:root{
  color-scheme:light;
  --bg:#E9ECF7;
  --bg-top:#F1F3FB;
  --bg-bottom:#E2E6F4;
  --panel:#F7F8FD;
  --panel-2:#DCE1F1;
  --border:#CDD3EA;
  --accent:#7DBE31;
  --accent-hi:#97D04B;
  --accent-dark:#4C7D14;
  --accent-tint:rgba(125,190,49,.18);
  --text:#161A2B;
  --ink-2:#2B3252;
  --muted:#565C78;
  --success:#2E9E5B;
  --warn:#C98A12;
  --error:#D2413A;
  --white:#FFFFFF;
  --hero-top:#DDE3F5;
  --hero-bottom:#C9D3EE;
  --pocket-top:#E7EAF7;
  --pocket-bottom:#D4DAEE;
  --win-bar:#EDF0FA;
  --on-dark:#F7F8FD;
  --on-dark-muted:rgba(247,248,253,.66);
  --veil:rgba(247,248,253,.74);
  --hl:rgba(255,255,255,.8);
  --hl-soft:rgba(255,255,255,.42);
  --dot:rgba(22,26,43,.03);
  --line:rgba(22,26,43,.25);
  --line-soft:rgba(22,26,43,.08);
  --shadow-ink:rgba(38,52,118,.10);
  --shadow-ink-2:rgba(38,52,118,.17);
  --glow:rgba(125,190,49,.30);
  --glow-white:rgba(255,255,255,.55);
  --flag-red:#CC3440;
  --flag-blue:#27408F;
  --flag-white:#FFFFFF;
  --clear:transparent;
  --r-xl:32px;
  --r-lg:26px;
  --r-card:20px;
  --r-md:14px;
  --r-sm:12px;
  --r-pill:999px;
  --r-round:50%;
  --font-display:"Inter","Noto Sans SC","PingFang SC","Hiragino Sans","Apple SD Gothic Neo","Microsoft YaHei",system-ui,sans-serif;
  --font-body:"Inter","Noto Sans SC","PingFang SC","Hiragino Sans","Apple SD Gothic Neo","Microsoft YaHei",system-ui,sans-serif;
  --font-mono:"JetBrains Mono",ui-monospace,"SFMono-Regular",Menlo,Consolas,monospace;
  --weight-body:400;
  --weight-medium:500;
  --weight-semibold:600;
  --weight-bold:700;
  --weight-display:800;
  --size-body:17px;
  --size-small:14px;
  --size-h1:clamp(52px,4.6vw,66px);
  --size-h2:44px;
  --size-h3:24px;
  --tracking-display:-.025em;
  --tracking-cjk:-.02em;
  --gutter:24px;
  --wrap-width:1264px;
  --reading-width:840px;
  --space-section:96px;
  --header-height:112px;
  --toc-offset:16px;
  --anchor-offset:100px;
  --ease: cubic-bezier(.2,.65,.3,1);
  --duration:.2s;
  --reveal-duration:.35s;
  --shadow-panel:0 24px 56px -24px var(--shadow-ink);
  --focus-ring:2px solid var(--accent-dark);
}
*,*::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:var(--weight-body) var(--size-body)/1.7 var(--font-body);color:var(--text);background-color:var(--bg);background-image:linear-gradient(180deg,var(--bg-top) 0,var(--bg-bottom) 900px,var(--bg) 1200px);background-repeat:no-repeat;overflow-x:clip}
a{color:inherit;text-decoration:none}
button,input,select,textarea{font:inherit;color:inherit}
button,a,input,summary,select,textarea{-webkit-tap-highlight-color:var(--accent-tint)}
button{cursor:pointer}
button:disabled{cursor:not-allowed}
:where(a,button,input,select,textarea,summary,[tabindex]):focus-visible{outline:var(--focus-ring);outline-offset:4px}
img{display:block;max-width:100%;height:auto}
svg{vertical-align:middle;flex-shrink:0}
h1,h2,h3,h4,p,figure{margin-top:0}
h1,h2,h3{font-family:var(--font-display);text-wrap:balance;overflow-wrap:break-word}
h1{font-size:var(--size-h1);line-height:1.12;font-weight:var(--weight-display);letter-spacing:var(--tracking-display)}
:lang(zh) h1,:lang(zh) h2,:lang(zh) h3,:lang(ja) h1,:lang(ko) h1{letter-spacing:var(--tracking-cjk)}
h2{font-size:var(--size-h2);line-height:1.2;font-weight:var(--weight-display)}
h3{font-size:var(--size-h3);line-height:1.4;font-weight:var(--weight-bold)}
p{margin-bottom:1.2em}
small{font-size:var(--size-small)}
strong{font-weight:var(--weight-bold)}
ul,ol{padding-inline-start:1.5em}
li+li{margin-top:.3em}
code,kbd,pre{font-family:var(--font-mono)}
code{overflow-wrap:anywhere;word-break:break-word;background:var(--panel-2);border-radius:var(--r-sm);padding:.12em .35em}
pre{max-width:100%;overflow-x:auto;padding:24px;border-radius:var(--r-card);background:var(--text);color:var(--on-dark);font-size:var(--size-small);line-height:1.8}
pre code{padding:0;background:var(--clear);color:inherit;overflow-wrap:normal;word-break:normal;white-space:pre}
hr{border:0;border-top:1px solid var(--border);margin-block:32px}
[hidden]{display:none!important}
.no-break{white-space:nowrap}
.visually-hidden{position:absolute;width:1px;height:1px;margin:-1px;padding:0;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap;border:0}
.wrap{width:100%;max-width:var(--wrap-width);margin-inline:auto;padding-inline:var(--gutter)}
.reading-wrap{width:100%;max-width:var(--reading-width);margin-inline:auto;padding-inline:var(--gutter)}
.sec{padding-top:var(--space-section);padding-bottom:var(--space-section)}
.grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:24px}
.grid>*,:where(main,section,article,aside,nav,div){min-width:0}
.stack>*+*{margin-top:24px}
.actions{display:flex;align-items:center;flex-wrap:wrap;gap:12px}
.muted{color:var(--muted)}
.kw{color:var(--accent-dark)}
.mono{font-family:var(--font-mono)}
.panel{padding:32px;border-radius:var(--r-xl);background:var(--panel-2);box-shadow:inset 0 1px 0 var(--hl);overflow-x:clip}
.card{padding:24px;border-radius:var(--r-card);background:var(--panel);box-shadow:var(--shadow-panel),inset 0 1px 0 var(--hl)}
.texture{background-image:radial-gradient(var(--dot) 1px,var(--clear) 1.5px);background-size:18px 18px}
.decorated{position:relative;overflow-x:clip}
.btn,.btn-primary,.btn-secondary{display:inline-flex;align-items:center;justify-content:center;gap:8px;height:48px;padding:0 24px;border:0;border-radius:var(--r-pill);font:var(--weight-bold) 16px/1 var(--font-body);white-space:nowrap;flex-shrink:0;cursor:pointer;transition:transform var(--duration),box-shadow var(--duration),background-color var(--duration)}
.btn svg,.btn-primary svg,.btn-secondary svg{width:18px;height:18px}
.btn--primary,.btn-primary{background:linear-gradient(180deg,var(--accent-hi),var(--accent));color:var(--text);box-shadow:inset 0 1px 0 var(--hl-soft),0 10px 20px -12px var(--accent-dark)}
.btn--primary:hover,.btn-primary:hover{transform:translateY(-1px);box-shadow:inset 0 1px 0 var(--hl-soft),0 14px 24px -12px var(--accent-dark)}
.btn--ghost,.btn-secondary{height:60px;padding:0 26px;background:var(--clear);color:var(--text);box-shadow:inset 0 0 0 1.5px var(--text)}
.btn--ghost:hover,.btn-secondary:hover{background:var(--veil)}
.btn--quiet{background:var(--panel-2);color:var(--text)}
.btn:active,.btn-primary:active,.btn-secondary:active{transform:translateY(0)}
.btn:disabled,.btn[aria-disabled="true"]{background:var(--panel-2);color:var(--muted);box-shadow:none;transform:none}
.btn[aria-disabled="true"]{pointer-events:none}
.text-link{text-decoration:underline;text-underline-offset:4px;min-height:24px;display:inline-flex;align-items:center}
.reveal{transition:opacity var(--reveal-duration) var(--ease),transform var(--reveal-duration) var(--ease)}
.reveal.pending{opacity:0;transform:translateY(16px)}
.reveal.shown{opacity:1;transform:none}
#server-status{position:relative;display:flow-root;max-width:100%;overflow:hidden;margin:32px 0}
#server-status+*{margin-top:32px}
#server-status>*{max-width:100%;min-width:0}

/* Shared top chrome */
#site-header{position:relative;z-index:70}
.notice{background:var(--text);color:var(--on-dark-muted);font-size:14px;line-height:1.4}
.notice__in{min-height:40px;display:flex;align-items:center;justify-content:space-between;gap:24px;padding:8px 88px}
.notice__lead{display:flex;align-items:center;gap:16px;flex-wrap:wrap}
.notice__tag{color:var(--accent);font-weight:var(--weight-bold);letter-spacing:.01em}
.notice__link{display:inline-flex;align-items:center;min-height:24px;color:var(--on-dark);font-weight:var(--weight-semibold);text-decoration:underline;text-decoration-thickness:1px;text-underline-offset:5px;white-space:nowrap}
.notice__link:hover{text-decoration-thickness:2px}
.topbar{position:relative;z-index:73}
.topbar__in{height:72px;display:flex;align-items:center;gap:32px;padding:0 88px}
.brand{display:inline-flex;align-items:center;gap:10px;flex:none;line-height:1;min-height:34px}
.brand img{width:34px;height:34px;flex:none}
.brand__en{font-family:var(--font-display);font-weight:var(--weight-display);font-size:20px;letter-spacing:-.02em;color:var(--text)}
.brand__zh{font-size:14px;font-weight:var(--weight-medium);color:var(--muted)}
.menu{flex:1;display:flex;justify-content:center;min-width:0}
.menu ul{list-style:none;margin:0;padding:0;display:flex;align-items:center}
.menu li{display:flex;align-items:center;margin:0}
.menu li+li::before{content:"·";padding:0 11px;color:var(--muted);font-weight:var(--weight-bold)}
.menu a{position:relative;display:inline-flex;align-items:center;min-height:28px;padding:6px 1px;font-size:15px;font-weight:var(--weight-medium);color:var(--muted);line-height:1.2;white-space:nowrap;transition:color var(--duration)}
.menu a:hover{color:var(--text)}
.menu a[aria-current="page"]{color:var(--text);font-weight:var(--weight-bold)}
.menu a[aria-current="page"]::after{content:"";position:absolute;left:50%;bottom:-6px;width:5px;height:5px;margin-left:-2.5px;border-radius:var(--r-round);background:var(--accent-dark)}
.tools{display:flex;align-items:center;gap:12px;flex-shrink:0}
.language{position:relative}
.lang{display:inline-flex;align-items:center;justify-content:center;gap:6px;height:40px;width:auto;min-width:44px;padding:0 14px;border:0;border-radius:var(--r-pill);background:var(--veil);box-shadow:inset 0 0 0 1px var(--border);font:var(--weight-medium) 14px/1 var(--font-body);color:var(--text);cursor:pointer}
.lang__txt{white-space:nowrap}
.lang svg{width:16px;height:16px;color:var(--muted)}
.lang-panel{position:absolute;z-index:80;right:0;top:calc(100% + 10px);width:184px;padding:8px;border:1px solid var(--border);border-radius:var(--r-card);background:var(--panel);box-shadow:var(--shadow-panel)}
.lang-panel a{display:flex;align-items:center;width:100%;min-height:44px;padding:8px 12px;font-size:14px;border-radius:var(--r-sm)}
.lang-panel a:hover,.lang-panel a[aria-current="true"]{background:var(--panel-2);color:var(--text)}
.login{display:inline-flex;align-items:center;justify-content:center;gap:8px;height:40px;padding:0 20px 0 16px;border-radius:var(--r-pill);background:var(--text);color:var(--on-dark);font-size:14px;font-weight:var(--weight-semibold);line-height:1;white-space:nowrap;transition:transform var(--duration)}
.login svg{width:16px;height:16px}
.login:hover{transform:translateY(-1px)}
.menu-toggle{display:none;align-items:center;justify-content:center;min-width:44px;min-height:44px;padding:10px;border:1px solid var(--border);border-radius:var(--r-sm);background:var(--panel);color:var(--text)}
.menu-toggle svg{width:22px;height:22px}
.nav-drawer{display:none;position:fixed;z-index:72;top:var(--header-height);right:0;left:0;height:calc(100dvh - var(--header-height));max-height:calc(100dvh - var(--header-height));padding:16px var(--gutter) 40px;background:var(--panel);overflow-y:auto;overscroll-behavior:contain}
.nav-drawer a{display:flex;align-items:center;width:100%;min-height:48px;padding:12px 16px;border-radius:var(--r-sm);font-size:16px}
.nav-drawer a:hover,.nav-drawer a[aria-current]{background:var(--panel-2)}
.drawer-label{margin:20px 16px 8px;font-size:14px;color:var(--muted);font-weight:var(--weight-semibold)}
.nav-veil{display:none;position:fixed;z-index:71;inset:var(--header-height) 0 0;background:var(--line)}
/* Footer */
.site-footer{margin-top:var(--space-section);background:var(--panel-2);border-radius:var(--r-xl) var(--r-xl) 0 0;padding-top:56px;padding-bottom:32px}
.footer-grid{display:grid;grid-template-columns:1.4fr 1fr 1fr 1fr;gap:40px}
.footer-brand p{max-width:25em;margin-top:20px;color:var(--muted);font-size:15px}
.footer-title{font-size:16px;font-weight:var(--weight-bold);margin-bottom:16px}
.footer-links{display:grid;gap:5px;list-style:none;margin:0;padding:0}
.footer-links li{margin:0}
.footer-links a{display:inline-flex;align-items:center;min-height:30px;font-size:14px;color:var(--muted)}
.footer-links a:hover{color:var(--text);text-decoration:underline;text-underline-offset:4px}
.footer-bottom{margin-top:40px;padding-top:24px;border-top:1px solid var(--line);display:flex;align-items:center;justify-content:space-between;gap:16px;flex-wrap:wrap;font-size:14px;color:var(--muted)}
.footer-legal{display:flex;gap:20px;flex-wrap:wrap}
.footer-legal a{display:inline-flex;align-items:center;min-height:24px}
.prose{overflow-wrap:break-word}
.prose h2{margin-top:64px;font-size:32px}
.prose h3{margin-top:32px}
.prose p a{text-decoration:underline;text-underline-offset:4px;color:var(--accent-dark)}
.prose img{border-radius:var(--r-card)}
.prose section[id]{scroll-margin-top:var(--anchor-offset)}
body:has(.toc-tabs) section[id]{scroll-margin-top:var(--anchor-offset)}
@media(min-width:961px) and (max-width:1320px){
  :lang(en) .topbar__in,:lang(ja) .topbar__in,:lang(ko) .topbar__in{gap:16px;padding-inline:24px}
  :lang(en) .menu li+li::before,:lang(ja) .menu li+li::before,:lang(ko) .menu li+li::before{padding-inline:5px}
  :lang(en) .menu a,:lang(ja) .menu a,:lang(ko) .menu a{font-size:12px}
  :lang(en) .tools,:lang(ja) .tools,:lang(ko) .tools{gap:8px}
}
@media(max-width:1180px){
  .notice__in,.topbar__in{padding-left:40px;padding-right:40px}
  .brand__zh{display:none}
  .menu li+li::before{padding:0 7px}
  .menu a{font-size:14px}
  .topbar__in{gap:20px}
}
@media(max-width:960px){
  .topbar__in{height:72px;flex-wrap:nowrap;gap:16px}
  .menu{display:none}
  .tools{margin-left:auto}
  .menu-toggle{display:inline-flex}
  html.nav-open .nav-drawer{display:block}
  html.nav-open .nav-veil{display:block}
  .footer-grid{grid-template-columns:repeat(2,minmax(0,1fr))}
}
@media(max-width:768px){
  :root{--space-section:72px;--size-h1:clamp(28px,9vw,40px);--size-h2:30px;--gutter:16px}
  .notice__in{padding:8px 16px;font-size:13px}
  .notice__sub{display:none}
  .topbar__in{padding-inline:16px}
  .lang__txt{display:none}
  .lang{padding-inline:12px}
  .grid{grid-template-columns:1fr}
  .sec{padding-top:var(--space-section);padding-bottom:var(--space-section)}
  .panel{padding:24px}
}
@media(max-width:640px){
  .no-break{white-space:normal}
  .tilt,.folder,[data-tilt]{transform:none}
  .decorated>*{max-width:100%}
  .footer-grid{grid-template-columns:1fr;gap:28px}
  .prose h2{font-size:28px}
  .prose h3{font-size:22px}
}
@media(max-width:420px){
  .topbar__in{gap:8px}
  .tools{gap:6px}
  .brand{gap:6px}
  .brand img{width:28px;height:28px}
  .brand__en{font-size:17px}
  .login{padding-inline:12px;font-size:13px}
  .login svg{display:none}
}
@media(prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  *,*::before,*::after{transition:none!important;animation:none!important}
  .reveal,.reveal.pending{opacity:1;transform:none}
}