/* Nút chuyển ngôn ngữ, để riêng khỏi style.css cho dễ theo dõi phần song ngữ. */

.lang-switch {
  display: inline-flex;
  margin-left: auto;
  border: 1px solid var(--border);
  border-radius: 999px;
  overflow: hidden;
  font-family: "JetBrains Mono", ui-monospace, monospace;
  font-size: 0.75rem;
  line-height: 1;
  flex: none;
}
.lang-switch a {
  padding: 0.42rem 0.75rem;
  color: var(--muted);
  background: var(--surface);
  text-decoration: none;
  transition: background 150ms, color 150ms;
}
.lang-switch a:hover { color: var(--ink); }
.lang-switch a[aria-current="true"] {
  background: var(--accent);
  color: #1a0403;
  font-weight: 600;
}

@media (max-width: 40rem) {
  .site-header .wrap { height: auto; padding-top: 0.6rem; padding-bottom: 0.6rem; flex-wrap: wrap; }
  .lang-switch { margin-left: auto; }
}