/* Full-width navigation menus, with shared groups on desktop and mobile. */
#header-box{--nav-bg:#fff;--nav-card:#f2f5f7;--nav-line:#e2e7ec;--nav-text:#263541;--nav-muted:#6d7b87;--nav-accent:#2580b8;--mega-top:64px;background:var(--nav-bg)!important;border-bottom:1px solid var(--nav-line)!important}
.dark #header-box{--nav-bg:#111416;--nav-card:#1c2227;--nav-line:#272e34;--nav-text:#e3e7eb;--nav-muted:#97a2ad;--nav-accent:#79bce7}
#header-box .nav-row{gap:20px}#header-box .nav-center{gap:4px}#header-box .nav-link{gap:6px;padding:10px 12px;border-radius:7px;color:var(--nav-muted);font-size:16px;font-weight:400;white-space:nowrap}#header-box .nav-center .nav-link-icon{display:none}#header-box .nav-link:hover,#header-box .nav-link.is-open,#header-box .nav-link-active{background:var(--nav-card)!important;color:var(--nav-text)!important}#header-box .nav-link-caret{width:13px;height:13px;opacity:.55;transition:transform .15s}#header-box .nav-link.is-open .nav-link-caret{transform:rotate(180deg)}.dark .a2-nav-chevron{filter:invert(1)}
#header-box .a2-mega-panel{position:fixed!important;top:var(--mega-top)!important;left:0!important;right:0!important;width:100%!important;min-width:0!important;max-width:none!important;margin:0!important;padding:26px max(32px,calc((100vw - 1184px)/2)) 30px!important;border:0!important;border-bottom:1px solid var(--nav-line)!important;border-radius:0!important;background:var(--nav-bg)!important;box-shadow:0 18px 28px #0003;transform:none!important;max-height:calc(100dvh - var(--mega-top) - 16px);overflow-y:auto;overscroll-behavior:contain}
.a2-mega-grid{display:grid;grid-template-columns:repeat(var(--mega-columns),minmax(0,1fr));gap:24px;text-align:left;font-family:"Encode Sans","Microsoft YaHei",sans-serif}.a2-mega-group{min-width:0}.a2-mega-group h3{margin:0 0 10px;padding:0 0 10px;border-bottom:1px solid var(--nav-line);font-size:14px;font-weight:500;color:var(--nav-muted)}.a2-mega-link{display:flex;align-items:center;gap:10px;min-height:40px;padding:6px;border-radius:6px;color:var(--nav-text)!important;text-decoration:none;cursor:pointer;list-style:none}.a2-mega-link::-webkit-details-marker{display:none}.a2-mega-link:hover,.a2-mega-branch[open]>.a2-mega-link{background:var(--nav-card)}.a2-mega-icon{display:grid;place-items:center;flex:none;width:32px;height:32px;border-radius:6px;background:var(--nav-card)}.a2-mega-icon img{width:18px;height:18px;opacity:.8}.a2-mega-copy{display:block;min-width:0;flex:1}.a2-mega-copy b{display:block;font-size:15px;font-weight:500;line-height:1.5}.a2-mega-copy small{display:block;margin-top:3px;color:var(--nav-muted);font-size:13px;line-height:1.5}.a2-mega-link>img{width:16px;height:16px;flex:none;opacity:.6}.dark .a2-mega-grid img{filter:invert(1)}.a2-mega-branch{position:relative}.a2-mega-children{position:fixed;z-index:3;width:215px;max-height:min(440px,calc(100dvh - var(--mega-top) - 24px));overflow:auto;padding:7px;border:1px solid var(--nav-line);border-radius:8px;background:var(--nav-bg);box-shadow:0 12px 28px #0005;overscroll-behavior:contain}.a2-mega-children>a{display:block;padding:8px 11px;border-radius:4px;color:var(--nav-text);text-decoration:none;font-size:14px;line-height:1.5}.a2-mega-children>a:hover{background:var(--nav-card);color:var(--nav-accent)}.a2-mega-children>.a2-mega-all{border-bottom:1px solid var(--nav-line);border-radius:0;color:var(--nav-accent);margin-bottom:5px}.a2-mega-grid a:focus-visible,.a2-mega-grid summary:focus-visible{outline:2px solid var(--nav-accent);outline-offset:1px}
#header-box .nav-actions .search-box{height:34px;width:190px;padding:0 10px;border-color:var(--nav-line);background:var(--nav-card);border-radius:5px;gap:8px}#header-box .search-box>span:nth-child(2){font-size:14px;overflow:hidden;text-overflow:ellipsis}#header-box .search-box kbd{white-space:nowrap;font:10px/1.5 system-ui;color:var(--nav-muted)}
@media(min-width:1200px){#header-box .nav-search-full{display:inline-flex!important}#header-box .nav-search-compact{display:none!important}}
@media(min-width:1024px) and (max-width:1450px){#header-box .nav-row{gap:8px}#header-box .nav-link{padding:9px 9px;font-size:16px}#header-box .nav-actions{gap:2px}#header-box .nav-actions .search-box{width:160px}}
@media(max-width:1023px){#header-box .nav-center{display:none!important}}
/* Sidebar reuses the same groups with inline disclosure panels. */
.a2-mega-side{--nav-bg:#fff;--nav-card:#f2f5f7;--nav-line:#e2e7ec;--nav-text:#263541;--nav-muted:#6d7b87;--nav-accent:#2580b8;display:block;padding:6px 0}.dark .a2-mega-side{--nav-bg:#14191e;--nav-card:#222a32;--nav-line:#2c363f;--nav-text:#e3e7eb;--nav-muted:#97a2ad;--nav-accent:#79bce7}.a2-mega-side .a2-mega-group{margin-bottom:18px}.a2-mega-side .a2-mega-group h3{margin-left:6px}.a2-mega-side .a2-mega-children{position:static;width:auto;max-height:300px;margin:4px 0 8px 18px;box-shadow:none}.a2-mega-side .a2-mega-branch[open]>summary>img{transform:rotate(90deg)}
@media(prefers-reduced-motion:reduce){#header-box .nav-link-caret{transition:none}}
/* Avoid transformed ancestors capturing the viewport-wide dropdown. */
#header-box{backdrop-filter:none!important;-webkit-backdrop-filter:none!important}
#header-box .nav-center{position:static!important;transform:none!important;flex:0 0 auto;margin-inline:auto}
#header-box .nav-brand{flex:1;min-width:0}#header-box .nav-actions{flex:1;justify-content:flex-end}
@media(min-width:1200px){#header-box .nav-brand-name-short{display:inline!important;color:var(--nav-text);font-size:14px;font-weight:650;white-space:nowrap}#header-box .nav-brand-name-full{display:none!important}}
.a2-mega-side .a2-mega-children{max-height:none;overflow:visible}

/* Stronger contrast for the main navigation in dark mode. */
.dark #header-box .nav-center .nav-link,.dark #header-box .nav-center .nav-link:hover,.dark #header-box .nav-center .nav-link.is-open,.dark #header-box .nav-center .nav-link-active{color:#fff!important}