main.feat/issue-212-heading-breadcrumbs.reviews/camera/leica/m11-p/index.html.<div class="hotspot-popup"> blocks inside the <section id="explorer-section">.<h4> tags with <h3> tags to restore heading order hierarchy (h2 -> h3)..breadcrumbs styling to assets/css/style.css (using .breadcrumbs ol, .breadcrumbs li, and separator content //).reviews/index.html, inject <nav aria-label="Breadcrumb" class="breadcrumbs">... immediately after the <main> tag and before <h1 class="page-title">.reviews/camera/leica/m11-p/index.html, inject the breadcrumb <nav> inside <main> right before or inside <article class="container">.reviews/camera/fujifilm/x100vi/index.html, inject the breadcrumb <nav> inside <main> right before or inside <article class="container">.bundle exec jekyll build..github/workflows/validate_html.yml checks (if executable locally) or ensure no raw Markdown in HTML.h1 matches in modified files.h4 tags exist in reviews/camera/leica/m11-p/index.html.feat: add semantic breadcrumbs and fix heading order in reviews (#212)).main.