diff --git a/index.js b/index.js
index e6dc0fd..e3a095d 100644
--- a/index.js
+++ b/index.js
@@ -20,6 +20,9 @@ async function initializeMarked() {
         const isExternal = href.startsWith('http') || href.startsWith('https');
         const attrs = isExternal ? ' target="_blank" rel="noopener noreferrer"' : '';
         const link = originalLink(href, title, text);
+        if (!isExternal && href.startsWith('?')) {
+            return link.replace(/^<a /, '<a data-internal="true" ');
+        }
         return link.replace(/^<a /, `<a${attrs} `);
     };
 
@@ -327,6 +330,7 @@ async function loadDocument(path) {
 
         documentOutline.innerHTML = '';
         const headings = documentContent.querySelectorAll('h1, h2, h3, h4, h5, h6');
+        const headingLinks = new Map();
         
         headings.forEach(heading => {
             if (!heading.id) {
@@ -338,34 +342,50 @@ async function loadDocument(path) {
             const link = document.createElement('a');
             link.href = `${window.location.pathname}${window.location.search}#${heading.id}`;
             link.textContent = heading.textContent;
-            link.style.paddingLeft = (heading.tagName[1] - 1) * 15 + 'px';
+            // Add non-zero indentation
+            link.style.paddingLeft = (heading.tagName[1] * 15) + 'px';
+            headingLinks.set(heading, link);
             
+            // Add extra space to avoid scrolling beneath the header
+            heading.style.scrollMarginTop = 'var(--title-bar-height)';
+
             link.onclick = (e) => {
                 e.preventDefault();
                 history.pushState(null, '', link.href);
-                
-                document.querySelectorAll('.highlight').forEach(el => {
-                    el.classList.remove('highlight');
-                });
-                
-                heading.classList.add('highlight');
-                
-                heading.scrollIntoView({ behavior: 'smooth' });
+                if (heading) {
+                    heading.scrollIntoView({ behavior: 'smooth', block: 'start' });
+                    heading.classList.remove('highlight');
+                    void heading.offsetWidth;
+                    heading.classList.add('highlight');
+                } else {
+                    window.scrollTo({ top: 0, behavior: 'smooth' });
+                }
             };
             
             documentOutline.appendChild(link);
         });
 
-        if (window.location.hash) {
-            const id = window.location.hash.substring(1);
-            const heading = document.getElementById(id);
-            if (heading) {
-                heading.classList.add('highlight');
-                heading.scrollIntoView({ behavior: 'smooth' });
+        // Replace the existing observer with this refined version
+        const observer = new IntersectionObserver((entries) => {
+            const visibleHeadings = entries
+                .filter(entry => entry.isIntersecting)
+                .sort((a, b) => a.target.offsetTop - b.target.offsetTop);
+            if (visibleHeadings.length) {
+                documentOutline.querySelectorAll('a').forEach(a => a.classList.remove('active'));
+                const topHeading = visibleHeadings[0].target;
+                const link = headingLinks.get(topHeading);
+                if (link) link.classList.add('active');
             }
-        }
+        }, {
+            rootMargin: '-48px 0px -60% 0px',
+            threshold: [0, 0.25, 0.5, 0.75, 1]
+        });
+
+        headings.forEach(heading => observer.observe(heading));
+
+        // Clean up observer when loading new document
+        return () => observer.disconnect();
 
-        Prism.highlightAll();
     } catch (error) {
         console.error('Error loading document:', error);
         document.getElementById('document-content').innerHTML = 
@@ -417,3 +437,20 @@ window.addEventListener('load', () => {
             '<div class="error">Failed to load documentation. Please try refreshing the page.</div>';
     });
 });
+
+// Globally intercept clicks on internal links
+document.addEventListener('click', async (e) => {
+    const target = e.target.closest('a[data-internal="true"]');
+    if (target) {
+        e.preventDefault();
+        const slug = target.href.split('?').pop();
+        const indexData = await fetch('index.json').then(res => res.json());
+        const matchingDoc = findDocumentBySlug(indexData.documents, slug);
+        if (matchingDoc) {
+            await loadDocument(matchingDoc.path);
+            // Scroll to the top after loading
+            window.scrollTo({ top: 0, behavior: 'smooth' });
+            history.pushState(null, '', target.href);
+        }
+    }
+});
diff --git a/styles.css b/styles.css
index c020644..7246690 100644
--- a/styles.css
+++ b/styles.css
@@ -67,8 +67,9 @@ body {
     right: 0;
     bottom: 0;
     width: var(--doc-outline-width);
-    background: var(--ifm-background-color);
+    background: var(--ifm-background-color);  /* Change to match main content */
     overflow-y: auto;
+    border-left: none;  /* Explicitly remove border */
 }
 
 .content {
@@ -81,15 +82,17 @@ body {
 #file-index {
     flex: 1;
     overflow-y: auto;
+    padding-top: 20px;
 }
 
 @media (max-width: 1000px) {
     .menu-button {
-        display: flex;
+        display: flex !important;  /* Force display on mobile */
     }
 
     .left-sidebar {
         left: -100%;
+        width: min(var(--doc-sidebar-width), 80vw);  /* Limit width on mobile */
         transition: left 0.3s ease; /* Change to left transition */
         box-shadow: none;
     }
@@ -108,19 +111,35 @@ body {
         margin-right: 0;
         padding: 1rem;
     }
+
+    .markdown-content {
+        padding: 0 0.5rem;
+    }
+
+    #file-index {
+        padding-top: 0.75rem;  /* Add top padding to menu */
+    }
+}
+
+@media (max-width: 480px) {
+    .content {
+        padding: 0.75rem 0.5rem;
+    }
+
+    .markdown-content {
+        padding: 0 0.25rem;
+    }
 }
 
 .menu-button {
-    display: none;
+    display: none;  /* Initially hidden */
     background: none;
     border: none;
     color: var(--ifm-color-content);
     padding: 8px;
     cursor: pointer;
-    font-size: 1.2rem;
     width: 40px;
     height: 40px;
-    display: flex;
     align-items: center;
     justify-content: center;
 }
@@ -134,7 +153,6 @@ body {
 }
 
 .sidebar {
-    background-color: var(--ifm-background-surface-color);
     color: var(--ifm-color-content);
     overflow-y: auto;
     border-color: var(--ifm-border-color);
@@ -145,7 +163,7 @@ body {
     color: var(--ifm-color-content);
     text-decoration: none;
     display: block;
-    padding: 0.4rem 1.2rem;
+    padding: 0.6rem 1.2rem;  /* Increased vertical padding */
     font-size: 0.875rem;
     border-left: 2px solid transparent;
 }
@@ -198,7 +216,7 @@ body {
 }
 
 .social-links {
-    padding: 1rem 1rem 0.5rem;
+    padding: 0.5rem 1rem;
     display: flex;
     justify-content: center;
     gap: 1rem;
@@ -219,7 +237,7 @@ social-links a:hover {
 .subtitle {
     margin-top: auto;  /* Push to bottom of flex container */
     text-align: center;
-    padding: 0 1rem 1rem;
+    padding: 0.5rem 1rem;
     font-size: 0.8rem;
     color: var(--ifm-color-content-secondary);
     border-top: 1px solid var(--ifm-border-color);
@@ -240,7 +258,6 @@ social-links a:hover {
 .content {
     flex: 1;
     background-color: var(--ifm-background-color);
-    padding: 2rem 3rem;
     overflow-y: scroll;
     min-width: 0;  /* Fix flexbox content overflow */
     color: var(--ifm-color-content);
@@ -262,17 +279,23 @@ social-links a:hover {
 }
 
 #document-outline {
-    padding: 0 1rem;  /* Add horizontal padding */
+    padding: 1rem;
 }
 
 #document-outline a {
     color: var(--ifm-color-content-secondary);
     border-left: 2px solid transparent;
     margin: 2px 0;
-    padding: 0.4rem 1rem;  /* Adjust padding to match */
+    padding: 0.25em 1rem;  /* Adjust padding to match */
+    transition: all 0.2s ease;
+}
+
+#document-outline a.active {
+    color: var(--ifm-color-primary);
+    border-left-color: var(--ifm-color-primary);
+    background: rgba(33, 150, 243, 0.1);
 }
 
-/* Markdown content styling */
 .markdown-content {
     line-height: 1.7;
     font-size: 1rem;
@@ -477,3 +500,10 @@ social-links a:hover {
 .title-text .page-title {
     font-size: 0.9rem;
 }
+
+#document-outline a.active {
+    /* Remove any forced padding-left: 0; here */
+    color: var(--ifm-color-primary);
+    border-left-color: var(--ifm-color-primary);
+    background: rgba(33, 150, 243, 0.1);
+}