diff --git a/assets/css/critical.css b/assets/css/critical.css
new file mode 100644
index 0000000..4a771dd
--- /dev/null
+++ b/assets/css/critical.css
@@ -0,0 +1,29 @@
+/*
+ * Critical CSS — inlined into via partials/head/critical-css.html.
+ * Keep this file small: it is rendered on every page before main.css loads.
+ *
+ * Currently scoped to text-selection highlighting so the chosen color shows
+ * even before the main bundle is parsed.
+ */
+
+*::selection {
+ background-color: var(--color-primary, #4a90e2) !important;
+ color: var(--color-white, #ffffff) !important;
+ text-shadow: none !important;
+}
+
+*::-moz-selection {
+ background-color: var(--color-primary, #4a90e2) !important;
+ color: var(--color-white, #ffffff) !important;
+ text-shadow: none !important;
+}
+
+html[data-theme="dark"] *::selection {
+ background-color: #e9996b !important;
+ color: #1a2633 !important;
+}
+
+html[data-theme="dark"] *::-moz-selection {
+ background-color: #e9996b !important;
+ color: #1a2633 !important;
+}
diff --git a/layouts/partials/head.html b/layouts/partials/head.html
index a2d894a..8c331d6 100644
--- a/layouts/partials/head.html
+++ b/layouts/partials/head.html
@@ -1,89 +1,44 @@
-
- {{/* SEO Critical Resources - Must come first */}}
- {{ partial "seo/preload-resources.html" . }}
-
- {{/* Consolidated Meta Tags with SEO */}}
- {{ partial "head/meta.html" . }}
-
- {{/* Structured Data */}}
- {{ partial "seo/schema-org.html" . }}
-
-
- {{ partial "head/favicons.html" . }}
-
-
- {{ partial "head/critical-css.html" . }}
-
-
- {{ partial "head/styles.html" . }}
-
- {{/* Math Support - Load early for better rendering */}}
- {{- if .Params.math -}}
-
-
-
-
-
-
-
-
- {{- end -}}
+{{/*
+ head.html — emits CHILDREN ONLY.
-
- {{ with site.Params.seo.google_site_verification }}
-
- {{ end }}
- {{ with site.Params.seo.bing_verification }}
-
- {{ end }}
- {{ with site.Params.seo.yandex_verification }}
-
- {{ end }}
+ Ownership: layouts/_default/baseof.html opens and closes .
+ Do NOT add a literal / here, otherwise the document would
+ contain nested heads.
+*/}}
-
- {{ partial "analytics.html" . }}
+{{/* SEO Critical Resources - Must come first */}}
+{{ partial "seo/preload-resources.html" . }}
-
- {{ with resources.Get "js/main.js" }}
- {{ $mainJS := . | js.Build | minify | fingerprint }}
-
- {{ end }}
-
-
- {{ $pdfJS := resources.Get "js/pdf-generator.js" | minify | fingerprint }}
-
-
-
- {{ $scrollbarFadeJS := resources.Get "js/scrollbar-fade.js" | minify }}
-
+{{/* Consolidated Meta Tags with SEO (cached per URL — meta varies per page) */}}
+{{ partialCached "head/meta.html" . .RelPermalink }}
- {{/* Math rendering scripts - Load after DOM is ready */}}
- {{- if .Params.math -}}
-
-
+{{/* Structured Data */}}
+{{ partial "seo/schema-org.html" . }}
-
-
+
+{{ partial "head/favicons.html" . }}
-
-
+
+{{ partial "head/critical-css.html" . }}
-
-
- {{- end -}}
-
\ No newline at end of file
+
+{{ partial "head/styles.html" . }}
+
+{{/* TODO: replaced by Unit 11 katex partial — assets/js/katex-init.js + head/katex.html */}}
+
+
+{{ with site.Params.seo.google_site_verification }}
+
+{{ end }}
+{{ with site.Params.seo.bing_verification }}
+
+{{ end }}
+{{ with site.Params.seo.yandex_verification }}
+
+{{ end }}
+
+
+{{ partial "analytics.html" . }}
+
+
+{{ partial "head/js.html" . }}
diff --git a/layouts/partials/head/critical-css.html b/layouts/partials/head/critical-css.html
index 5f9a844..b753cda 100644
--- a/layouts/partials/head/critical-css.html
+++ b/layouts/partials/head/critical-css.html
@@ -1,40 +1,15 @@
-
+{{/*
+ critical-css.html — inlines the canonical theme-init JS (assets/js/critical.js)
+ and the small critical CSS bundle (assets/css/critical.css) into .
+
+ This is the SINGLE place that emits the theme-init script. Other partials
+ must not duplicate the localStorage/data-theme bootstrap.
+*/}}
{{ $criticalJS := resources.Get "js/critical.js" | js.Build | minify }}
-
+{{ with resources.Get "css/critical.css" }}
+ {{ $criticalCSS := . | minify }}
+
+{{ end }}
diff --git a/layouts/partials/head/js.html b/layouts/partials/head/js.html
index 88f92fd..23f982f 100644
--- a/layouts/partials/head/js.html
+++ b/layouts/partials/head/js.html
@@ -1,26 +1,24 @@
-
-
+{{/*
+ js.html — application JS bundles. Theme-init is handled in critical-css.html
+ via assets/js/critical.js, do not duplicate it here.
-{{- with resources.Get "js/main.js" }}
- {{- if eq hugo.Environment "development" }}
- {{- with . | js.Build }}
-
- {{- end }}
- {{- else }}
- {{- $opts := dict "minify" true }}
- {{- with . | js.Build $opts | fingerprint }}
-
- {{- end }}
+ Production: minify, drop console/debugger, fingerprint with SRI.
+ Development: external sourceMap, no minify, no SRI (faster rebuilds).
+*/}}
+
+{{- $jsOpts := dict "sourceMap" "external" -}}
+{{- if hugo.IsProduction -}}
+ {{- $jsOpts = dict "minify" true "drop" (slice "console" "debugger") -}}
+{{- end -}}
+
+{{- range (slice "js/main.js" "js/pdf-generator.js" "js/scrollbar-fade.js") }}
+ {{- with resources.Get . }}
+ {{- $built := . | js.Build $jsOpts -}}
+ {{- if hugo.IsProduction -}}
+ {{- $built = $built | fingerprint -}}
+
+ {{- else -}}
+
+ {{- end -}}
{{- end }}
{{- end }}
diff --git a/layouts/partials/head/meta.html b/layouts/partials/head/meta.html
index c210914..caf4435 100644
--- a/layouts/partials/head/meta.html
+++ b/layouts/partials/head/meta.html
@@ -3,8 +3,20 @@
-
-
+{{/*
+ Content Security Policy.
+ - Configurable via site.Params.security.csp (whole policy string).
+ - Default keeps 'unsafe-inline' on script-src because critical-css.html
+ inlines theme-init JS via safeJS, and on style-src for the inlined
+ critical CSS