:root {
  --bg:#FDFCFA;
  --panel:#FFFFFF;
  --panel-2:#F3F2EE;
  --panel-warm:#FAF9F5;
  --border:#E6E4DE;
  --border-strong:#CFCCC4;
  --border-soft:rgba(30,43,36,.07);
  --accent:#3FBF6F;
  --accent-2:#5BCC85;
  --accent-dark:#1E7A43;
  --text:#1E2B24;
  --muted:#5D6660;
  --muted-2:#737B75;
  --faint:#8E958F;
  --ghost:#A3A9A2;
  --success:#1E9E57;
  --warn:#E3A21A;
  --error:#D64545;
  --pink:#F6D3F4;
  --green:#CDEFC0;
  --yellow:#FFE3A3;
  --blue:#CFE7FF;
  --pink-2:#EDB5EA;
  --green-2:#A6E092;
  --yellow-2:#FFD27A;
  --blue-2:#A8D2FF;
  --sh-pink:rgba(196,96,190,.14);
  --sh-green:rgba(63,191,111,.14);
  --sh-yellow:rgba(227,162,26,.16);
  --sh-blue:rgba(64,140,222,.14);
  --sh-accent:rgba(30,122,67,.45);
  --accent-10:rgba(63,191,111,.10);
  --accent-14:rgba(63,191,111,.14);
  --tint-deep:rgba(63,191,111,.055);
  --tint-end:rgba(63,191,111,.02);
  --grid:rgba(30,43,36,.04);
  --hi:rgba(255,255,255,.95);
  --hi-40:rgba(255,255,255,.4);
  --hi-70:rgba(255,255,255,.7);
  --ink-04:rgba(30,43,36,.04);
  --ink-08:rgba(30,43,36,.08);
  --ink-12:rgba(30,43,36,.12);
  --veil:rgba(30,43,36,.32);
  --glow-a:rgba(255,227,163,.62);
  --glow-b:rgba(255,200,110,.16);
  --glow-0:rgba(255,227,163,0);
  --clear:transparent;
  --flag-white:#FFFFFF;
  --flag-red:#C8102E;
  --flag-jp:#BC002D;
  --flag-hk:#DE2910;
  --flag-sg:#EF3340;
  --flag-ch:#D52B1E;
  --flag-navy:#1F3A7A;
  --flag-navy-au:#00247D;
  --font-display:"Inter","Noto Sans SC","PingFang SC","Hiragino Sans GB","Microsoft YaHei",system-ui,sans-serif;
  --font-body:"Inter","Noto Sans SC","PingFang SC","Hiragino Sans GB","Microsoft YaHei",system-ui,sans-serif;
  --font-mono:"JetBrains Mono",ui-monospace,"SFMono-Regular",Menlo,Consolas,monospace;
  --r-tile:22px;
  --r-card:28px;
  --r-panel:20px;
  --r-window:14px;
  --r-pill:999px;
  --r-sm:6px;
  --r-medium:10px;
  --r-highlight:10px;
  --r-round:50%;
  --gutter:32px;
  --content-width:1312px;
  --reading-width:800px;
  --header-height:68px;
  --anchor-offset:84px;
  --toc-offset:80px;
  --chapter-offset:160px;
  --text-xs:12px;
  --text-sm:14px;
  --text-base:16px;
  --text-lead:18px;
  --text-h3:24px;
  --text-h2:clamp(28px,3.2vw,40px);
  --text-h1:clamp(52px,4.6vw,66px);
  --weight-normal:400;
  --weight-medium:500;
  --weight-semibold:600;
  --weight-bold:700;
  --weight-display:800;
  --shadow-panel:0 20px 40px -20px var(--sh-green),inset 0 1px 0 var(--hi);
  --shadow-button:inset 0 1px 0 var(--hi-40),0 10px 20px -10px var(--sh-accent);
  --ease-out:cubic-bezier(.2,.7,.2,1);
  --reveal-time:.35s;
}
*,*::before,*::after { box-sizing:border-box }
html { -webkit-text-size-adjust:100%;scroll-padding-top:var(--anchor-offset);scroll-behavior:smooth }
html.nav-open { overflow:hidden }
body {
  margin:0;font-family:var(--font-body);font-size:var(--text-base);line-height:1.7;color:var(--text);
  background-color:var(--bg);
  background-image:linear-gradient(var(--grid) 1px,var(--clear) 1px),linear-gradient(90deg,var(--grid) 1px,var(--clear) 1px);
  background-size:44px 44px;background-position:center top;
  -webkit-font-smoothing:antialiased;text-rendering:optimizeLegibility;
}
[hidden] { display:none!important }
img { max-width:100%;height:auto;vertical-align:middle }
svg { flex-shrink:0;vertical-align:middle }
button,input,select,textarea { font:inherit;color:inherit }
button { cursor:pointer }
a { color:inherit;text-underline-offset:4px }
:where(a,button,input,select,textarea,summary,[tabindex]):focus-visible { outline:2px solid var(--accent-dark);outline-offset:3px }
button:disabled { cursor:not-allowed }
h1,h2,h3 { font-family:var(--font-display);line-height:1.2;text-wrap:balance;overflow-wrap:break-word }
h1 { font-size:var(--text-h1);font-weight:var(--weight-display);letter-spacing:-.02em;line-height:1.1 }
h2 { font-size:var(--text-h2);font-weight:var(--weight-bold);letter-spacing:-.02em }
h3 { font-size:var(--text-h3);font-weight:var(--weight-bold) }
p { margin:0 0 1.25em }
h1,h2,h3,p,li { min-width:0 }
code { font-family:var(--font-mono);font-size:.9em;overflow-wrap:anywhere }
pre { max-width:100%;overflow-x:auto;padding:20px;border:1px solid var(--border);border-radius:var(--r-window);background:var(--panel-2) }
pre code { overflow-wrap:normal;white-space:pre }
.wrap { 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:64px;padding-bottom:64px }
.section-head { margin-bottom:28px;max-width:760px }
.section-head h2 { margin:0 0 16px }
.section-head p { color:var(--muted) }
.no-break { white-space:nowrap }
.num,.mono { font-family:var(--font-mono);font-variant-numeric:tabular-nums }
.num { font-weight:var(--weight-semibold);letter-spacing:-.01em }
[data-counter] { display:inline-block;min-width:3ch;text-align:center;font-family:var(--font-mono);font-variant-numeric:tabular-nums }
.grid-two { display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:24px }
.grid-three { display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:24px }
:where(.grid-two,.grid-three)>* { min-width:0 }
.stack { display:grid;gap:24px }
.cluster { display:flex;align-items:center;flex-wrap:wrap;gap:12px }
.muted { color:var(--muted) }
.kicker { font:var(--weight-medium) var(--text-sm)/1.5 var(--font-mono);letter-spacing:.08em;color:var(--accent-dark);text-transform:uppercase }
.panel,.card { background:var(--panel);border:1px solid var(--border);border-radius:var(--r-card);padding:28px;box-shadow:var(--shadow-panel);min-width:0 }
.panel-sunk { background:var(--panel-2);border-radius:var(--r-panel);padding:28px;min-width:0 }
.btn {
  display:inline-flex;align-items:center;justify-content:center;gap:8px;min-height:46px;
  padding:10px 24px;border:1px solid var(--border-strong);border-radius:var(--r-pill);
  font-size:var(--text-base);font-weight:var(--weight-semibold);line-height:1.4;
  text-decoration:none;background:var(--panel);color:var(--text);flex-shrink:0;white-space:nowrap;max-width:100%;
}
.btn svg { width:18px;height:18px }
.btn-primary { background:linear-gradient(180deg,var(--accent-2),var(--accent));border-color:var(--accent);box-shadow:var(--shadow-button);font-weight:var(--weight-bold) }
.btn-primary:hover,.btn-primary.is-hover { background:var(--accent) }
.btn-primary:active,.btn-primary.is-pressed { background:var(--green-2);box-shadow:inset 0 2px 4px var(--ink-12) }
.btn-secondary:hover { border-color:var(--text);background:var(--panel-2) }
.btn:disabled,.btn[aria-disabled="true"] { color:var(--muted);background:var(--panel-2);border-color:var(--border);box-shadow:none }
.btn.is-focus { outline:2px solid var(--accent-dark);outline-offset:3px }
.text-link { display:inline-flex;align-items:center;min-height:28px;font-weight:var(--weight-semibold);text-decoration:underline;text-underline-offset:4px }
.badge,.tag,.chip {
  display:inline-flex;align-items:center;gap:6px;padding:5px 11px;max-width:100%;
  border:1px solid var(--border);border-radius:var(--r-pill);background:var(--panel);
  color:var(--text);font-size:13.5px;line-height:1.4;vertical-align:middle;
}
.badge,.tag { overflow:hidden;overflow-wrap:anywhere }
.badge { background:var(--green);border-color:var(--green-2) }
.status-dot { width:6px;height:6px;flex-shrink:0;background:var(--success);border-radius:var(--r-round) }
.reveal { transition:opacity var(--reveal-time) var(--ease-out),transform var(--reveal-time) var(--ease-out) }
.reveal.pending { opacity:0;transform:translateY(16px) }
.reveal.shown { opacity:1;transform:none }
.defs { position:absolute;width:0;height:0;overflow:hidden }
#server-status { display:block;position:relative;min-width:0;max-width:100%;overflow:hidden;margin-block:24px }
#server-status+* { margin-top:24px }
#server-status>* { min-width:0;max-width:100% }

/* Header and navigation */
#site-header { position:relative;z-index:50 }
.topbar { position:relative;z-index:53;background:var(--bg);border-bottom:1px solid var(--border) }
.topbar .wrap { height:var(--header-height);display:flex;align-items:center;flex-wrap:nowrap;gap:32px }
.brand { display:inline-flex;align-items:center;gap:10px;text-decoration:none;color:var(--text);font-family:var(--font-display);font-weight:var(--weight-display);font-size:20px;letter-spacing:-.02em;white-space:nowrap;flex-shrink:0;line-height:1.2 }
.mark { width:32px;height:32px;flex:none }
.brand-zh { font-weight:var(--weight-medium);color:var(--muted) }
.tabs { display:flex;align-items:stretch;height:100%;margin-inline:auto;flex:1;min-width:0 }
.tabs ul { display:flex;align-items:center;list-style:none;margin:0;padding:0;gap:2px;height:100%;width:100%;justify-content:center }
.tabs li { height:100%;min-width:0 }
.tab { position:relative;display:flex;align-items:center;height:100%;padding:0 14px;color:var(--muted);font-size:15px;font-weight:var(--weight-medium);text-decoration:none;white-space:nowrap }
.tab:hover { color:var(--text) }
.tab.is-active { color:var(--text);font-weight:var(--weight-semibold) }
.tab.is-active::after { content:"";position:absolute;left:14px;right:14px;bottom:-1px;height:3px;border-radius:var(--r-sm) var(--r-sm) 0 0;background:var(--accent-dark) }
.nav-end { display:flex;align-items:center;gap:10px;flex-shrink:0 }
.lang-wrap { position:relative }
.lang { display:inline-flex;justify-content:center;align-items:center;gap:6px;min-width:44px;width:auto;height:40px;padding:0 12px;border:0;background:var(--clear);color:var(--muted);font:inherit;font-size:14px;cursor:pointer;border-radius:var(--r-pill);white-space:nowrap;list-style:none }
.lang::-webkit-details-marker { display:none }
.lang:hover { color:var(--text);background:var(--panel-2) }
.lang svg { width:16px;height:16px;flex:none }
.lang span { white-space:nowrap }
.ic-stroke { fill:none;stroke:currentColor;stroke-width:1.5;stroke-linecap:round;stroke-linejoin:round }
.lang-panel { position:absolute;z-index:60;top:calc(100% + 10px);right:0;width:184px;padding:8px;border:1px solid var(--border);border-radius:var(--r-window);background:var(--panel);box-shadow:var(--shadow-panel) }
.lang-panel a { display:flex;align-items:center;width:100%;min-height:44px;padding:8px 12px;text-decoration:none;border-radius:var(--r-sm);font-size:14px }
.lang-panel a:hover,.lang-panel a[aria-current] { background:var(--panel-2);color:var(--accent-dark) }
.login { display:inline-flex;align-items:center;justify-content:center;height:40px;padding:0 22px;border:1.5px solid var(--text);border-radius:var(--r-pill);background:var(--panel);color:var(--text);font-size:15px;font-weight:var(--weight-semibold);text-decoration:none;white-space:nowrap }
.login:hover { background:var(--panel-2) }
.menu-toggle { display:none;align-items:center;justify-content:center;flex-direction:column;gap:4px;min-width:44px;min-height:44px;padding:10px;border:1px solid var(--border);border-radius:var(--r-medium);background:var(--panel);color:var(--text) }
.menu-line { display:block;width:20px;height:2px;background:currentColor;border-radius:var(--r-sm) }
.menu-toggle[aria-expanded="true"] .menu-line:nth-child(1) { transform:translateY(6px) rotate(45deg) }
.menu-toggle[aria-expanded="true"] .menu-line:nth-child(2) { visibility:hidden }
.menu-toggle[aria-expanded="true"] .menu-line:nth-child(3) { transform:translateY(-6px) rotate(-45deg) }
.mobile-drawer { position:fixed;z-index:52;top:var(--header-height);right:0;left:0;height:calc(100dvh - var(--header-height));max-height:calc(100dvh - var(--header-height));overflow-y:auto;overscroll-behavior:contain;background:var(--panel);padding:20px var(--gutter) 32px;border-top:1px solid var(--border) }
.mobile-drawer a { display:flex;align-items:center;width:100%;min-height:48px;padding:12px 16px;text-decoration:none;border-radius:var(--r-medium);font-weight:var(--weight-medium) }
.mobile-drawer a:hover,.mobile-drawer a[aria-current] { background:var(--green);color:var(--text) }
.drawer-title { display:block;margin:20px 16px 8px;color:var(--muted);font-size:var(--text-sm) }
.nav-veil { position:fixed;z-index:51;top:var(--header-height);bottom:0;left:0;right:0;border:0;background:var(--veil) }
.skip-link { position:absolute;left:16px;top:-100px;z-index:70;padding:10px 18px;background:var(--panel);color:var(--text);border-radius:var(--r-pill) }
.skip-link:focus { top:8px }

/* Footer */
.site-footer { border-top:1px solid var(--border);background:var(--panel-warm);padding-top:56px;padding-bottom:24px }
.footer-grid { display:grid;grid-template-columns:1.25fr .85fr 1fr;gap:40px }
.footer-grid>* { min-width:0 }
.footer-intro { margin-top:18px;max-width:340px;color:var(--muted);font-size:var(--text-sm) }
.footer-title { margin:0 0 16px;font-size:var(--text-base);font-weight:var(--weight-bold) }
.footer-links { display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:4px 18px;list-style:none;padding:0;margin:0 }
.footer-links a { display:inline-flex;align-items:center;min-height:32px;font-size:var(--text-sm);color:var(--muted);text-decoration:none;overflow-wrap:anywhere }
.footer-links a:hover { color:var(--accent-dark);text-decoration:underline }
.footer-languages { display:flex;flex-wrap:wrap;gap:8px 20px;padding-top:28px;margin-top:28px;border-top:1px solid var(--border) }
.footer-languages a { display:inline-flex;align-items:center;min-height:32px;font-size:var(--text-sm);color:var(--muted) }
.footer-languages a[aria-current] { color:var(--accent-dark);font-weight:var(--weight-semibold) }
.footer-bottom { display:flex;align-items:center;justify-content:space-between;gap:16px;flex-wrap:wrap;margin-top:24px;padding-top:20px;border-top:1px solid var(--border);font-size:var(--text-sm);color:var(--muted) }
.footer-legal { display:flex;flex-wrap:wrap;gap:8px 20px }
.footer-legal a { display:inline-flex;align-items:center;min-height:28px }

@media (max-width:1200px) {
  .topbar .wrap { gap:18px }
  .tab { padding-inline:9px;font-size:14px }
  .tab.is-active::after { left:9px;right:9px }
  .lang { padding-inline:8px }
}
@media (max-width:1100px) {
  .tabs { display:none }
  .nav-end { margin-left:auto }
  .menu-toggle { display:inline-flex }
}
@media (min-width:1101px) {
  .mobile-drawer,.nav-veil { display:none!important }
}
@media (max-width:768px) {
  :root { --gutter:18px;--header-height:60px;--anchor-offset:76px;--toc-offset:72px;--chapter-offset:148px;--text-h1:36px }
  .topbar .wrap { gap:12px }
  .lang span { display:none }
  .login { height:36px;padding-inline:16px;font-size:14px }
  .grid-two,.grid-three,.footer-grid { grid-template-columns:minmax(0,1fr) }
  .section { padding-top:44px;padding-bottom:44px }
  .footer-grid { gap:28px }
  .footer-links { gap:6px 16px }
  .panel,.card,.panel-sunk { padding:22px }
}
@media (max-width:640px) {
  .no-break { white-space:normal }
  .tilt,.note { transform:none }
  .hero-glow,.decoration { max-width:100% }
}
@media (max-width:360px) {
  :root { --gutter:16px }
  .brand { font-size:18px;gap:7px }
  .mark { width:28px;height:28px }
  .nav-end { gap:4px }
  .login { padding-inline:12px }
  .topbar .wrap { gap:8px }
}
@media (prefers-reduced-motion:reduce) {
  html { scroll-behavior:auto }
  .reveal,.reveal.pending,.reveal.shown { opacity:1;transform:none;transition:none }
}