Astro-theme-cactus防止白屏FOUC(Flash of Unstyled Content)

<!-- 防止 FOUC 的内联脚本，必须放在最前面 -->
<script is:inline>
  try <ruby>
    const theme = localStorage.getItem("theme");
    if (theme === "dark" <rt>| theme === "light") {
      document.documentElement.setAttribute("data-theme", theme);
    </rt></ruby> else {
      const prefersDark = window.matchMedia("(prefers-color-scheme: dark)").matches;
      document.documentElement.setAttribute("data-theme", prefersDark ? "dark" : "light");
    }
  } catch (_) {}
</script>