:root {
  --bg:#F3EADA;
  --bg-panel:#FCF8F0;
  --bg-panel-2:#EADFC9;
  --border:#DACDB2;
  --accent:#6E6A27;
  --accent-dark:#46441A;
  --text:#2A2216;
  --text-muted:#6E6250;
  --success:#3E7B4F;
  --warn:#B7791F;
  --error:#B23A2E;
  --mist:#2F5D8C;
  --mist-wash:#E3E8EA;
  --mist-line:#CFD8DC;
  --hero-top:#F8F2E5;
  --hero-bottom:#EEE3CF;
  --board-from:#5A5A28;
  --board-to:#3E3F1C;
  --paper-rgb:252 248 240;
  --olive-rgb:110 106 39;
  --ink-rgb:42 34 22;
  --deep-rgb:26 26 9;
  --success-rgb:62 123 79;
  --flag-red:#C3392E;
  --flag-white:#FBF9F4;
  --flag-blue:#2C3C6C;
  --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,-apple-system,"Segoe UI",sans-serif;
  --font-mono:"JetBrains Mono",ui-monospace,"SFMono-Regular",Menlo,Consolas,monospace;
  --weight-body:400;
  --weight-medium:500;
  --weight-brand:600;
  --size-body:16px;
  --size-small:14px;
  --size-caption:12px;
  --size-h1:64px;
  --size-h2:36px;
  --size-h3:22px;
  --r-sm:6px;
  --r-md:8px;
  --r-chip:10px;
  --r-card:14px;
  --r-board:24px;
  --r-pill:999px;
  --r-dot:50%;
  --wrap:1160px;
  --gutter:40px;
  --board-h:372px;
  --grain:.03;
  --section-space:72px;
  --anchor-offset:84px;
  --toc-offset:16px;
  --toc-landing:100px;
  --ease:200ms ease;
  --reveal-time:500ms;
  --shadow-panel:inset 0 1px 0 rgb(var(--paper-rgb) / 1),0 10px 28px -10px rgb(var(--olive-rgb) / .16),0 2px 6px rgb(var(--olive-rgb) / .08);
  --shadow-chip:inset 0 1px 0 rgb(var(--paper-rgb) / 1),0 16px 36px -12px rgb(var(--olive-rgb) / .32),0 3px 8px rgb(var(--olive-rgb) / .10);
  --shadow-board:0 46px 96px -22px rgb(var(--olive-rgb) / .12),0 18px 40px -16px rgb(var(--olive-rgb) / .12),0 4px 10px rgb(var(--deep-rgb) / .06);
  --shadow-button:inset 0 1px 0 rgb(var(--paper-rgb) / .14),0 10px 22px -10px rgb(var(--ink-rgb) / .55);
  --sh-g1:0 10px 22px -8px rgb(var(--deep-rgb) / .22);
  --sh-g2:0 14px 28px -10px rgb(var(--deep-rgb) / .27),0 2px 6px rgb(var(--deep-rgb) / .08);
  --sh-g3:0 18px 36px -12px rgb(var(--deep-rgb) / .32),0 3px 8px rgb(var(--deep-rgb) / .10);
  --sh-g4:0 24px 46px -14px rgb(var(--deep-rgb) / .38),0 4px 10px rgb(var(--deep-rgb) / .12);
  --paper-noise:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='160' height='160' viewBox='0 0 160 160'%3E%3Cfilter id='p'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='.84' numOctaves='3' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='160' height='160' filter='url(%23p)'/%3E%3C/svg%3E");
}
*,*::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;background:var(--bg);color:var(--text);font-family:var(--font-body);font-size:var(--size-body);font-weight:var(--weight-body);line-height:1.6;-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale }
body::before { content:"";position:fixed;inset:0;pointer-events:none;z-index:60;background-image:var(--paper-noise);opacity:var(--grain);mix-blend-mode:multiply }
a { color:inherit;text-underline-offset:.2em }
button,input,select,textarea { font:inherit }
button { cursor:pointer }
img { display:block;max-width:100%;height:auto }
svg { flex-shrink:0 }
h1,h2,h3 { font-family:var(--font-display);font-weight:var(--weight-body);text-wrap:balance;overflow-wrap:break-word }
h1 { margin:0;font-size:clamp(52px,5vw,var(--size-h1));line-height:1.15;letter-spacing:-.02em }
h2 { margin:0 0 24px;font-size:var(--size-h2);line-height:1.25;letter-spacing:-.01em }
h3 { margin:0 0 16px;font-size:var(--size-h3);line-height:1.4 }
p { margin:0 0 20px }
ul,ol { margin:0 0 20px;padding-left:24px }
[hidden] { display:none!important }
:focus-visible { outline:2px solid var(--mist);outline-offset:2px;border-radius:var(--r-sm) }
.wrap { width:100%;max-width:calc(var(--wrap) + var(--gutter) * 2);padding-inline:var(--gutter);margin-inline:auto }
.section { padding-top:var(--section-space);padding-bottom:var(--section-space) }
.mono { font-family:var(--font-mono);font-variant-numeric:tabular-nums }
.no-break { white-space:nowrap }
.muted { color:var(--text-muted) }
.link { color:var(--mist) }
.panel,.card { min-width:0;border:1px solid var(--border);background:var(--bg-panel);box-shadow:var(--shadow-panel) }
.panel { border-radius:var(--r-board);padding:32px }
.card { border-radius:var(--r-card);padding:24px }
.grid { display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:24px }
.grid>* { min-width:0 }
.reading-wrap { max-width:860px }
.prose { min-width:0;overflow-wrap:break-word }
.prose h2 { margin-top:48px }
.prose h3 { margin-top:32px }
.prose a:not(.btn):not(.btn-primary) { color:var(--mist) }
.prose li { margin-bottom:8px }
code { font-family:var(--font-mono);font-size:.88em;overflow-wrap:anywhere;background:var(--bg-panel-2);border-radius:var(--r-sm);padding:2px 5px }
pre { min-width:0;max-width:100%;overflow-x:auto;padding:20px;border:1px solid var(--border);border-radius:var(--r-md);background:var(--bg-panel-2) }
pre code { padding:0;background:transparent;white-space:pre;overflow-wrap:normal }
.decorated { position:relative;overflow-x:clip;max-width:100% }
#server-status { position:relative;display:block;min-width:0;max-width:100%;min-height:48px;overflow:hidden;margin-top:24px;margin-bottom:24px }
#server-status+* { margin-top:24px }
.reveal { transition:opacity var(--reveal-time) ease,transform var(--reveal-time) ease }
.reveal.pending { opacity:0;transform:translateY(16px) }
.reveal.shown { opacity:1;transform:none }
.skip { position:absolute;left:12px;top:-48px;z-index:80;padding:8px 14px;border-radius:var(--r-md);background:var(--text);color:var(--bg-panel);font-size:var(--size-small);text-decoration:none }
.skip:focus { top:8px }
.btn { display:inline-flex;align-items:center;justify-content:center;gap:8px;min-height:46px;padding:10px 22px;border:1px solid transparent;border-radius:var(--r-md);font-size:15px;font-weight:var(--weight-medium);line-height:24px;text-decoration:none;white-space:nowrap;flex-shrink:0;transition:transform var(--ease),background-color var(--ease),border-color var(--ease),box-shadow var(--ease) }
.btn--solid,.btn-primary { background:var(--text);color:var(--bg-panel);box-shadow:var(--shadow-button) }
.btn--solid:hover,.btn-primary:hover { transform:translateY(-1px);background:var(--accent-dark) }
.btn--line,.btn-secondary { background:var(--bg-panel);color:var(--text);border-color:rgb(var(--ink-rgb) / .28);box-shadow:inset 0 1px 0 rgb(var(--paper-rgb) / 1) }
.btn--line:hover,.btn-secondary:hover { transform:translateY(-1px);border-color:var(--text) }
.btn:active { transform:translateY(0) }
.btn:disabled,.btn[aria-disabled="true"] { color:var(--text-muted);background:var(--bg-panel-2);border-color:var(--border);box-shadow:none;cursor:not-allowed;transform:none }
.btn-row { display:flex;flex-wrap:wrap;align-items:center;gap:12px }
.notice { background:var(--mist-wash);border-bottom:1px solid var(--mist-line) }
.notice p { margin:0;min-height:36px;display:flex;align-items:center;justify-content:center;flex-wrap:wrap;gap:4px 12px;padding:6px 16px;font-size:13.5px;line-height:1.5;text-align:center }
.notice a { display:inline-flex;align-items:center;gap:6px;min-height:24px;color:var(--mist);font-weight:var(--weight-medium);text-decoration:none }
.notice a svg { width:16px;height:16px;transition:transform var(--ease) }
.notice a:hover svg { transform:translateX(3px) }
.topbar { position:relative;z-index:70;background:var(--hero-top);box-shadow:0 1px 0 rgb(var(--olive-rgb) / .10) }
.topbar__in { position:relative;height:60px;display:flex;align-items:center;gap:28px }
.brand { display:inline-flex;align-items:center;gap:10px;text-decoration:none;flex-shrink:0;min-height:28px }
.brand__mark { width:28px;height:28px;flex-shrink:0 }
.brand__en { font-family:var(--font-display);font-size:17px;font-weight:var(--weight-brand);letter-spacing:.03em;color:var(--text) }
.brand__zh { font-size:var(--size-small);font-weight:var(--weight-body);color:var(--text-muted) }
.mainnav ul { display:flex;align-items:center;list-style:none;margin:0;padding:0;gap:2px }
.mainnav a { display:inline-flex;align-items:center;justify-content:center;height:34px;padding:0 14px;border-radius:var(--r-pill);font-size:14.5px;color:var(--text-muted);text-decoration:none;white-space:nowrap;transition:color var(--ease),background-color var(--ease) }
.mainnav a:hover { color:var(--text);background:rgb(var(--olive-rgb) / .06) }
.mainnav a[aria-current="page"] { color:var(--accent-dark);background:rgb(var(--olive-rgb) / .12);font-weight:var(--weight-medium) }
.topbar__end { margin-left:auto;display:flex;align-items:center;gap:8px;flex-shrink:0 }
.language-control { position:relative }
.lang { display:inline-flex;align-items:center;justify-content:center;gap:6px;min-height:34px;min-width:44px;width:auto;padding:0 10px;border:0;border-radius:var(--r-md);background:transparent;color:var(--text-muted);font-size:var(--size-small);white-space:nowrap;transition:background-color var(--ease),color var(--ease) }
.lang span { white-space:nowrap }
.lang svg { width:16px;height:16px }
.lang:hover { background:rgb(var(--olive-rgb) / .06);color:var(--text) }
.language-menu { position:absolute;right:0;top:calc(100% + 8px);width:180px;margin:0;padding:8px;list-style:none;background:var(--bg-panel);border:1px solid var(--border);border-radius:var(--r-md);box-shadow:var(--shadow-chip) }
.language-menu a { display:flex;align-items:center;min-height:44px;padding:8px 12px;text-decoration:none;border-radius:var(--r-sm);color:var(--text) }
.language-menu a:hover,.language-menu a[aria-current] { background:var(--bg-panel-2) }
.btn-login { display:inline-flex;align-items:center;justify-content:center;height:36px;padding:0 18px;border-radius:var(--r-md);background:var(--text);color:var(--bg-panel);font-size:var(--size-small);font-weight:var(--weight-medium);text-decoration:none;white-space:nowrap;box-shadow:inset 0 1px 0 rgb(var(--paper-rgb) / .14),0 6px 16px -8px rgb(var(--ink-rgb) / .5);transition:background-color var(--ease) }
.btn-login:hover { background:var(--accent-dark) }
.menu-toggle { display:none;align-items:center;justify-content:center;min-width:44px;min-height:44px;padding:0;border:1px solid var(--border);border-radius:var(--r-md);background:var(--bg-panel);color:var(--text) }
.menu-toggle svg { width:20px;height:20px }
.mobile-drawer { position:absolute;top:100%;left:var(--gutter);right:var(--gutter);z-index:3;padding:12px;border:1px solid var(--border);border-radius:var(--r-card);background:var(--bg-panel);box-shadow:var(--shadow-chip);max-height:calc(100dvh - 112px);overflow-y:auto;overscroll-behavior:contain }
.mobile-drawer a { display:flex;align-items:center;width:100%;min-height:44px;padding:10px 14px;border-radius:var(--r-md);text-decoration:none;color:var(--text) }
.mobile-drawer a:hover,.mobile-drawer a[aria-current="page"] { background:var(--bg-panel-2);color:var(--accent-dark) }
.drawer-languages { border-top:1px solid var(--border);margin-top:12px;padding-top:12px }
.menu-veil { position:fixed;inset:0;z-index:65;border:0;background:rgb(var(--ink-rgb) / .28);cursor:default }
.site-footer { padding-top:56px;padding-bottom:32px;border-top:1px solid var(--border);background:var(--bg-panel-2) }
.footer-grid { display:grid;grid-template-columns:1.4fr 1fr 1.2fr 1fr;gap:40px }
.footer-grid>* { min-width:0 }
.footer-brand p { margin-top:16px;max-width:300px;color:var(--text-muted);font-size:var(--size-small) }
.footer-heading { margin:0 0 16px;font-size:var(--size-small);font-weight:var(--weight-medium) }
.footer-links { margin:0;padding:0;list-style:none }
.footer-links a { display:inline-flex;align-items:center;min-height:32px;padding-block:4px;font-size:var(--size-small);text-decoration:none;color:var(--text-muted);overflow-wrap:anywhere }
.footer-links a:hover { color:var(--text);text-decoration:underline }
.footer-bottom { display:flex;align-items:center;justify-content:space-between;flex-wrap:wrap;gap:12px;margin-top:40px;padding-top:20px;border-top:1px solid var(--border);font-size:13px;color:var(--text-muted) }
.footer-bottom p { margin:0 }
.footer-legal { display:flex;flex-wrap:wrap;gap:16px }
.footer-legal a { display:inline-flex;align-items:center;min-height:24px }
@media (max-width:1120px) {
  .topbar__in { gap:16px }
  .mainnav a { padding-inline:10px }
}
@media (max-width:960px) {
  .topbar__in { height:64px;gap:12px }
  .mainnav { display:none }
  .topbar__end { margin-left:auto }
  .menu-toggle { display:inline-flex }
  .footer-grid { grid-template-columns:repeat(2,minmax(0,1fr)) }
}
@media (max-width:768px) {
  :root { --gutter:16px;--section-space:48px;--size-h2:28px;--size-h3:20px }
  h1 { font-size:36px;line-height:1.2 }
  .grid { grid-template-columns:1fr }
  .panel { padding:24px }
}
@media (max-width:640px) {
  .no-break { white-space:normal }
  .tilt,[data-tilt] { transform:none }
  .decorated { max-width:100% }
  .footer-grid { gap:24px }
  .brand { gap:7px }
  .topbar__in { gap:8px }
  .topbar__end { gap:4px;margin-left:auto }
  .lang { padding-inline:6px }
  .btn-login { padding-inline:12px;min-height:44px }
}
@media (max-width:360px) {
  .brand__en { font-size:15px }
  .brand__mark { width:24px;height:24px }
  .lang { font-size:12px }
  .footer-grid { grid-template-columns:1fr }
}
@media (prefers-reduced-motion:reduce) {
  html { scroll-behavior:auto }
  *,*::before,*::after { transition-duration:0s!important }
  .reveal,.reveal.pending { opacity:1;transform:none }
}