diff --git a/custom.css b/custom.css
index 54c478d..2b5af42 100644
--- a/custom.css
+++ b/custom.css
@@ -5,93 +5,43 @@
     min-width: 30px !important;
 }
 
-.pagetoc {
-    position: fixed;
-    top: 70px;
-    right: 10px;
-    width: 200px;
-    background: rgba(240, 242, 245, 0.9);
-    border-radius: 5px;
-    border: 1px solid #e1e4e8;
-    font-size: 0.8em;
-    box-shadow: 0 1px 3px rgba(0,0,0,0.1);
-    padding: 10px 10px;
-    max-height: calc(100vh - 120px);
-    overflow-y: auto;
+/* mdBook TOC styling - this targets the actual sidebar TOC */
+.content-wrap {
+    max-width: calc(100% - 220px) !important;
+    margin-right: 220px !important;
 }
 
-.pagetoc h2 {
-    font-size: 1em;
-    margin: 0 0 8px 0;
-    padding-bottom: 5px;
-    border-bottom: 1px solid #e1e4e8;
+.sidebar {
+    background: rgba(245, 245, 247, 0.95) !important;
 }
 
-.pagetoc ul {
-    list-style-type: none;
-    margin: 0;
-    padding: 0 0 0 10px;
-    line-height: 1.3;
+.sidebar-scrollbox {
+    padding: 10px !important;
 }
 
-.pagetoc ul li {
-    margin: 0 0 4px 0;
+.chapter {
+    line-height: 1.3 !important;
+    font-size: 0.9em !important;
 }
 
-.pagetoc a {
-    color: #4183c4;
-    text-decoration: none;
-    display: block;
-    padding: 2px 5px;
-    border-radius: 3px;
-    transition: background-color 0.15s;
-    font-weight: normal;
+.chapter li a {
+    display: block !important;
+    padding: 5px 0 !important;
+    text-overflow: ellipsis !important;
+    overflow: hidden !important;
+    white-space: nowrap !important;
 }
 
-.pagetoc a:hover {
-    background-color: rgba(65, 131, 196, 0.1);
-    text-decoration: none;
+.chapter li a:hover {
+    text-decoration: none !important;
+    background-color: rgba(0, 0, 0, 0.05) !important;
 }
 
-/* Adjust main content to make room for TOC sidebar */
-.content {
-    padding-right: 230px !important;
+.chapter .active {
+    background-color: rgba(0, 0, 0, 0.07) !important;
 }
 
-/* Responsive adjustments */
-@media screen and (max-width: 1250px) {
-    .pagetoc {
-        width: 180px;
-    }
-    
-    .content {
-        padding-right: 200px !important;
-    }
-}
-
-@media screen and (max-width: 1100px) {
-    .pagetoc {
-        width: 150px;
-        font-size: 0.75em;
-        padding: 8px;
-    }
-    
-    .content {
-        padding-right: 170px !important;
-    }
-}
-
-@media screen and (max-width: 800px) {
-    .pagetoc {
-        display: none;
-    }
-    
-    .content {
-        padding-right: 15px !important;
-    }
-}
-
-/* Table of Contents styling for in-page TOC */
+/* Page table of contents styling for in-page TOC */
 .toc {
     background-color: #f8f9fa;
     border: 1px solid #eaecef;
@@ -227,4 +177,41 @@ th {
 .chapter {
     display: block !important;
     visibility: visible !important;
+}
+
+/* mdBook theme-specific adjustments */
+.light .sidebar {
+    background-color: #fafafa !important;
+    border-right: 1px solid #e6e6e6 !important;
+}
+
+.navy .sidebar, .coal .sidebar, .ayu .sidebar {
+    background-color: #292c2f !important;
+    border-right: 1px solid #393f44 !important;
+}
+
+/* Responsive adjustments for the sidebar */
+@media only screen and (max-width: 1300px) {
+    .content-wrap {
+        max-width: calc(100% - 200px) !important;
+        margin-right: 200px !important;
+    }
+}
+
+@media only screen and (max-width: 1080px) {
+    .content-wrap {
+        max-width: calc(100% - 180px) !important;
+        margin-right: 180px !important;
+    }
+    
+    .chapter {
+        font-size: 0.85em !important;
+    }
+}
+
+@media only screen and (max-width: 700px) {
+    .content-wrap {
+        max-width: 100% !important;
+        margin-right: 0 !important;
+    }
 } 
\ No newline at end of file