:none}
  .head-inner{gap:8px}
  .brand-logo{width:32px;height:32px}
  .brand-word{font-size:17px}
  .login-link{min-height:40px;padding-inline:14px}
  .btn{width:100%}
  .cluster.actions{display:grid;grid-template-columns:1fr}
  .footer-bottom{align-items:flex-start;flex-direction:column}
}
@media(prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  .reveal,.reveal.pending,.reveal.shown{opacity:1;transform:none;transition:none}
  .btn,.btn:hover{transform:none;transition:none}
}