header.site-header{z-index:30;background:rgba(8,9,11,.94);border-bottom:1px solid var(--line);position:sticky}
.site-header .wrap.bar{max-width:1320px;height:76px;min-height:76px;gap:22px;flex-wrap:nowrap;padding:0 28px;position:relative}
.site-header .logo{white-space:nowrap;flex:0 0 auto;gap:10px;font-size:20px;line-height:1}.brand-symbol{width:30px;height:30px;display:grid;place-items:center;background:#111c2b;border:1px solid #314866;border-radius:9px;color:var(--accent);font:500 23px Georgia,serif}
.site-header .primary-nav{display:flex;gap:5px;align-items:center;flex:1 1 auto;justify-content:center;min-width:0;order:initial;width:auto;padding:0;overflow:visible;white-space:nowrap;font-size:14px}
.primary-nav>a,.primary-nav summary{display:flex;align-items:center;gap:6px;padding:9px 12px;border-radius:999px;line-height:1.3;cursor:pointer;list-style:none;color:var(--muted);font-weight:500}
.primary-nav summary::-webkit-details-marker{display:none}.primary-nav summary::after{content:'⌄';font-size:12px;opacity:.7}.primary-nav>a:hover,.primary-nav summary:hover{background:#14181f;color:var(--text)}
.primary-nav>a.on,.primary-nav .is-active>summary{background:#172334;color:var(--accent)}.primary-nav summary:focus-visible{outline:2px solid var(--accent);outline-offset:3px}
.nav-group{position:relative}.nav-panel{position:absolute;left:0;top:calc(100% + 12px);width:264px;padding:8px;background:#101318;border:1px solid var(--line2);border-radius:14px;box-shadow:0 20px 60px #0008;white-space:normal}
.nav-panel a{display:block;padding:11px 12px;border-radius:8px;color:var(--text);font-size:14px;line-height:1.3}.nav-panel a small{display:block;font-size:12px;color:var(--muted);margin-top:5px}.nav-panel a:hover,.nav-panel a.on{background:#192334;color:var(--accent)}.nav-divider{border-top:1px solid var(--line2);margin:6px 8px}
.site-header .header-tools{display:flex;align-items:center;gap:10px;flex:0 0 auto}.site-header .account-actions{display:flex;align-items:center;gap:8px;flex-wrap:nowrap}.site-header .account-actions .btn{padding:9px 17px;font-size:14px;white-space:nowrap;line-height:1.3}.site-header #authUser{max-width:110px;overflow:hidden;text-overflow:ellipsis;white-space:nowrap;font-size:12px}
.site-header [hidden]{display:none!important}.site-search-trigger{display:flex;align-items:center;gap:10px;width:182px;height:38px;padding:0 12px;border:1px solid var(--line2);border-radius:10px;background:#0e1116;color:var(--muted);font:400 13px var(--body);cursor:pointer}.site-search-trigger:hover{border-color:#46546a;color:var(--text)}.site-search-trigger svg{width:16px;height:16px;flex:none}.site-search-trigger kbd{margin-left:auto;border:1px solid var(--line2);border-radius:4px;padding:0 5px;font:400 11px/20px var(--body)}
.mobile-nav-toggle{display:none;width:36px;height:36px;align-items:center;justify-content:center;background:var(--panel);border:1px solid var(--line2);border-radius:9px;color:var(--text);cursor:pointer}.mobile-nav-toggle svg{width:20px;height:20px}
.site-search-dialog{width:min(640px,calc(100vw - 32px));max-height:min(680px,82dvh);padding:0;background:#0e1116;border:1px solid #34445b;border-radius:18px;color:var(--text);box-shadow:0 30px 100px #0009}.site-search-dialog::backdrop{background:#0009;backdrop-filter:blur(5px)}
.site-search-head{display:flex;align-items:center;gap:14px;padding:20px;border-bottom:1px solid var(--line2)}.site-search-head svg{width:20px;height:20px;flex:none;color:var(--accent)}.site-search-head input{min-width:0;width:100%;background:transparent;color:var(--text);border:0;font:400 18px var(--body);outline:none}.site-search-close{border:1px solid var(--line2);border-radius:7px;background:transparent;color:var(--muted);padding:5px 8px;cursor:pointer;font:400 12px var(--body)}
.site-search-hint{padding:14px 20px;font-size:12px;color:var(--muted)}.site-search-results{padding:0 10px 10px;overflow:auto;max-height:450px}.site-search-results a{display:block;padding:12px;border-radius:9px}.site-search-results a:hover,.site-search-results a:focus-visible{background:#192334}.site-search-results b{display:block;font-size:15px;font-weight:500}.site-search-results span{display:block;font-size:12px;color:var(--muted);margin-top:4px}.site-search-empty{padding:24px 12px;color:var(--muted);font-size:14px}
.qi-equation{max-width:100%;min-width:0;overflow-x:auto;overflow-y:hidden;padding:18px 14px;margin:16px 0;background:#0d1520;border:1px solid #24394e;border-radius:10px;color:var(--text);font-size:1rem;line-height:1.5;overscroll-behavior-x:contain}.qi-equation .katex-display{margin:0}.qi-equation .katex{white-space:nowrap}.qi-math-inline .katex{font-size:1.08em}.math-equation:has(>.qi-equation){padding:0;background:transparent}.qi-equation .katex-display>.katex{white-space:nowrap}
.qi-math-inline{display:inline-block;max-width:100%;vertical-align:middle;overflow-x:auto;overflow-y:hidden}
@media(max-width:1100px){.site-header .wrap.bar{gap:12px;padding:0 20px}.primary-nav>a,.primary-nav summary{padding:9px 9px}.site-search-trigger{width:38px;justify-content:center;padding:0}.site-search-trigger span,.site-search-trigger kbd{display:none}}
@media(max-width:960px){.site-header .wrap.bar{height:64px;min-height:64px;justify-content:space-between}.site-header .header-tools{margin-left:auto;gap:8px}.site-header .mobile-nav-toggle{display:flex}.site-header .primary-nav{display:none;position:absolute;left:16px;right:16px;top:calc(100% + 8px);width:auto;max-height:calc(100dvh - 100px);overflow:auto;padding:10px;background:#101318;border:1px solid var(--line2);border-radius:14px;box-shadow:0 20px 60px #0009;align-items:stretch;justify-content:flex-start;gap:4px;z-index:2}.site-header.is-menu-open .primary-nav{display:flex;flex-direction:column}.primary-nav>a,.primary-nav summary{padding:12px;border-radius:8px;justify-content:space-between}.nav-panel{position:static;width:auto;margin:0 5px 6px;padding:3px;border:0;background:#0b1018;box-shadow:none}.site-header #authUser{display:none}.site-header .logo{font-size:18px}}
@media(max-width:400px){.site-header .wrap.bar{padding:0 14px;gap:8px}.site-header .logo{font-size:16px;gap:7px}.brand-symbol{width:25px;height:25px;font-size:20px}.site-header .account-actions .btn{padding:8px 12px}.site-header .header-tools{gap:6px}.site-search-trigger{width:33px;height:34px}}