/* Shared interaction and bilingual helpers */
.lang-zh { display: none; }
body[data-lang="zh"] .lang-en { display: none; }
body[data-lang="zh"] .lang-zh { display: inline; }
body[data-lang="en"] .lang-en { display: inline; }
body[data-lang="en"] .lang-zh { display: none; }

section[id] { scroll-margin-top: 96px; }

.skip-link {
  position: absolute;
  left: 16px;
  top: 12px;
  z-index: 200;
  padding: 10px 14px;
  border-radius: 12px;
  background: #ffffff;
  border: 1px solid rgba(15, 118, 110, 0.24);
  box-shadow: 0 10px 24px rgba(16, 24, 40, 0.08);
  color: #12211e;
  transform: translateY(-140%);
  transition: transform 160ms ease;
}

.skip-link:focus-visible { transform: translateY(0); }

:where(a, button, summary, input, select, textarea, [tabindex]):focus-visible {
  outline: none;
  box-shadow: 0 0 0 4px rgba(15, 118, 110, 0.14);
  border-color: rgba(15, 118, 110, 0.48);
}

:where(a, button, summary, input, select, textarea, [tabindex]):focus:not(:focus-visible) {
  outline: none;
}