.header-actions { display: flex; align-items: center; gap: 26px; }
.language-toggle { display: inline-flex; align-items: center; justify-content: center; flex-shrink: 0; width: 44px; height: 44px; padding: 7px; color: #111; background: transparent; border: 0; border-radius: 4px; font: inherit; cursor: pointer; }
.language-toggle svg { display: block; width: 30px; height: 30px; fill: none; stroke: currentColor; stroke-width: 1.8; stroke-linecap: round; stroke-linejoin: round; }
.language-toggle:hover { background: rgba(47, 85, 151, .06); }
.language-toggle:focus-visible { outline: 2px solid currentColor; outline-offset: 4px; }
.portal-nav .language-toggle { color: #fff; }
.portal-nav .language-toggle:hover { background: rgba(255, 255, 255, .15); }
html[lang="en"] .topic-cn { display: none; }
@media (max-width: 640px) { .header-actions { gap: 14px; } .portal-nav { gap: 12px; } }
@media (max-width: 440px) {
  .header-inner { gap: 8px; }
  .header-actions { gap: 8px; }
  .header-inner .brand { font-size: 16px; gap: 6px; }
  .header-inner .brand img { width: 24px; height: 24px; }
  .header-inner .brand span { display: none; }
  .header-actions .site-nav { gap: 12px; }
  .portal-nav { gap: 10px; }
}