:root {
  --bg:#FBFBFC;
  --panel:#FFFFFF;
  --panel-2:#F2F4F7;
  --line:#E3E6ED;
  --accent:#0B9FC7;
  --accent-2:#2DB8DC;
  --accent-dark:#0A6684;
  --ink:#161B2B;
  --ink-2:#262D42;
  --muted:#5A6273;
  --faint:#8A92A3;
  --success:#159E6A;
  --warn:#D4870F;
  --error:#D6433A;
  --clear:transparent;
  --accent-a04:rgba(11,159,199,.04);
  --accent-a06:rgba(11,159,199,.06);
  --accent-a08:rgba(11,159,199,.08);
  --accent-a10:rgba(11,159,199,.10);
  --accent-a12:rgba(11,159,199,.12);
  --accent-a18:rgba(11,159,199,.18);
  --ink-a04:rgba(22,27,43,.04);
  --ink-a05:rgba(22,27,43,.05);
  --ink-a06:rgba(22,27,43,.06);
  --ink-a08:rgba(22,27,43,.08);
  --ink-a12:rgba(22,27,43,.12);
  --white-a14:rgba(255,255,255,.14);
  --white-a40:rgba(255,255,255,.40);
  --white-a62:rgba(255,255,255,.62);
  --white-a80:rgba(255,255,255,.80);
  --white-a92:rgba(255,255,255,.92);
  --success-a16:rgba(21,158,106,.16);
  --tint-cyan:rgba(11,159,199,.15);
  --tint-mint:rgba(21,158,106,.15);
  --tint-butter:rgba(226,178,52,.17);
  --tint-peach:rgba(238,130,84,.15);
  --tint-slate:rgba(104,132,186,.15);
  --tint-sky:rgba(92,148,222,.17);
  --board-base:#F6F7FA;
  --spot-ice:rgba(142,186,242,.58);
  --spot-peach:rgba(246,166,114,.52);
  --spot-pink:rgba(238,172,206,.48);
  --spot-butter:rgba(247,221,142,.56);
  --chrome-dot:#D4D8E0;
  --flag-red:#D52B35;
  --flag-blue:#24438F;
  --flag-white:#FFFFFF;
  --font-display:'Inter','Noto Sans SC','Noto Sans JP','Noto Sans KR','PingFang SC','Hiragino Sans','Microsoft YaHei',system-ui,sans-serif;
  --font-body:'Inter','Noto Sans SC','Noto Sans JP','Noto Sans KR','PingFang SC','Hiragino Sans','Microsoft YaHei',system-ui,sans-serif;
  --font-mono:'JetBrains Mono',ui-monospace,'SFMono-Regular',Menlo,Consolas,monospace;
  --weight-regular:400;
  --weight-medium:500;
  --weight-semibold:600;
  --weight-bold:700;
  --weight-display:800;
  --text-xs:11px;
  --text-caption:12px;
  --text-small:13px;
  --text-label:14px;
  --text-nav:14.5px;
  --text-button:15.5px;
  --text-body:16px;
  --text-lede:17px;
  --text-brand:20px;
  --text-h3:24px;
  --text-connection:26px;
  --text-h2:clamp(28px,3vw,40px);
  --text-h1:clamp(52px,4.45vw,64px);
  --text-price:40px;
  --r-xl:32px;
  --r-card:28px;
  --r-lg:22px;
  --r-glass:20px;
  --r-float:18px;
  --r-mini:16px;
  --r-md:14px;
  --r-button:12px;
  --r-tab:13px;
  --r-sm:10px;
  --r-icon:9px;
  --r-focus:8px;
  --r-xs:6px;
  --r-node:4px;
  --r-mark:3px;
  --r-pill:999px;
  --r-circle:50%;
  --shadow-chip:0 1px 2px rgba(22,27,43,.05),0 4px 12px -6px rgba(11,159,199,.14);
  --shadow-btn:inset 0 1px 0 rgba(255,255,255,.14),0 8px 18px -8px rgba(22,27,43,.55);
  --shadow-ghost:0 1px 2px rgba(22,27,43,.05),0 6px 16px -10px rgba(11,159,199,.22);
  --shadow-shell:0 60px 110px -54px rgba(11,159,199,.26),0 24px 48px -34px rgba(22,27,43,.12);
  --shadow-glass:0 34px 80px -26px rgba(11,159,199,.12),0 12px 28px -18px rgba(11,159,199,.12);
  --shadow-float:0 16px 34px -14px rgba(38,86,108,.24),0 2px 6px -2px rgba(22,27,43,.06);
  --shadow-row:0 6px 18px -8px rgba(11,159,199,.22),0 1px 2px rgba(22,27,43,.05);
  --shadow-bubble:0 12px 26px -10px rgba(22,27,43,.5);
  --shadow-knob:0 2px 6px rgba(10,102,132,.35);
  --shadow-toggle:inset 0 1px 2px rgba(10,102,132,.25),0 4px 12px -4px rgba(11,159,199,.18);
  --shadow-panel:inset 0 1px 0 var(--panel),0 24px 64px -38px var(--accent-a12);
  --gutter:24px;
  --wrap-width:1280px;
  --reading-width:840px;
  --anchor-offset:96px;
  --toc-offset:16px;
  --toc-landing:104px;
  --ease-out:cubic-bezier(.2,.7,.2,1);
  --time-fast:150ms;
  --time-reveal:500ms;
}
*,*::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(--ink);font-family:var(--font-body);font-size:var(--text-body);line-height:1.6;-webkit-font-smoothing:antialiased;text-rendering:optimizeLegibility}
a{color:inherit;text-decoration:none}
button,input,select,textarea{font:inherit}
button{cursor:pointer;color:inherit;border:0;background:var(--clear)}
button:disabled{cursor:not-allowed}
img{display:block;max-width:100%;height:auto}
svg{flex-shrink:0;max-width:100%}
ul,ol{padding-left:1.5em}
p,figure{margin:0}
h1,h2,h3,h4{font-family:var(--font-display);color:var(--ink);text-wrap:balance;overflow-wrap:break-word}
h1{margin:0 0 22px;font-size:var(--text-h1);font-weight:var(--weight-display);line-height:1.1;letter-spacing:-.02em}
h2{margin:0 0 24px;font-size:var(--text-h2);font-weight:var(--weight-display);line-height:1.2;letter-spacing:-.02em}
h3{margin:0 0 16px;font-size:var(--text-h3);font-weight:var(--weight-bold);line-height:1.35}
:focus-visible{outline:2px solid var(--accent);outline-offset:3px;border-radius:var(--r-focus)}
[hidden]{display:none!important}
.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:64px;padding-bottom:64px}
.mono,code,pre{font-family:var(--font-mono)}
.mono{font-variant-numeric:tabular-nums}
.no-break{white-space:nowrap}
.muted{color:var(--muted)}
.kicker{display:block;margin-bottom:16px;color:var(--accent-dark);font-size:var(--text-small);font-weight:var(--weight-semibold)}
.prose{overflow-wrap:break-word}
.prose p,.prose ul,.prose ol,.prose pre,.prose blockquote{margin-bottom:24px}
.prose h2{margin-top:48px}
.prose h3{margin-top:32px}
.prose a:not(.btn){color:var(--accent-dark);text-decoration:underline;text-underline-offset:3px}
code{overflow-wrap:anywhere;font-size:.9em;background:var(--panel-2);border-radius:var(--r-xs);padding:2px 5px}
pre{max-width:100%;overflow-x:auto;padding:20px;border:1px solid var(--line);border-radius:var(--r-md);background:var(--panel-2)}
pre code{padding:0;white-space:pre;overflow-wrap:normal;background:var(--clear)}
.panel,.card{min-width:0;padding:28px;border:1px solid var(--line);border-radius:var(--r-card);background:var(--panel);box-shadow:var(--shadow-panel)}
.grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:24px}
.grid>*{min-width:0}
.decorated{position:relative;overflow-x:clip;max-width:100%}
.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;min-height:48px;padding:12px 22px;border-radius:var(--r-button);font-size:var(--text-button);font-weight:var(--weight-semibold);line-height:1.3;white-space:nowrap;flex-shrink:0;transition:background-color var(--time-fast),border-color var(--time-fast)}
.btn svg{width:16px;height:16px}
.btn-primary{background:var(--ink);color:var(--panel);box-shadow:var(--shadow-btn)}
.btn-primary:hover,.btn-primary.is-hover{background:var(--ink-2)}
.btn-ghost,.btn-secondary{background:var(--panel);color:var(--ink);border:1px solid var(--line);box-shadow:var(--shadow-ghost)}
.btn-ghost:hover,.btn-secondary:hover{border-color:var(--accent-a18)}
.btn:disabled,.btn[aria-disabled="true"]{opacity:.55;pointer-events:none}
.btn.is-focus{outline:2px solid var(--accent);outline-offset:3px}
.cta-row{display:flex;flex-wrap:wrap;justify-content:center;gap:12px;margin-bottom:20px}
.announce{display:flex;align-items:center;justify-content:center;gap:10px;height:36px;padding:0 20px;font-size:var(--text-small);font-weight:var(--weight-medium);line-height:1;color:var(--ink);background:repeating-linear-gradient(118deg,var(--accent-a08) 0 1px,var(--clear) 1px 10px),linear-gradient(90deg,var(--accent-a04),var(--accent-a12) 50%,var(--accent-a04));border-bottom:1px solid var(--line)}
.announce-sep{margin:0 8px;color:var(--accent-dark)}
.announce-arrow{color:var(--accent-dark);font-weight:var(--weight-semibold)}
.announce:hover .announce-text{text-decoration:underline;text-underline-offset:3px}
.topnav{position:relative;z-index:60;background:var(--white-a80);border-bottom:1px solid var(--line)}
.topnav-inner{position:relative;width:min(1280px,calc(100% - 40px));margin:0 auto;min-height:64px;display:flex;align-items:center;gap:24px;padding:0 20px}
.brand{display:inline-flex;align-items:center;gap:10px;font-family:var(--font-display);font-weight:var(--weight-display);font-size:var(--text-brand);letter-spacing:-.02em;line-height:1;color:var(--ink);min-height:44px;flex-shrink:0}
.brand-mark{width:28px;height:28px;display:block}
.brand-zh{font-size:var(--text-label);font-weight:var(--weight-medium);color:var(--muted)}
.desktop-nav{flex:1;min-width:0}
.nav-list{flex:1;display:flex;align-items:center;justify-content:center;gap:2px;list-style:none;margin:0;padding:0}
.nav-list a{display:inline-flex;align-items:center;justify-content:center;height:36px;padding:0 14px;border-radius:var(--r-pill);font-size:var(--text-nav);font-weight:var(--weight-medium);line-height:1;color:var(--muted);white-space:nowrap;transition:color var(--time-fast),background-color var(--time-fast)}
.nav-list a:hover{color:var(--ink);background:var(--ink-a04)}
.nav-list a[aria-current="page"]{color:var(--accent-dark);font-weight:var(--weight-semibold);background:var(--accent-a10)}
.nav-side{display:flex;align-items:center;gap:8px;flex-shrink:0}
.lang-box{position:relative}
.lang{display:inline-flex;align-items:center;justify-content:center;gap:6px;min-height:36px;width:auto;padding:0 10px;border-radius:var(--r-sm);font-size:var(--text-label);line-height:1;color:var(--muted);white-space:nowrap}
.lang span{white-space:nowrap}
.lang:hover{color:var(--ink);background:var(--ink-a04)}
.lang svg{width:16px;height:16px}
.lang-menu{position:absolute;right:0;top:calc(100% + 10px);width:180px;padding:8px;background:var(--panel);border:1px solid var(--line);border-radius:var(--r-md);box-shadow:var(--shadow-float)}
.lang-menu a{display:flex;align-items:center;min-height:44px;padding:8px 12px;border-radius:var(--r-sm);font-size:var(--text-label)}
.lang-menu a:hover,.lang-menu a[aria-current="true"]{background:var(--accent-a10);color:var(--accent-dark)}
.login{display:inline-flex;align-items:center;justify-content:center;gap:6px;min-height:38px;padding:8px 14px 8px 16px;border-radius:var(--r-button);background:var(--panel);border:1px solid var(--line);font-size:var(--text-label);font-weight:var(--weight-semibold);line-height:1;color:var(--ink);white-space:nowrap;box-shadow:var(--shadow-ghost)}
.login svg{width:14px;height:14px;color:var(--muted)}
.login:hover{border-color:var(--accent-a18)}
.menu-toggle{display:none;align-items:center;justify-content:center;min-width:44px;min-height:44px;border:1px solid var(--line);border-radius:var(--r-button);background:var(--panel)}
.menu-toggle svg{width:20px;height:20px}
.mobile-drawer{position:absolute;top:100%;left:0;right:0;z-index:62;padding:16px 24px 24px;background:var(--panel);border-bottom:1px solid var(--line);max-height:calc(100dvh - 100px);overflow-y:auto;overscroll-behavior:contain}
.mobile-drawer a{display:flex;align-items:center;width:100%;min-height:44px;padding:12px 16px;border-radius:var(--r-button);color:var(--ink)}
.mobile-drawer a[aria-current]{background:var(--accent-a10);color:var(--accent-dark)}
.drawer-languages{margin-top:16px;padding-top:16px;border-top:1px solid var(--line)}
.nav-veil{position:fixed;inset:0;z-index:55;background:var(--ink-a12)}
.site-footer{border-top:1px solid var(--line);background:linear-gradient(180deg,var(--accent-a04),var(--bg));padding-top:48px;padding-bottom:24px}
.footer-grid{display:grid;grid-template-columns:1.3fr 1fr 1fr 1fr;gap:32px}
.footer-grid>*{min-width:0}
.footer-brand p{margin-top:20px;max-width:320px;color:var(--muted);font-size:var(--text-label)}
.footer-title{font-size:var(--text-label);font-weight:var(--weight-bold);margin:0 0 12px}
.footer-links{display:flex;flex-direction:column;gap:4px;list-style:none;margin:0;padding:0}
.footer-links a{display:inline-flex;align-items:center;min-height:32px;color:var(--muted);font-size:var(--text-label);overflow-wrap:anywhere}
.footer-links a:hover{color:var(--accent-dark)}
.footer-bottom{display:flex;align-items:center;justify-content:space-between;flex-wrap:wrap;gap:12px;margin-top:36px;padding-top:20px;border-top:1px solid var(--line);color:var(--muted);font-size:var(--text-small)}
.footer-legal{display:flex;flex-wrap:wrap;gap:20px}
.footer-legal a{display:inline-flex;align-items:center;min-height:28px}
.reveal{transition:opacity var(--time-reveal) var(--ease-out),transform var(--time-reveal) var(--ease-out)}
.reveal.pending{opacity:0;transform:translateY(16px)}
.reveal.shown{opacity:1;transform:none}
#server-status{position:relative;display:block;min-height:120px;max-width:100%;overflow:hidden;margin-top:24px;margin-bottom:32px}
#server-status>*{min-width:0;max-width:100%}
#server-status+*{margin-top:24px}
@media(max-width:1180px){
  .topnav-inner{gap:14px}
  .nav-list a{padding-inline:10px;font-size:var(--text-label)}
}
@media(max-width:960px){
  .topnav-inner{padding:10px 16px;min-height:64px}
  .desktop-nav{display:none}
  .nav-side{margin-left:auto}
  .menu-toggle{display:inline-flex}
  .footer-grid{grid-template-columns:repeat(2,minmax(0,1fr))}
}
@media(max-width:768px){
  :root{--gutter:20px}
  h1{font-size:40px;line-height:1.15}
  .announce{font-size:var(--text-caption);height:auto;min-height:36px;padding:8px 14px;text-align:center;line-height:1.4}
  .grid{grid-template-columns:1fr}
  .sec{padding-top:40px;padding-bottom:40px}
}
@media(max-width:640px){
  :root{--gutter:16px}
  .no-break{white-space:normal}
  .tilt,.decorative-tilt{transform:none}
  .decorated{max-width:100%;overflow-x:clip}
  .topnav-inner{width:100%;padding-inline:16px;gap:8px}
  .brand{gap:6px;font-size:var(--text-lede)}
  .brand-mark{width:24px;height:24px}
  .nav-side{margin-left:auto;gap:4px}
  .lang{padding-inline:6px;font-size:var(--text-caption);min-width:44px}
  .login{padding-inline:10px}
  .login svg{display:none}
  .footer-grid{grid-template-columns:1fr;gap:24px}
  .panel,.card{padding:20px}
  .btn{padding-inline:18px;max-width:100%}
}
@media(prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  .reveal,.reveal.pending,.reveal.shown{opacity:1;transform:none;transition:none}
  *,*::before,*::after{transition-duration:0s!important;animation-duration:0s!important}
}