:root{
  --bg:#ECEBF8;--bg-top:#F4F3FC;--bg-bottom:#E4E3F4;--panel:#F8F8FE;--panel-2:#E0DFF2;--border:#D3D2EA;--border-soft:#E4E3F2;--white:#FFFFFF;
  --accent:#18A8D8;--accent-ink:#1190BF;--accent-dark:#0A6F93;--accent-mate:#4C7BEA;--canvas-end:#C9CCF2;
  --text:#161830;--muted:#5A5C78;--ink-text-soft:#C3C5E0;--on-ink:#F8F8FE;--success:#1F9D61;--warn:#C98A0B;--error:#D43B4B;
  --accent-a04:rgba(24,168,216,.04);--accent-a12:rgba(24,168,216,.12);--accent-a22:rgba(24,168,216,.22);--accent-a35:rgba(24,168,216,.35);
  --ink-a06:rgba(22,24,48,.06);--ink-a14:rgba(22,24,48,.14);--ink-a24:rgba(22,24,48,.24);--veil:rgba(22,24,48,.36);
  --white-a00:rgba(255,255,255,0);--white-a16:rgba(255,255,255,.16);--white-a35:rgba(255,255,255,.35);--white-a55:rgba(255,255,255,.55);--white-a90:rgba(255,255,255,.9);
  --success-a12:rgba(31,157,97,.12);--success-a28:rgba(31,157,97,.28);--dot-grid:rgba(255,255,255,.04);
  --flag-red:#D6283C;--flag-blue:#2A3F8F;--flag-white:#FFFFFF;--flag-green:#13955A;--flag-edge:rgba(22,24,48,.12);
  --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;
  --r-xl:32px;--r-window:24px;--r-card:18px;--r-btn:14px;--r-nav:12px;--r-sm:10px;--r-tag:6px;--r-pill:999px;--r-round:50%;
  --shadow-card:0 24px 60px -16px var(--accent-a35),0 6px 16px -8px var(--ink-a14);
  --shadow-soft:0 18px 48px -18px var(--accent-a35);--shadow-panel:0 24px 64px -20px var(--accent-a12),inset 0 1px 0 var(--white-a90);
  --gutter:48px;--wrap-max:1408px;--section-space:80px;--anchor-space:112px;--toc-space:104px;
  --size-display:64px;--size-h2:40px;--size-h3:24px;--size-body:16px;--size-small:14px;--weight-display:800;--ease: .2s ease;
}
*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-padding-top:var(--anchor-space);scroll-behavior:smooth}
body{margin:0;background:var(--bg);color:var(--text);font-family:var(--font-body);font-size:var(--size-body);line-height:1.6;-webkit-font-smoothing:antialiased;text-rendering:optimizeLegibility}
html.nav-open{overflow:hidden}
[hidden]{display:none!important}
a{color:inherit;text-decoration:none}
button,input,select,textarea{font:inherit;color:inherit}
button{cursor:pointer}
img{display:block;max-width:100%;height:auto}
svg{flex-shrink:0}
h1,h2,h3,h4,p{margin:0}
h1{font-family:var(--font-display);font-size:var(--size-display);font-weight:var(--weight-display);line-height:1.1;letter-spacing:-.02em;text-wrap:balance}
h2{font-family:var(--font-display);font-size:var(--size-h2);font-weight:var(--weight-display);line-height:1.2;letter-spacing:-.02em;text-wrap:balance}
h3{font-size:var(--size-h3);line-height:1.35}
ul,ol{padding-left:1.5em}
pre{max-width:100%;overflow-x:auto;padding:24px;border-radius:var(--r-card);background:var(--text);color:var(--on-ink)}
code{font-family:var(--font-mono);overflow-wrap:anywhere}
pre code{overflow-wrap:normal;white-space:pre}
table{border-collapse:collapse}
th,td{word-break:keep-all}
:focus-visible{outline:2px solid var(--accent-dark);outline-offset:3px}
.sr-only{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-max);padding-inline:var(--gutter);margin-inline:auto}
.section{padding-top:var(--section-space);padding-bottom:var(--section-space)}
.no-break{white-space:nowrap}
.muted{color:var(--muted)}
.accent{color:var(--accent-dark)}
.mono{font-family:var(--font-mono)}
.panel,.card{min-width:0;background:var(--panel);box-shadow:var(--shadow-panel);border:1px solid var(--white-a90)}
.panel{padding:40px;border-radius:var(--r-xl)}
.card{padding:28px;border-radius:var(--r-card)}
.grid{display:grid;gap:24px}
.grid > *,.hero-grid > *{min-width:0}
.grid-three{grid-template-columns:repeat(3,minmax(0,1fr))}
.grid-five{grid-template-columns:repeat(5,minmax(0,1fr))}
.section-head{max-width:760px;margin:0 auto 40px;text-align:center}
.section-head p{margin-top:16px;color:var(--muted)}
.section-head .btn-ghost{margin-top:24px}
.btn,.btn-primary,.btn-ghost,.btn-secondary{display:inline-flex;align-items:center;justify-content:center;gap:8px;flex-shrink:0;min-height:48px;padding:0 20px;border-radius:var(--r-btn);font-size:15.5px;font-weight:700;white-space:nowrap;text-align:center;transition:background-color var(--ease),transform var(--ease),box-shadow var(--ease)}
.btn-primary{border:0;background:linear-gradient(135deg,var(--accent) 0%,var(--accent) 50%,var(--accent-mate) 150%);color:var(--text);box-shadow:inset 0 1px 0 var(--white-a55),0 10px 22px -10px var(--accent-a35)}
.btn-primary:hover{transform:translateY(-1px);box-shadow:inset 0 1px 0 var(--white-a55),0 14px 26px -10px var(--accent-a35)}
.btn-primary:active{transform:translateY(0)}
.btn-ghost,.btn-secondary{height:60px;padding-inline:26px;border:1.5px solid var(--text);background:var(--white-a00);color:var(--text)}
.btn-ghost:hover,.btn-secondary:hover{background:var(--panel)}
button:disabled,.btn[aria-disabled="true"]{opacity:.55;cursor:not-allowed;transform:none}
.btn-primary svg,.btn svg{width:18px;height:18px;fill:none;stroke:currentColor;stroke-width:2.2;stroke-linecap:round;stroke-linejoin:round}
.announce{background:var(--text);color:var(--ink-text-soft);font-size:13.5px;line-height:1.5}
.announce-in{display:flex;align-items:center;justify-content:center;gap:28px;min-height:40px;padding-top:8px;padding-bottom:8px}
.announce-text{display:flex;flex-wrap:wrap;justify-content:center;gap:4px 18px}
.announce-tag{color:var(--accent);font-weight:700;letter-spacing:.02em}
.announce-link{display:inline-flex;align-items:center;min-height:24px;color:var(--on-ink);font-weight:600;text-decoration:underline;text-underline-offset:5px;white-space:nowrap}
.announce-link:hover{color:var(--accent)}
#site-header{position:relative;z-index:60}
.site-head{position:relative;z-index:63;background:var(--bg-top);border-bottom:1px solid var(--border-soft)}
.head-in{display:flex;align-items:center;gap:24px;min-height:72px}
.brand{display:inline-flex;align-items:center;gap:10px;flex:none;min-height:44px}
.brand-mark{display:block;width:34px;height:34px;flex:none}
.brand-en{font-family:var(--font-display);font-size:20px;font-weight:800;letter-spacing:-.02em;line-height:1}
.main-nav{flex:1;min-width:0;display:flex;justify-content:flex-start;overflow-x:auto;scrollbar-width:thin}
.main-nav ul{display:flex;flex-shrink:0;flex-wrap:nowrap;align-items:center;justify-content:center;list-style:none;margin:0 auto;padding:0;gap:2px}
.main-nav a{display:inline-flex;align-items:center;gap:6px;padding:8px 10px;min-height:40px;border-radius:var(--r-nav);font-size:14px;font-weight:500;color:var(--muted);white-space:nowrap;transition:background-color var(--ease),color var(--ease)}
.main-nav svg,.nav-drawer svg{display:block;width:16px;height:16px;fill:none;stroke:currentColor;stroke-width:1.8;stroke-linecap:round;stroke-linejoin:round}
.main-nav a:hover{color:var(--text);background:var(--panel-2)}
.main-nav a[aria-current="page"]{color:var(--text);background:var(--panel);box-shadow:inset 0 0 0 1px var(--border-soft),0 6px 16px -10px var(--accent-a35)}
.main-nav a[aria-current="page"] svg{color:var(--accent-dark)}
.head-tools{display:flex;align-items:center;gap:10px;flex-shrink:0}
.lang-wrap{position:relative}
.lang{display:inline-flex;align-items:center;justify-content:center;gap:6px;min-width:44px;width:auto;height:40px;padding:0 12px;border:0;border-radius:var(--r-nav);background:var(--white-a00);font-size:14px;font-weight:500;color:var(--muted);white-space:nowrap}
.lang span{white-space:nowrap}
.lang:hover{background:var(--panel-2);color:var(--text)}
.lang svg,.login svg{display:block;width:16px;height:16px;fill:none;stroke:currentColor;stroke-width:1.8;stroke-linecap:round;stroke-linejoin:round}
.lang-panel{position:absolute;right:0;top:calc(100% + 8px);z-index:80;width:184px;padding:8px;border-radius:var(--r-card);background:var(--panel);border:1px solid var(--border);box-shadow:var(--shadow-card)}
.lang-panel a{display:flex;align-items:center;min-height:44px;padding:8px 12px;border-radius:var(--r-sm)}
.lang-panel a:hover,.lang-panel a[aria-current="true"]{background:var(--panel-2);color:var(--accent-dark)}
.login{display:inline-flex;align-items:center;justify-content:center;gap:8px;height:40px;padding:0 18px;border-radius:var(--r-btn);background:var(--text);color:var(--on-ink);font-size:14px;font-weight:600;white-space:nowrap;box-shadow:0 10px 22px -14px var(--ink-a24)}
.login:hover{background:var(--accent-dark)}
.nav-toggle{display:none;align-items:center;justify-content:center;flex-direction:column;gap:4px;min-width:44px;min-height:44px;border:1px solid var(--border);border-radius:var(--r-sm);background:var(--panel);color:var(--text)}
.nav-line{display:block;width:20px;height:2px;background:currentColor}
.nav-drawer{position:absolute;top:100%;left:0;right:0;z-index:62;height:calc(100dvh - 140px);max-height:calc(100dvh - 140px);padding:16px var(--gutter) 32px;overflow-y:auto;overscroll-behavior:contain;background:var(--panel);border-top:1px solid var(--border)}
.nav-drawer a{display:flex;align-items:center;gap:12px;width:100%;min-height:48px;padding:12px;border-radius:var(--r-sm)}
.nav-drawer a:hover,.nav-drawer a[aria-current="page"]{background:var(--panel-2)}
.drawer-languages{border-top:1px solid var(--border);margin-top:16px;padding-top:12px}
.nav-veil{position:absolute;top:100%;left:0;right:0;height:100dvh;z-index:61;background:var(--veil);border:0}
.site-foot{background:var(--panel-2);border-top:1px solid var(--border);padding-top:56px;padding-bottom:24px}
.foot-grid{display:grid;grid-template-columns:minmax(0,1.3fr) minmax(0,1fr) minmax(0,1fr);gap:48px}
.foot-brand p{max-width:380px;margin-top:18px;color:var(--muted)}
.foot-title{font-size:16px;font-weight:700;margin-bottom:12px}
.foot-links{list-style:none;padding:0;margin:0;display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:4px 18px}
.foot-links a,.foot-languages a,.foot-legal a{display:inline-flex;align-items:center;min-height:32px;color:var(--muted);font-size:14px}
.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 24px;margin-top:32px;padding-top:24px;border-top:1px solid var(--border)}
.foot-bottom{display:flex;align-items:center;justify-content:space-between;flex-wrap:wrap;gap:12px;margin-top:18px;color:var(--muted);font-size:13px}
.foot-legal{display:flex;flex-wrap:wrap;gap:20px}
.prose{max-width:880px;margin-inline:auto;overflow-wrap:break-word}
.prose p,.prose ul,.prose ol,.prose blockquote{margin-top:20px}
.prose h2{margin-top:48px;font-size:32px}
.prose h3{margin-top:32px}
.prose a{color:var(--accent-dark);text-decoration:underline;text-underline-offset:3px}
.prose li + li{margin-top:8px}
.reveal{transition:opacity .35s ease,transform .35s ease}
.reveal.pending{opacity:0;transform:translateY(16px)}
.reveal.shown{opacity:1;transform:none}
#server-status{position:relative;display:block;min-width:0;min-height:120px;max-width:100%;overflow:hidden;margin-top:24px;margin-bottom:32px}
#server-status + *{margin-top:32px}
.decor-region{position:relative;overflow-x:clip;max-width:100%}
@media(max-width:1380px) and (min-width:769px){
  .head-in{flex-wrap:wrap;gap:12px 24px;padding-top:12px}
  .head-tools{margin-left:auto}
  .main-nav{order:3;flex:1 0 100%;justify-content:flex-start;overflow-x:auto;padding-bottom:10px;scrollbar-width:thin}
}
/* 英文、日文导航标签长,1408 宽的容器一行放不下,桌面端导航一律单独占第二行 */
@media(min-width:769px){
  html:is([lang="en"],[lang="ja"]) .head-in{flex-wrap:wrap;gap:12px 24px;padding-top:12px}
  html:is([lang="en"],[lang="ja"]) .head-tools{margin-left:auto}
  html:is([lang="en"],[lang="ja"]) .main-nav{order:3;flex:1 0 100%;justify-content:flex-start;overflow-x:auto;padding-bottom:10px;scrollbar-width:thin}
}
@media(max-width:1000px){
  .grid-five{grid-template-columns:repeat(3,minmax(0,1fr))}
  .foot-grid{gap:28px}
}
@media(max-width:768px){
  :root{--gutter:20px;--section-space:48px;--size-display:40px;--size-h2:30px;--size-h3:22px}
  .announce{font-size:12.5px}
  .announce-in{flex-wrap:wrap;gap:6px 16px}
  .head-in{flex-wrap:nowrap;min-height:68px;gap:8px}
  .main-nav{display:none}
  .head-tools{margin-left:auto;gap:6px}
  .nav-toggle{display:flex}
  .lang{padding-inline:8px;font-size:12px}
  .login{padding-inline:12px}
  .grid-three,.grid-five,.foot-grid{grid-template-columns:minmax(0,1fr)}
  .panel{padding:24px}
  .foot-grid{gap:32px}
}
@media(max-width:640px){
  .no-break{white-space:normal}
  .tilt,[data-tilt]{transform:none}
  .decor-region,.decor-region > [aria-hidden="true"]{max-width:100%}
}
@media(max-width:380px){
  :root{--gutter:16px}
  .brand{gap:6px}
  .brand-mark{width:28px;height:28px}
  .brand-en{font-size:17px}
  .head-tools{gap:4px}
  .lang{padding-inline:4px}
  .lang svg,.login svg{display:none}
  .login{padding-inline:10px;font-size:13px}
}
@media(prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  *,*::before,*::after{transition-duration:0s!important;animation:none!important}
  .reveal,.reveal.pending{opacity:1;transform:none}
}