<?xml version="1.0" encoding="UTF-8"?>
<!--
  Sitemap index — PrepLearnio multilingual SEO (Phase 1, 2026-06-21)
  Each language gets its own sitemap file; this index points to all of them.
  robots.txt already references this file as the sitemap entry point.

  Phase 1  (done):  sitemap-en.xml  — 78 English pages
  Phase 2  (done):  sitemap-zh.xml  — 12 Chinese core pages (/zh/...)
  Phase 4  (todo):  sitemap-ja.xml  — Japanese  pages (/ja/...)
  Phase 5  (todo):  sitemap-ko.xml  — Korean    pages (/ko/...)
-->
<sitemapindex xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">
  <sitemap>
    <loc>https://preplearnio.com/sitemap-en.xml</loc>
    <lastmod>2026-06-21</lastmod>
  </sitemap>
  <sitemap>
    <loc>https://preplearnio.com/sitemap-zh.xml</loc>
    <lastmod>2026-06-21</lastmod>
  </sitemap>
  <!-- sitemap-ja.xml added in Phase 4 -->
  <!-- sitemap-ko.xml added in Phase 5 -->
</sitemapindex>
