*, *::before, *::after { box-sizing: border-box; }
html, body { margin: 0; padding: 0; height: 100%; }
body {
  background: var(--ink);
  color: var(--paper);
  font-family: var(--font-cn);
  -webkit-font-smoothing: antialiased;
  overflow: hidden;
}
.glviewer { position: fixed; inset: 0; z-index: var(--z-gl); }
#gl { display: block; width: 100%; height: 100%; }

.VisuallyHidden {
  position: absolute; width: 1px; height: 1px; margin: -1px;
  padding: 0; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; border: 0;
}
.SkipLink {
  position: absolute; left: var(--sp-4); top: -3rem; z-index: 999;
  background: var(--paper); color: var(--ink); padding: var(--sp-2) var(--sp-4);
  transition: top .2s var(--ease-out);
}
.SkipLink:focus { top: var(--sp-4); }

/* 焦点环用荧光绿 —— 交互层专属色 */
:where(a, button, [tabindex]):focus-visible {
  outline: 2px solid var(--lime);
  outline-offset: 3px;
}

.i18n-en { display: none; }
.lang-en .i18n-zh { display: none; }
.lang-en .i18n-en { display: inline; }

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: .01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .01ms !important;
    scroll-behavior: auto !important;
  }
}