feat(nav): add anchor TOC in sidebar for toc-enabled pages

- Pass extracted anchors through template context
- Render anchor links under active page when page.toc is true
- Hierarchical indentation by heading level (h2-h6)
- CSS styling: smaller font, muted color, border-left indicator
- Add toc: true to templates.md as example

docs/content/features/templates.md

@@ -2,6 +2,7 @@
 title: Tera Templates
 description: Customizable templates without recompilation
 weight: 1
+toc: true
 ---
 
 sukr uses [Tera](https://tera.netlify.app/), a Jinja2-like templating engine. Templates are loaded at runtime, so you can modify them without recompiling sukr.

docs/static/style.css

@@ -111,6 +111,45 @@ body {
   font-size: 0.9rem;
 }
 
+/* Anchor navigation (TOC in sidebar) */
+.sidebar .nav-anchors {
+  margin-left: 1rem;
+  padding-left: 0.5rem;
+  border-left: 1px solid var(--border);
+  display: flex;
+  flex-direction: column;
+  gap: 0.125rem;
+  margin-top: 0.25rem;
+  margin-bottom: 0.25rem;
+}
+
+.sidebar .nav-anchors .anchor-link {
+  font-size: 0.8rem;
+  color: var(--fg-muted);
+  padding: 0.125rem 0;
+}
+
+.sidebar .nav-anchors .anchor-link:hover {
+  color: var(--accent);
+}
+
+/* Indent anchors by heading level */
+.sidebar .nav-anchors .level-3 {
+  margin-left: 0.5rem;
+}
+
+.sidebar .nav-anchors .level-4 {
+  margin-left: 1rem;
+}
+
+.sidebar .nav-anchors .level-5 {
+  margin-left: 1.5rem;
+}
+
+.sidebar .nav-anchors .level-6 {
+  margin-left: 2rem;
+}
+
 .sidebar-footer {
   margin-top: auto;
   padding-top: 1rem;

docs/templates/base.html

@@ -38,11 +38,25 @@
       {% set section_prefix = item.path | replace(from="index.html", to="") %}
       {% set is_current_section = page_path is starting_with(section_prefix) %}
       <a href="{{ prefix }}{{ item.path }}" {% if page_path==item.path %}class="active" {% endif %}>{{ item.label }}</a>
+      {% if page_path == item.path and page.toc and anchors %}
+      <div class="nav-anchors">
+        {% for anchor in anchors %}
+        <a href="#{{ anchor.id }}" class="anchor-link level-{{ anchor.level }}">{{ anchor.label }}</a>
+        {% endfor %}
+      </div>
+      {% endif %}
       {% if config.nested_nav and item.children %}
       <div class="nav-children{% if is_current_section %} expanded{% endif %}">
         {% for child in item.children %}
         <a href="{{ prefix }}{{ child.path }}" {% if page_path==child.path %}class="active" {% endif %}>{{ child.label
           }}</a>
+        {% if page_path == child.path and page.toc and anchors %}
+        <div class="nav-anchors">
+          {% for anchor in anchors %}
+          <a href="#{{ anchor.id }}" class="anchor-link level-{{ anchor.level }}">{{ anchor.label }}</a>
+          {% endfor %}
+        </div>
+        {% endif %}
         {% endfor %}
       </div>
       {% endif %}

src/main.rs

@@ -142,10 +142,16 @@ fn run(config_path: &Path) -> Result<()> {
         // Render individual content pages for all sections
         for item in &items {
             eprintln!("  processing: {}", item.slug);
-            let (html_body, _anchors) = render::markdown_to_html(&item.body);
+            let (html_body, anchors) = render::markdown_to_html(&item.body);
             let page_path = format!("/{}", item.output_path(&content_dir).display());
-            let html =
-                engine.render_content(item, &html_body, &page_path, &config, &manifest.nav)?;
+            let html = engine.render_content(
+                item,
+                &html_body,
+                &page_path,
+                &config,
+                &manifest.nav,
+                &anchors,
+            )?;
             write_output(&output_dir, &content_dir, item, html)?;
         }
 
@@ -259,9 +265,10 @@ fn process_pages(
             eprintln!("processing: {}", path.display());
 
             let content = Content::from_path(&path, ContentKind::Page)?;
-            let (html_body, _anchors) = render::markdown_to_html(&content.body);
+            let (html_body, anchors) = render::markdown_to_html(&content.body);
             let page_path = format!("/{}", content.output_path(content_dir).display());
-            let html = engine.render_page(&content, &html_body, &page_path, config, nav)?;
+            let html =
+                engine.render_page(&content, &html_body, &page_path, config, nav, &anchors)?;
 
             write_output(output_dir, content_dir, &content, html)?;
         }
@@ -278,13 +285,14 @@ fn generate_homepage(
 ) -> Result<()> {
     eprintln!("generating: homepage");
 
-    let (html_body, _anchors) = render::markdown_to_html(&manifest.homepage.body);
+    let (html_body, anchors) = render::markdown_to_html(&manifest.homepage.body);
     let html = engine.render_page(
         &manifest.homepage,
         &html_body,
         "/index.html",
         config,
         &manifest.nav,
+        &anchors,
     )?;
 
     let out_path = output_dir.join("index.html");

src/template_engine.rs

@@ -8,6 +8,7 @@ use tera::{Context, Tera};
 use crate::config::SiteConfig;
 use crate::content::{Content, NavItem};
 use crate::error::{Error, Result};
+use crate::render::Anchor;
 
 /// Runtime template engine wrapping Tera.
 pub struct TemplateEngine {
@@ -40,11 +41,13 @@ impl TemplateEngine {
         page_path: &str,
         config: &SiteConfig,
         nav: &[NavItem],
+        anchors: &[Anchor],
     ) -> Result<String> {
         let mut ctx = self.base_context(page_path, config, nav);
         ctx.insert("title", &content.frontmatter.title);
         ctx.insert("page", &FrontmatterContext::from(&content.frontmatter));
         ctx.insert("content", html_body);
+        ctx.insert("anchors", anchors);
         self.render("page.html", &ctx)
     }
 
@@ -56,6 +59,7 @@ impl TemplateEngine {
         page_path: &str,
         config: &SiteConfig,
         nav: &[NavItem],
+        anchors: &[Anchor],
     ) -> Result<String> {
         let template = content
             .frontmatter
@@ -66,6 +70,7 @@ impl TemplateEngine {
         ctx.insert("title", &content.frontmatter.title);
         ctx.insert("page", &FrontmatterContext::from(&content.frontmatter));
         ctx.insert("content", html_body);
+        ctx.insert("anchors", anchors);
         self.render(template, &ctx)
     }
 
@@ -145,6 +150,8 @@ pub struct FrontmatterContext {
     pub tags: Vec<String>,
     pub weight: Option<i64>,
     pub link_to: Option<String>,
+    /// Enable table of contents (anchor nav in sidebar)
+    pub toc: bool,
 }
 
 impl From<&crate::content::Frontmatter> for FrontmatterContext {
@@ -156,6 +163,7 @@ impl From<&crate::content::Frontmatter> for FrontmatterContext {
             tags: fm.tags.clone(),
             weight: fm.weight,
             link_to: fm.link_to.clone(),
+            toc: fm.toc.unwrap_or(false),
         }
     }
 }