Added TOC highlighting

assets/css/custom.css

@@ -17,9 +17,12 @@
 }
 
 .toc:has(#TableOfContents) {
-  background-color: rgba(25, 25, 35, 0.45);
+  background-color: rgba(25, 25, 35, 0.3);
   border-radius: 10px;
   max-height: 70vh;
+  overflow-y: auto;
+  padding: 1rem;
+  scroll-behavior: smooth;
 }
 
 .background-container {
@@ -108,3 +111,44 @@ header button[id^="search-button"]:hover {
     backdrop-filter: blur(8px) hue-rotate(-10deg);
   }
 }
+
+/* TOC link styling */
+#TableOfContents a {
+  color: rgba(255, 255, 255, 0.8);
+  text-decoration: none;
+  transition: all 0.3s ease;
+  display: block;
+  padding: 0.25rem 0;
+}
+
+#TableOfContents a:hover {
+  color: white;
+  transform: translateX(4px);
+}
+
+/* Active TOC item */
+#TableOfContents a.active {
+  color: white;
+  font-weight: 600;
+  transform: translateX(4px);
+  position: relative;
+  transition: all 0.3s ease;
+}
+
+#TableOfContents a.active::before {
+  content: '';
+  position: absolute;
+  left: -1rem;
+  top: 50%;
+  transform: translateY(-50%);
+  width: 4px;
+  height: 1rem;
+  background: linear-gradient(to bottom, #4a9eff, #2d7bda);
+  border-radius: 2px;
+  transition: all 0.3s ease;
+}
+
+/* Remove the default smooth scrolling behavior */
+html {
+  scroll-behavior: smooth;
+}

assets/js/toc-highlight.js

@@ -0,0 +1,151 @@
+document.addEventListener('DOMContentLoaded', function() {
+    const tocLinks = document.querySelectorAll('#TableOfContents a');
+    const tocContainer = document.querySelector('.toc');
+    const sections = new Map(); // Store section elements with their corresponding TOC links
+    let lastActiveSection = null;
+    let scrollTimeout = null;
+    let isScrolling = false;
+    
+    // Build a map of section IDs to their TOC links
+    tocLinks.forEach(link => {
+        const sectionId = decodeURIComponent(link.getAttribute('href').substring(1));
+        const section = document.getElementById(sectionId);
+        if (section) {
+            sections.set(section, link);
+        }
+    });
+
+    // Function to scroll TOC container to keep active item in view
+    const scrollTocToActive = (activeLink) => {
+        if (!tocContainer || !activeLink) return;
+        
+        const containerRect = tocContainer.getBoundingClientRect();
+        const linkRect = activeLink.getBoundingClientRect();
+        
+        // Check if the active link is outside the visible area
+        if (linkRect.top < containerRect.top || linkRect.bottom > containerRect.bottom) {
+            // Calculate the scroll position to center the active link
+            const scrollTop = activeLink.offsetTop - (containerRect.height / 2) + (linkRect.height / 2);
+            
+            // Use CSS smooth scrolling if available, otherwise use JS
+            if ('scrollBehavior' in document.documentElement.style) {
+                tocContainer.scrollTo({
+                    top: scrollTop,
+                    behavior: 'smooth'
+                });
+            } else {
+                // Fallback for browsers that don't support smooth scrolling
+                tocContainer.scrollTop = scrollTop;
+            }
+        }
+    };
+
+    // Function to find the section closest to the center of the viewport
+    const findClosestSectionToCenter = () => {
+        let closestSection = null;
+        let closestDistance = Infinity;
+        const viewportHeight = window.innerHeight;
+        const viewportCenter = viewportHeight / 2;
+        
+        sections.forEach((link, section) => {
+            const rect = section.getBoundingClientRect();
+            // Calculate the center of the section
+            const sectionCenter = rect.top + (rect.height / 2);
+            // Calculate distance from the center of the viewport
+            const distance = Math.abs(sectionCenter - viewportCenter);
+            
+            // If this section is closer to the center than our current closest
+            if (distance < closestDistance) {
+                closestDistance = distance;
+                closestSection = section;
+            }
+        });
+        
+        return closestSection;
+    };
+
+    // Function to update the active section
+    const updateActiveSection = (activeSection) => {
+        if (!activeSection) return;
+        
+        // Update active state
+        tocLinks.forEach(link => link.classList.remove('active'));
+        
+        const activeLink = sections.get(activeSection);
+        if (activeLink) {
+            activeLink.classList.add('active');
+            lastActiveSection = activeSection;
+            
+            // Use a small delay before scrolling to prevent rapid changes
+            if (scrollTimeout) {
+                clearTimeout(scrollTimeout);
+            }
+            
+            scrollTimeout = setTimeout(() => {
+                scrollTocToActive(activeLink);
+            }, 100);
+        }
+    };
+
+    // Function to handle scroll events
+    const handleScroll = () => {
+        // Clear any pending scroll timeout
+        if (scrollTimeout) {
+            clearTimeout(scrollTimeout);
+        }
+        
+        // Find the section closest to the center of the viewport
+        const closestSection = findClosestSectionToCenter();
+        
+        // Update the active section
+        updateActiveSection(closestSection);
+    };
+
+    // Add scroll event listener with debouncing
+    let scrollDebounceTimer = null;
+    window.addEventListener('scroll', () => {
+        isScrolling = true;
+        
+        // Debounce the scroll event
+        if (scrollDebounceTimer) {
+            clearTimeout(scrollDebounceTimer);
+        }
+        
+        scrollDebounceTimer = setTimeout(() => {
+            isScrolling = false;
+            handleScroll();
+        }, 100);
+    });
+
+    // Initial check to ensure a section is highlighted
+    setTimeout(() => {
+        handleScroll();
+    }, 500);
+
+    // Smooth scroll to section when clicking TOC links
+    tocLinks.forEach(link => {
+        link.addEventListener('click', (e) => {
+            e.preventDefault();
+            const targetId = decodeURIComponent(link.getAttribute('href').substring(1));
+            const targetSection = document.getElementById(targetId);
+            if (targetSection) {
+                // Use our custom smooth scrolling function if available
+                if (window.smoothScrollTo) {
+                    window.smoothScrollTo(targetSection);
+                } else {
+                    // Fallback to standard smooth scrolling
+                    targetSection.scrollIntoView({ behavior: 'smooth' });
+                }
+                
+                // Also update the active section immediately
+                const activeLink = sections.get(targetSection);
+                if (activeLink) {
+                    tocLinks.forEach(l => l.classList.remove('active'));
+                    activeLink.classList.add('active');
+                    lastActiveSection = targetSection;
+                    scrollTocToActive(activeLink);
+                }
+            }
+        });
+    });
+}); 

layouts/partials/extend-footer.html

@@ -0,0 +1,4 @@
+{{ if .TableOfContents }}
+  {{ $tocHighlight := resources.Get "js/toc-highlight.js" | js.Build | fingerprint }}
+  <script src="{{ $tocHighlight.RelPermalink }}" integrity="{{ $tocHighlight.Data.Integrity }}" crossorigin="anonymous"></script>
+{{ end }} 

layouts/partials/scripts.html

@@ -1,3 +0,0 @@
-{{ if .Params.showTableOfContents | default (.Site.Params.article.showTableOfContents | default false) }}
-  <script src="/js/scrollspy.js"></script>
-{{ end }}