.topbar{position:-webkit-sticky;position:sticky;top:0;z-index:60;background:var(--glass);backdrop-filter:saturate(160%) blur(14px);-webkit-backdrop-filter:saturate(160%) blur(14px);border-bottom:1px solid var(--line);transition:background .3s ease,box-shadow .3s ease,border-color .3s ease}.topbar.is-scrolled{background:var(--glass-strong);border-bottom-color:var(--line-2);box-shadow:0 6px 22px rgba(31,40,24,.08)}.topbar-inner{justify-content:space-between;max-width:var(--maxw);margin:0 auto;padding:14px 32px;gap:24px}.topbar-inner,.topbar-start{display:flex;align-items:center}.topbar-start{gap:20px;flex:0 0 auto}.topbar-center{display:flex;align-items:center;justify-content:center;flex:1 1 auto;min-width:0;padding:0 16px}.brand{display:inline-flex;align-items:center;gap:12px;min-height:var(--tap-min);font-family:var(--font-serif);font-weight:600;font-size:20px;color:var(--ink);letter-spacing:.1em;position:relative}.brand:focus-visible:after{transform:scaleX(1)}.brand:after{content:"";position:absolute;left:0;right:0;bottom:-4px;height:1px;background:var(--green);transform:scaleX(0);transform-origin:left;transition:transform .35s ease}.brand:hover:after{transform:scaleX(1)}.brand-mark{width:40px;height:40px;object-fit:contain;display:block;filter:drop-shadow(0 2px 6px rgba(63,122,50,.18));transition:transform .35s cubic-bezier(.2,.7,.2,1);flex-shrink:0}.brand:hover .brand-mark{transform:rotate(-6deg) scale(1.06)}.nav{display:flex;gap:12px}.nav,.nav-link{align-items:center}.nav-link{position:relative;display:inline-flex;gap:9px;min-height:auto;padding:0 14px;border-radius:6px;font-size:14px;color:var(--ink-2);letter-spacing:.04em;cursor:pointer;line-height:1;transition:color .2s,background .2s}.nav-link:after{content:"";position:absolute;left:14px;right:14px;bottom:-4px;height:1px;background:var(--green);transform:scaleX(0);transform-origin:left;transition:transform .3s ease}.nav-link.is-active:after,.nav-link:focus-visible:after,.nav-link:hover:after{transform:scaleX(1)}.nav-link.is-active{color:var(--green-2)}.nav-num{font-family:var(--font-serif);font-size:11px;color:var(--muted);font-feature-settings:"tnum";font-variant-numeric:tabular-nums;line-height:1;transition:color .2s,transform .2s}.nav-zh{font-weight:500;line-height:1}.nav-link:focus-visible,.nav-link:hover{color:var(--green-2)}.nav-link.is-active .nav-num,.nav-link:hover .nav-num{color:var(--green);transform:translateX(-1px)}@media(max-width:1020px){.topbar-inner{padding:14px 32px;gap:24px}.topbar-center{display:none}.nav{gap:10px;flex-wrap:nowrap}.nav-link{padding:0 14px;font-size:14px;gap:9px}.nav-num{display:none}.nav-zh{width:auto;line-height:1;white-space:nowrap}}@media(max-width:780px){.topbar-inner{padding:12px 14px;gap:12px}.brand{font-size:16px;letter-spacing:.08em}.brand-mark{width:32px;height:32px}.nav-link{align-items:center;padding:0 10px;font-size:14px;gap:8px}.nav-link:after{left:10px;right:10px;bottom:-4px}}@media(max-width:520px){.topbar-inner{flex-wrap:wrap;justify-content:flex-start;gap:10px}.topbar-start{flex:1 1 auto;min-width:0;gap:12px}.topbar-center{order:3;flex:1 1 100%;padding:0}.nav{order:2;flex:1 1 100%;width:100%;justify-content:space-between;gap:6px;flex-wrap:nowrap}.nav-link{flex:1 1;min-height:var(--tap-min);min-width:0;justify-content:center;padding:8px 6px;font-size:12px;white-space:nowrap}.nav-link:after{left:8px;right:8px}}