diff --git a/theme/book.js b/theme/book.js
index ec2f0679a2..a422ca6ba4 100644
--- a/theme/book.js
+++ b/theme/book.js
@@ -17,6 +17,33 @@ function playground_text(playground, hidden = true) {
     }
 }
 
+(function openContentLinksInNewTabs() {
+    var content = document.querySelector("#content main");
+    if (!content) {
+        return;
+    }
+
+    Array.from(content.querySelectorAll("a[href]")).forEach(function (link) {
+        var href = link.getAttribute("href");
+
+        // Heading permalinks are page controls, not links to other content.
+        if (!href || link.classList.contains("header") || /^(?:javascript|data):/i.test(href)) {
+            return;
+        }
+
+        link.setAttribute("target", "_blank");
+
+        var rel = (link.getAttribute("rel") || "").split(/\s+/).filter(Boolean);
+        if (rel.indexOf("noopener") === -1) {
+            rel.push("noopener");
+        }
+        if (rel.indexOf("noreferrer") === -1) {
+            rel.push("noreferrer");
+        }
+        link.setAttribute("rel", rel.join(" "));
+    });
+})();
+
 (function codeSnippets() {
     function fetch_with_timeout(url, options, timeout = 6000) {
         return Promise.race([
diff --git a/theme/css/chrome.css b/theme/css/chrome.css
index 403c6779a3..15c677663c 100644
--- a/theme/css/chrome.css
+++ b/theme/css/chrome.css
@@ -1456,21 +1456,25 @@ details[open] > summary::before {
 }
 
 details {
+    --details-content-padding: clamp(1.5rem, 4vw, 4rem);
     border-radius: 8px;
     background-color: var(--bg);
     border: 1px solid var(--table-border-color);
-    font-size: 18px;
-    font-weight: 100;
 }
 
 details p {
-    padding-right: 4rem;
-    padding-left: 4rem;
+    padding-right: var(--details-content-padding);
+    padding-left: var(--details-content-padding);
+}
+
+details > pre {
+    margin-right: var(--details-content-padding);
+    margin-left: var(--details-content-padding);
 }
 
 details ul, details ol {
-    padding-right: 6rem;
-    padding-left: 6rem;
+    padding-right: calc(var(--details-content-padding) + 2rem);
+    padding-left: calc(var(--details-content-padding) + 2rem);
     padding-bottom: 2rem;
     margin-top: 0;
 }
diff --git a/theme/pagetoc.css b/theme/pagetoc.css
index dc6124023c..c33d8fe372 100644
--- a/theme/pagetoc.css
+++ b/theme/pagetoc.css
@@ -95,17 +95,22 @@
     }
     .sidetoc-wrapper {
         position: fixed;
+        top: calc(var(--menu-bar-height) + 25px);
+        bottom: 25px;
         width: 250px;
-        height: calc(100vh - var(--menu-bar-height)  - 50px * 2);
-        overflow: auto;
+        height: auto;
+        overflow: hidden;
         display: flex;
         flex-direction: column;
         gap:14px;
         background-color: transparent;
     }
     .pagetoc {
-        max-height: 48%;
-        overflow: auto;
+        flex: 1 1 auto;
+        min-height: 0;
+        max-height: none;
+        overflow-x: hidden;
+        overflow-y: auto;
         border-left: 1px solid color-mix(in srgb, var(--table-border-color) 70%, transparent);
         border-radius: 12px;
         background: transparent;
@@ -113,8 +118,10 @@
         padding: 4px 4px;
     }
     .sidesponsor {
-        max-height: 52%;
-        height: 52%;
+        flex: 0 1 auto;
+        max-height: min(420px, 52vh);
+        height: auto;
+        margin-top: auto;
         background-color: transparent;
         border: 1px solid color-mix(in srgb, var(--table-border-color) 70%, transparent);
         border-radius: 8px;
@@ -192,8 +199,10 @@
         font-weight: 800;
     }
     .sidesponsor-bsa {
-        max-height: 52%;
-        height: 52%;
+        flex: 0 1 auto;
+        max-height: min(420px, 52vh);
+        height: auto;
+        margin-top: auto;
         background-color: transparent;
         border: 1px solid color-mix(in srgb, var(--table-border-color) 70%, transparent);
         border-radius: 8px;
@@ -781,8 +790,8 @@
 .sidesponsor {
     width: 100% !important;
     min-height: min(360px, 52vh);
-    max-height: 52% !important;
-    height: 52% !important;
+    max-height: min(420px, 52vh) !important;
+    height: auto !important;
     grid-template-columns: minmax(0, 1fr);
     grid-template-areas:
         "kicker"
@@ -911,8 +920,8 @@
     }
 
     .sidesponsor-bsa {
-        max-height: 52%;
-        height: 52%;
+        max-height: min(420px, 52vh);
+        height: auto;
     }
 }
 
diff --git a/theme/toc.js.hbs b/theme/toc.js.hbs
index b6b5566e52..1e99281481 100644
--- a/theme/toc.js.hbs
+++ b/theme/toc.js.hbs
@@ -11,35 +11,24 @@ class MDBookSidebarScrollbox extends HTMLElement {
         // Modify TOC to support external links
         var toc = '{{#toc}}{{/toc}}';
         // Handle both old mdbook (<div>) and new mdbook 0.5 (<span>) formats
-        // External links open in new tab with external link icon
-        toc = toc.replace(/<(div|span)>([^$<>]*)\$\$external:([^$<>]*)\$\$<\/(div|span)>/g, '<a class="external-link" href="$3" target="_blank" rel="noopener noreferrer">$2 ↗</a>') 
+        // External links open in a new tab. CSS adds the single external-link icon.
+        toc = toc.replace(/<(div|span)>([^$<>]*)\$\$external:([^$<>]*)\$\$<\/(div|span)>/g, '<a class="external-link" href="$3" target="_blank" rel="noopener noreferrer">$2</a>')
         this.innerHTML = toc
         // Set the current, active page, and reveal it if it's hidden
-        let current_page = document.location.href.toString();
-        if (current_page.endsWith("/")) {
-            current_page += "index.html";
-        }
+        var currentPage = normalizeChapterUrl(document.location.href);
         var links = Array.prototype.slice.call(this.querySelectorAll("a"));
         var l = links.length;
         for (var i = 0; i < l; ++i) {
             var link = links[i];
             var href = link.getAttribute("href");
-            if (href && !href.startsWith("#") && !/^(?:[a-z+]+:)?\/\//.test(href)) {
+            var isChapterLink = href && !href.startsWith("#") && !link.classList.contains("chapter-fold-toggle") && !link.classList.contains("external-link");
+            if (isChapterLink && !/^(?:[a-z+]+:)?\/\//.test(href)) {
                 link.href = path_to_root + href;
             }
             // The "index" page is supposed to alias the first chapter in the book.
-            if (link.href === current_page || (i === 0 && path_to_root === "" && current_page.endsWith("/index.html"))) {
+            if (isChapterLink && (normalizeChapterUrl(link.href) === currentPage || (i === 0 && path_to_root === "" && currentPage.endsWith("/index.html")))) {
                 link.classList.add("active");
-                var parent = link.parentElement;
-                if (parent && parent.classList.contains("chapter-item")) {
-                    parent.classList.add("expanded");
-                }
-                while (parent) {
-                    if (parent.tagName === "LI" && parent.classList.contains("chapter-item")) {
-                        parent.classList.add("expanded");
-                    }
-                    parent = parent.parentElement;
-                }
+                expandChapterPath(link);
             }
         }
         updateChapterNavigation(links);
@@ -99,6 +88,14 @@ function normalizeChapterUrl(url) {
     }
 }
 
+function expandChapterPath(link) {
+    var chapter = link.closest("li.chapter-item");
+    while (chapter) {
+        chapter.classList.add("expanded");
+        chapter = chapter.parentElement && chapter.parentElement.closest("li.chapter-item");
+    }
+}
+
 function setChapterNavigationLink(selector, chapter) {
     var link = document.querySelector(selector);
     if (!link) {