:root{
  --color-bg:#F8FAFA;
  --color-panel:#FFFFFF;
  --color-panel-soft:#EDF3F1;
  --color-border:#DAE4E1;
  --color-accent:#24BFA3;
  --color-accent-soft:#6FD9C6;
  --color-accent-dark:#128870;
  --color-on-accent:#05231D;
  --color-text:#141F1D;
  --color-muted:#5B6A66;
  --color-success:#2F9E5B;
  --color-warning:#D89A26;
  --color-error:#D64949;
  --color-ink:#0E1A21;
  --color-ink-panel:#14232C;
  --color-ink-line:#22343D;
  --color-ring:#2C4149;
  --color-ink-text:#E8F0EE;
  --color-ink-muted:#8CA0A5;
  --color-grid-dot:rgba(224,240,236,.06);
  --color-glow:rgba(36,191,163,.34);
  --color-glow-strong:rgba(36,191,163,.5);
  --color-shadow:rgba(4,10,13,.45);
  --color-overlay:rgba(4,10,13,.72);
  --color-focus:#24BFA3;
  --color-logo:#FFFFFF;
  --color-flag-red:#C8393E;
  --color-flag-blue:#31548F;
  --color-flag-white:#F3F6F5;
  --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-lg:22px;
  --radius-pill:999px;
  --shadow-card:0 18px 46px rgba(14,26,33,.09);
  --shadow-ink:0 16px 40px var(--color-shadow);
  --header-height:68px;
  --gutter:clamp(16px,4vw,44px);
  --content-width:1180px;
  --reading-width:800px;
  --section-space:clamp(64px,9vw,112px);
  --focus-ring:2px solid var(--color-focus);
  --transition-fast:160ms ease;
}
*,*::before,*::after{box-sizing:border-box}
html{margin:0;scroll-behavior: smooth;scroll-padding-top:84px}
html.nav-open{overflow:hidden}
body{margin:0;background:var(--color-bg);color:var(--color-text);font-family:var(--font-body);line-height:1.7;-webkit-font-smoothing:antialiased;overflow-wrap:break-word}
body,main,section,article,header,footer{max-width:100%}
img,svg,video,canvas{display:block;max-width:100%}
img{height:auto}
button,input,select,textarea{font:inherit}
button{color:inherit}
a{color:inherit;text-decoration:none}
p,ul,ol,blockquote,pre,table{margin-top:0}
ul,ol{padding-left:1.35rem}
h1,h2,h3,h4{margin:0;color:var(--color-text);font-family:var(--font-display);line-height:1.16;text-wrap:balance}
h1{font-size:clamp(52px,5.4vw,68px);font-weight:800;letter-spacing:-.02em}
h2{font-size:clamp(34px,4vw,52px);font-weight:800;letter-spacing:-.018em}
h3{font-size:clamp(21px,2.2vw,28px);font-weight:750}
h4{font-size:18px;font-weight:700}
code,kbd,samp,pre{font-family:var(--font-mono)}
code{overflow-wrap:anywhere}
pre{max-width:100%;overflow-x:auto;padding:20px;border:1px solid var(--color-border);border-radius:var(--radius-sm);background:var(--color-ink);color:var(--color-ink-text);-webkit-overflow-scrolling:touch}
hr{border:0;border-top:1px solid var(--color-border);margin:48px 0}
table{border-collapse:collapse}
th,td{text-align:left}
summary{cursor:pointer}
.no-break{white-space:nowrap}
.wrap{width:100%;max-width:calc(var(--content-width) + var(--gutter)*2);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);overflow-x:clip}
.section-tight{padding-top:56px;padding-bottom:56px;overflow-x:clip}
.section-ink{background:var(--color-ink);color:var(--color-ink-text)}
.section-ink h1,.section-ink h2,.section-ink h3{color:var(--color-ink-text)}
.section-head{max-width:760px;margin-bottom:42px}
.section-head p{margin:14px 0 0;color:var(--color-muted);font-size:18px}
.eyebrow{display:inline-flex;align-items:center;gap:9px;min-height:28px;margin:0 0 14px;padding:4px 12px;border:1px solid var(--color-border);border-radius:var(--radius-pill);font-family:var(--font-mono);font-size:12px;letter-spacing:.08em;color:var(--color-muted)}
.eyebrow::before{content:"";width:6px;height:6px;flex:0 0 auto;border-radius:50%;background:var(--color-accent);box-shadow:0 0 8px var(--color-glow-strong)}
.accent-text{background:linear-gradient(118deg,var(--color-accent),var(--color-accent-soft));background-clip:text;-webkit-background-clip:text;color:transparent}
.muted{color:var(--color-muted)}
.mono{font-family:var(--font-mono)}
.card,.panel{min-width:0;border:1px solid var(--color-border);border-radius:var(--radius-md);background:var(--color-panel)}
.card{padding:26px;box-shadow:var(--shadow-card)}
.panel{padding:clamp(22px,4vw,40px)}
.grid-2,.grid-3,.grid-4{display:grid;gap:20px}
.grid-2{grid-template-columns:repeat(2,minmax(0,1fr))}
.grid-3{grid-template-columns:repeat(3,minmax(0,1fr))}
.grid-4{grid-template-columns:repeat(4,minmax(0,1fr))}
.grid-2>*,.grid-3>*,.grid-4>*,.flex-row>*{min-width:0}
.flex-row{display:flex;align-items:center;gap:16px}
.btn{display:inline-flex;align-items:center;justify-content:center;gap:9px;min-height:46px;padding:11px 24px;border:1px solid transparent;border-radius:var(--radius-md);font-family:var(--font-display);font-size:15px;font-weight:700;line-height:1.2;cursor:pointer;transition:transform var(--transition-fast),box-shadow var(--transition-fast),background var(--transition-fast),border-color var(--transition-fast)}
.btn:hover{transform:translateY(-1px)}
.btn-primary{background:linear-gradient(135deg,var(--color-accent),var(--color-accent-dark));color:var(--color-on-accent);box-shadow:0 0 24px var(--color-glow),inset 0 1px var(--color-accent-soft)}
.btn-primary:hover{box-shadow:0 0 34px var(--color-glow-strong),inset 0 1px var(--color-accent-soft)}
.btn-secondary{border-color:var(--color-border);background:var(--color-panel);color:var(--color-text)}
.btn-secondary:hover{border-color:var(--color-accent-dark)}
.btn-dark{border-color:var(--color-ink-line);background:var(--color-ink-panel);color:var(--color-ink-text)}
.btn[aria-disabled="true"],.btn:disabled{cursor:not-allowed;opacity:.55;transform:none}
a:focus-visible,button:focus-visible,summary:focus-visible,input:focus-visible,select:focus-visible,textarea:focus-visible,[role="tab"]:focus-visible{outline:var(--focus-ring);outline-offset:3px}
.reveal{transition:opacity .6s ease,transform .6s ease}
.reveal.pending{opacity:0;transform:translateY(16px)}
.reveal.shown{opacity:1;transform:none}
.site-topbar{position:relative;z-index:40;height:var(--header-height);display:flex;align-items:center;gap:36px;padding-inline:var(--gutter);border-bottom:1px solid var(--color-ink-line);background:var(--color-ink)}
.site-brand{display:flex;align-items:center;gap:11px;flex:0 0 auto;color:var(--color-ink-text);font-family:var(--font-display);font-size:17px;font-weight:800;letter-spacing:.02em}
.site-brand img{width:30px;height:30px}
.brand-local{color:var(--color-ink-muted);font-size:14px;font-weight:550}
.desktop-nav{display:flex;align-items:center;gap:clamp(14px,1.8vw,27px)}
.desktop-nav a{display:inline-flex;align-items:center;min-height:44px;color:var(--color-ink-muted);font-size:13.5px;white-space:nowrap;transition:color var(--transition-fast)}
.desktop-nav a:hover,.desktop-nav a.is-active{color:var(--color-ink-text)}
.desktop-nav a.is-active{font-weight:650}
.header-tools{position:relative;display:flex;align-items:center;gap:14px;margin-left:auto}
.language-control{position:relative}
.language-button{display:inline-flex;align-items:center;justify-content:center;min-width:44px;min-height:44px;padding:6px 4px;border:0;background:transparent;color:var(--color-ink-muted);cursor:pointer}
.language-menu{position:absolute;top:calc(100% + 8px);right:0;z-index:45;display:none;width:154px;padding:7px;border:1px solid var(--color-ink-line);border-radius:var(--radius-sm);background:var(--color-ink-panel);box-shadow:var(--shadow-ink)}
.language-menu.is-open{display:block}
.language-menu a{display:flex;align-items:center;min-height:40px;padding:7px 10px;border-radius:var(--radius-xs);color:var(--color-ink-muted);font-size:13px}
.language-menu a:hover,.language-menu a[aria-current="true"]{background:var(--color-ink);color:var(--color-ink-text)}
.login-button{display:inline-flex;align-items:center;justify-content:center;min-height:38px;padding:7px 19px;border:1px solid var(--color-accent-dark);border-radius:var(--radius-sm);color:var(--color-accent);font-size:13px;font-weight:650}
.login-button:hover{background:var(--color-accent);color:var(--color-on-accent)}
.menu-toggle{display:none;align-items:center;justify-content:center;min-width:44px;min-height:44px;padding:0;border:0;background:transparent;color:var(--color-ink-text);cursor:pointer}
.menu-toggle svg{width:22px;height:22px}
.mobile-nav{position:absolute;top:var(--header-height);left:0;right:0;z-index:43;display:none;max-height:calc(100dvh - var(--header-height));overflow-y:auto;overscroll-behavior:contain;padding:10px var(--gutter) 20px;border-bottom:1px solid var(--color-ink-line);background:var(--color-ink)}
.mobile-nav.is-open{display:block}
.mobile-nav a{display:flex;align-items:center;width:100%;min-height:46px;padding:10px 4px;border-bottom:1px solid var(--color-ink-line);color:var(--color-ink-muted)}
.mobile-nav a.is-active{color:var(--color-ink-text);font-weight:700}
.mobile-nav-group{padding-top:10px}
.mobile-nav-label{display:block;padding:10px 4px 4px;color:var(--color-ink-muted);font-family:var(--font-mono);font-size:11px;letter-spacing:.12em}
.nav-veil{position:fixed;inset:var(--header-height) 0 0;z-index:35;display:none;background:var(--color-overlay)}
.nav-veil.is-open{display:block}
.site-footer{overflow-x:clip;border-top:1px solid var(--color-ink-line);background:var(--color-ink);color:var(--color-ink-muted)}
.footer-grid{display:grid;grid-template-columns:1.25fr 1fr 1.2fr .8fr;gap:44px;padding-top:64px;padding-bottom:48px}
.footer-brand{display:flex;align-items:center;gap:11px;margin-bottom:16px;color:var(--color-ink-text);font-family:var(--font-display);font-weight:800}
.footer-brand img{width:34px;height:34px}
.footer-copy{max-width:330px;font-size:14px}
.footer-title{margin:0 0 14px;color:var(--color-ink-text);font-size:13px;font-weight:700}
.footer-links{display:grid;gap:7px}
.footer-links a{display:inline-flex;align-items:center;min-height:28px;font-size:13px}
.footer-links a:hover{color:var(--color-ink-text)}
.footer-bottom{display:flex;justify-content:space-between;gap:24px;padding-top:20px;padding-bottom:28px;border-top:1px solid var(--color-ink-line);font-size:12px}
.footer-legal{display:flex;flex-wrap:wrap;gap:16px}
.prose{font-size:17px}
.prose h2{margin-top:2.2em;margin-bottom:.65em}
.prose h3{margin-top:1.8em;margin-bottom:.55em}
.prose p,.prose li{color:var(--color-text)}
.prose a:not(.btn){color:var(--color-accent-dark);text-decoration:underline;text-underline-offset:3px}
.prose img{border-radius:var(--radius-md)}
@media(max-width:1120px){
  .site-topbar{gap:22px}
  .desktop-nav{gap:13px}
  .desktop-nav a{font-size:12.5px}
  .brand-local{display:none}
  .footer-grid{grid-template-columns:repeat(2,minmax(0,1fr))}
}
@media(max-width:900px){
  .desktop-nav,.language-control{display:none}
  .header-tools{margin-left:auto}
  .menu-toggle{display:inline-flex}
  .grid-4{grid-template-columns:repeat(2,minmax(0,1fr))}
  .grid-3{grid-template-columns:repeat(2,minmax(0,1fr))}
}
@media(max-width:768px){
  h1{font-size:clamp(28px,9.8vw,40px);line-height:1.12;letter-spacing:-.015em}
  h2{font-size:clamp(28px,8vw,38px)}
  .section-head p{font-size:16px}
  .footer-grid{grid-template-columns:1fr}
  .footer-bottom{flex-direction:column}
}
@media(max-width:640px){
  :root{--gutter:16px}
  .site-topbar{padding-inline:16px;gap:10px}
  .site-brand{gap:8px}
  .site-brand img{width:28px;height:28px}
  .login-button{padding-inline:13px}
  .grid-2,.grid-3,.grid-4{grid-template-columns:1fr}
  .no-break{white-space:normal}
  .flex-row{flex-wrap:wrap}
  .tilt,.tilt-left,.tilt-right{transform:none!important}
  .card,.panel{padding:20px}
  .prose{font-size:16px}
}
@media(prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  *,*::before,*::after{animation:none!important;transition:none!important}
  .reveal,.reveal.pending{opacity:1!important;transform:none!important}
}