:root{
  --bg:#E6F0F3;--bg-top:#EEF5F7;--bg-bottom:#DCEAEE;
  --panel:#F6FAFB;--panel-2:#D6E6EB;--sunk:#EEF4F6;--surface:#FFFFFF;--fog:#D9EAEF;
  --border:#C5D9DF;--border-soft:#DCE8EC;
  --accent:#00788C;--accent-dark:#005463;--accent-2:#3FB8C4;
  --ink:#0F2A33;--text:#0F2229;--muted:#4C6570;--muted-2:#6C848E;
  --success:#1F8A55;--warn:#B9750F;--error:#C2413A;
  --accent-a04:rgba(0,120,140,.04);--accent-a06:rgba(0,120,140,.06);
  --accent-a08:rgba(0,120,140,.08);--accent-a12:rgba(0,120,140,.12);
  --accent-a18:rgba(0,120,140,.18);--accent-a28:rgba(0,120,140,.28);
  --success-a12:rgba(31,138,85,.12);--success-a16:rgba(31,138,85,.16);--warn-a16:rgba(185,117,15,.16);
  --white-a0:rgba(255,255,255,0);--white-a28:rgba(255,255,255,.28);--white-a72:rgba(255,255,255,.72);
  --knob-shade:rgba(0,84,99,.35);--dot-edge:rgba(15,34,41,.14);--veil:rgba(15,42,51,.28);
  --dot-close:#EC6A5E;--dot-min:#F3BE4F;--dot-max:#61C554;
  --flag-red:#D52B35;--flag-blue:#2C4D9C;--flag-navy:#243A73;--flag-green:#2B8B4D;--flag-white:#FFFFFF;--flag-edge:rgba(15,34,41,.14);
  --r-xs:6px;--r-sm:8px;--r-md:12px;--r-lg:14px;--r-icon:10px;--r-tape:3px;--r-circle:50%;--r-pill:999px;
  --font-display:"Inter","Noto Sans SC","PingFang SC","Hiragino Sans","Microsoft YaHei","Apple SD Gothic Neo","Malgun Gothic",system-ui,sans-serif;
  --font-body:"Inter","Noto Sans SC","PingFang SC","Hiragino Sans","Microsoft YaHei","Apple SD Gothic Neo","Malgun Gothic",system-ui,sans-serif;
  --font-mono:"JetBrains Mono",ui-monospace,"SFMono-Regular",Menlo,Consolas,monospace;
  --fs-body:16px;--fs-small:14px;--fs-caption:12px;--fs-display:66px;--fs-h2:36px;--fs-h3:23px;
  --weight-regular:400;--weight-medium:500;--weight-semibold:600;--weight-bold:700;--weight-heavy:800;--weight-display:900;
  --gutter:24px;--content:1200px;--reading:780px;--section-space:72px;
  --head-height:64px;--announcement-height:36px;--header-total:100px;--anchor-offset:116px;--toc-offset:88px;
  --shadow-panel:0 40px 90px var(--accent-a12);
  --shadow-raise:0 1px 2px var(--accent-a12),0 4px 12px var(--accent-a08);
  --shadow-float:0 12px 30px var(--accent-a18),0 2px 6px var(--accent-a08);
  --shadow-cta:0 8px 22px var(--accent-a28),inset 0 1px 0 var(--white-a28);
  --shadow-cta-hover:0 12px 28px var(--accent-a28),inset 0 1px 0 var(--white-a28);
  --ease:ease;--fast:.18s;--reveal-time:.35s;
}
*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth;scroll-padding-top:var(--anchor-offset)}
body{margin:0;background:var(--bg);color:var(--text);font-family:var(--font-body);font-size:var(--fs-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}
button,a,input,summary,select,textarea{-webkit-tap-highlight-color:var(--accent-a12)}
button{color:inherit}
img{display:block;max-width:100%;height:auto}
svg{flex-shrink:0;vertical-align:middle}
button svg,a svg{width:18px;height:18px}
ul,ol{padding-left:1.5em}
p{margin:0 0 1em}
h1,h2,h3{font-family:var(--font-display);line-height:1.2;text-wrap:balance}
h1{font-size:clamp(52px,5vw,72px);font-weight:var(--weight-display);letter-spacing:-.02em;margin:0 0 24px}
h2{font-size:var(--fs-h2);font-weight:var(--weight-heavy);letter-spacing:-.02em;margin:0 0 24px}
h3{font-size:var(--fs-h3);font-weight:var(--weight-bold);margin:0 0 16px}
h1,h2,h3,p,li{overflow-wrap:break-word}
hr{border:0;border-top:1px solid var(--border);margin:32px 0}
[hidden]{display:none!important}
:focus-visible{outline:2px solid var(--accent);outline-offset:3px}
.wrap{width:100%;max-width:calc(var(--content) + var(--gutter)*2);margin-inline:auto;padding-inline:var(--gutter)}
.reading-wrap{width:100%;max-width:calc(var(--reading) + var(--gutter)*2);margin-inline:auto;padding-inline:var(--gutter)}
.sec{padding-top:var(--section-space);padding-bottom:var(--section-space)}
.grid{display:grid;gap:24px}
.grid>*{min-width:0}
.grid-3{grid-template-columns:repeat(3,minmax(0,1fr))}
.flex-row{display:flex;align-items:center;flex-wrap:wrap;gap:12px}
.mono,code,pre{font-family:var(--font-mono)}
code{overflow-wrap:anywhere;font-size:.9em}
pre{max-width:100%;overflow-x:auto;padding:24px;border-radius:var(--r-md);background:var(--sunk);border:1px solid var(--border);line-height:1.7}
pre code{overflow-wrap:normal;white-space:pre}
.prose{min-width:0;line-height:1.85}
.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}
.prose li{margin-bottom:8px}
.muted{color:var(--muted)}
.no-break{white-space:nowrap}
.sr{position:absolute;width:1px;height:1px;margin:-1px;padding:0;border:0;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap}
.sprite{position:absolute;width:0;height:0;overflow:hidden}
.skip{position:absolute;left:16px;top:-56px;z-index:100;padding:10px 16px;border-radius:var(--r-sm);background:var(--ink);color:var(--surface);font-size:var(--fs-small);font-weight:var(--weight-semibold)}
.skip:focus{top:12px}
.panel,.card{min-width:0;padding:28px;border:1px solid var(--border);border-radius:var(--r-lg);background:var(--panel);box-shadow:var(--shadow-raise),inset 0 1px 0 var(--surface)}
.panel-sunk{background:var(--panel-2);box-shadow:inset 0 1px 2px var(--accent-a12)}
.decorated{position:relative;overflow-x:clip;max-width:100%}
.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;min-height:44px;padding:12px 22px;border:0;border-radius:var(--r-pill);font-weight:var(--weight-bold);line-height:1;white-space:nowrap;flex-shrink:0;transition:transform var(--fast) var(--ease),box-shadow var(--fast) var(--ease),background-color var(--fast) var(--ease)}
.btn svg{transition:transform var(--fast) var(--ease)}
.btn-primary{color:var(--surface);background:linear-gradient(135deg,var(--accent) 0%,var(--accent) 42%,var(--accent-2) 150%);box-shadow:var(--shadow-cta)}
.btn-primary:hover{transform:translateY(-1px);box-shadow:var(--shadow-cta-hover)}
.btn-primary:hover svg{transform:translateX(2px)}
.btn-ghost,.btn-secondary{color:var(--text);background:var(--white-a72);box-shadow:inset 0 0 0 1px var(--border)}
.btn-ghost:hover,.btn-secondary:hover{background:var(--surface)}
.btn-sm{height:36px;min-height:36px;padding:0 16px;font-size:var(--fs-small)}
.btn-sm svg{width:15px;height:15px}
.btn-lg{height:50px;padding:0 28px;font-size:17px}
.btn:active{transform:translateY(0)}
.btn:disabled,.btn[aria-disabled="true"]{opacity:.55;cursor:not-allowed;box-shadow:none;transform:none}
.annc{background:var(--fog);border-bottom:1px solid var(--border-soft)}
.annc a{display:flex;align-items:center;justify-content:center;gap:10px;min-height:var(--announcement-height);padding:6px 16px;font-size:var(--fs-small);line-height:20px;font-weight:var(--weight-medium)}
.annc-tag{display:inline-flex;align-items:center;height:20px;padding:0 9px;border-radius:var(--r-pill);background:var(--accent);color:var(--surface);font-size:var(--fs-caption);font-weight:var(--weight-bold);letter-spacing:.06em;line-height:1;flex-shrink:0}
.annc-arrow{color:var(--accent);font-weight:var(--weight-bold)}
#site-header{position:relative;z-index:60}
.site-head{position:relative;z-index:63;background:var(--bg-top)}
.head-in{width:min(var(--content),100% - 48px);margin:0 auto;height:var(--head-height);display:flex;align-items:center;gap:28px;flex-wrap:nowrap}
.brand{display:inline-flex;align-items:center;gap:10px;font-family:var(--font-display);font-weight:var(--weight-heavy);font-size:19px;line-height:1;letter-spacing:-.02em;flex-shrink:0}
.brand-zh{font-size:var(--fs-small);font-weight:var(--weight-medium);color:var(--muted)}
.mark{width:30px;height:30px;border-radius:var(--r-circle);flex-shrink:0;display:inline-block}
.mark-xs{width:20px;height:20px}
.nav{flex:1;min-width:0;display:flex;justify-content:center}
.nav ul{display:flex;align-items:center;list-style:none;margin:0;padding:0;gap:2px}
.nav a{display:inline-flex;align-items:center;gap:7px;min-height:36px;padding:0 12px;border-radius:var(--r-pill);font-size:15px;line-height:1.25;font-weight:var(--weight-medium);color:var(--muted);white-space:nowrap}
.nav a svg{width:16px;height:16px}
.nav a:hover{color:var(--text);background:var(--white-a72)}
.nav a[aria-current="page"]{color:var(--text);font-weight:var(--weight-semibold)}
.nav a[aria-current="page"] svg{color:var(--accent)}
.tools{display:flex;align-items:center;gap:8px;flex-shrink:0}
.language{position:relative}
.lang{display:inline-flex;align-items:center;justify-content:center;gap:6px;min-width:44px;width:auto;min-height:36px;padding:0 10px;border:0;border-radius:var(--r-pill);background:transparent;color:var(--muted);font-size:var(--fs-small);line-height:1.2}
.lang span{white-space:nowrap}
.lang svg{width:15px;height:15px}
.lang:hover{color:var(--text);background:var(--white-a72)}
.lang-panel{position:absolute;z-index:80;right:0;top:calc(100% + 8px);min-width:180px;padding:8px;border:1px solid var(--border);border-radius:var(--r-md);background:var(--panel);box-shadow:var(--shadow-float)}
.lang-panel a{display:flex;align-items:center;min-height:44px;padding:8px 12px;border-radius:var(--r-sm);font-size:var(--fs-small)}
.lang-panel a:hover,.lang-panel a[aria-current="true"]{background:var(--panel-2);color:var(--accent-dark)}
.menu-toggle{display:none;align-items:center;justify-content:center;min-width:44px;min-height:44px;border:0;border-radius:var(--r-sm);background:transparent;color:var(--text)}
.menu-toggle svg{width:22px;height:22px}
.menu-drawer{display:none}
.menu-veil{display:none}
html.nav-open{overflow:hidden}
.site-foot{border-top:1px solid var(--border);background:var(--sunk);padding-top:56px;padding-bottom:24px}
.foot-grid{display:grid;grid-template-columns:1.4fr 1fr 1fr;gap:40px}
.foot-brand p{max-width:340px;margin-top:20px;color:var(--muted);font-size:var(--fs-small)}
.foot-title{margin:0 0 16px;font-size:var(--fs-small);font-weight:var(--weight-bold)}
.foot-links{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:6px 16px;list-style:none;margin:0;padding:0}
.foot-links a,.foot-languages a,.foot-legal a{display:inline-flex;align-items:center;min-height:28px;font-size:var(--fs-small);color:var(--muted)}
.foot-links a:hover,.foot-languages a:hover,.foot-legal a:hover{color:var(--accent-dark);text-decoration:underline}
.foot-languages{display:flex;flex-wrap:wrap;gap:8px 20px;margin-top:32px}
.foot-bottom{display:flex;align-items:center;justify-content:space-between;gap:16px;flex-wrap:wrap;border-top:1px solid var(--border);margin-top:24px;padding-top:24px;color:var(--muted);font-size:var(--fs-caption)}
.foot-bottom p{margin:0}
.foot-legal{display:flex;flex-wrap:wrap;gap:16px}
.reveal{transition:opacity var(--reveal-time) var(--ease),transform var(--reveal-time) var(--ease)}
.reveal.pending{opacity:0;transform:translateY(16px)}
.reveal.shown{opacity:1;transform:none}
#server-status{display:block;position:relative;min-width:0;max-width:100%;min-height:120px;overflow:hidden;margin-top:24px;margin-bottom:24px}
#server-status>*{min-width:0;max-width:100%}
#server-status+*{margin-top:24px}
@media(min-width:769px) and (max-width:1190px){
  .head-in{gap:12px}
  .nav a{padding-inline:8px;font-size:var(--fs-small);gap:5px}
  .tools{gap:4px}
  .lang{padding-inline:6px;font-size:var(--fs-caption)}
}
@media(max-width:1000px){
  .foot-grid{gap:24px}
}
@media(max-width:768px){
  :root{--gutter:20px;--section-space:48px;--head-height:58px;--header-total:94px;--anchor-offset:110px;--fs-h2:28px;--fs-h3:21px}
  h1{font-size:38px;line-height:1.15}
  .head-in{width:calc(100% - 32px);gap:8px;justify-content:space-between}
  .brand{font-size:17px;gap:7px}
  .brand .mark{width:27px;height:27px}
  .nav{display:none}
  .tools{margin-left:auto;gap:3px}
  .tools .btn-sm{padding-inline:12px}
  .lang{padding-inline:5px;font-size:var(--fs-caption);gap:3px}
  .lang svg{display:none}
  .menu-toggle{display:inline-flex}
  .menu-drawer{position:fixed;z-index:62;top:var(--header-total);left:0;right:0;height:calc(100dvh - var(--header-total));max-height:calc(100dvh - var(--header-total));overflow-y:auto;overscroll-behavior:contain;padding:20px var(--gutter) 36px;background:var(--panel);border-top:1px solid var(--border)}
  .menu-drawer:not([hidden]){display:block}
  .menu-drawer a{display:flex;align-items:center;gap:12px;width:100%;min-height:48px;padding:12px 16px;border-radius:var(--r-sm);font-weight:var(--weight-medium)}
  .menu-drawer a:hover,.menu-drawer a[aria-current="page"]{background:var(--panel-2);color:var(--accent-dark)}
  .drawer-languages{margin-top:20px;padding-top:16px;border-top:1px solid var(--border)}
  .menu-veil{position:fixed;z-index:61;top:var(--header-total);bottom:0;left:0;right:0;border:0;background:var(--veil);width:100%}
  .menu-veil:not([hidden]){display:block}
  .grid-3{grid-template-columns:minmax(0,1fr)}
  .foot-grid{grid-template-columns:minmax(0,1fr) minmax(0,1fr)}
  .foot-brand{grid-column:1/-1}
}
@media(max-width:640px){
  :root{--gutter:16px}
  .no-break{white-space:normal}
  .tilt,.note{transform:none}
  .decorated{max-width:100%;overflow-x:clip}
  .panel,.card{padding:20px}
  .foot-grid{grid-template-columns:minmax(0,1fr)}
  .foot-brand{grid-column:auto}
  .foot-bottom{align-items:flex-start;flex-direction:column}
}
@media(prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  *,*::before,*::after{animation-duration:0s!important;transition-duration:0s!important}
  .reveal,.reveal.pending{opacity:1;transform:none}
}