diff --git a/whitepaper/inject-whitepaper-css.py b/whitepaper/inject-whitepaper-css.py
index 8ff3b5b..ea488a9 100644
--- a/whitepaper/inject-whitepaper-css.py
+++ b/whitepaper/inject-whitepaper-css.py
@@ -76,6 +76,122 @@ main img, section img {{
   object-fit: contain;
   box-shadow: 0 12px 48px rgba(0, 0, 0, 0.6);
 }}
+/* Left-rail table of contents. Cancels the same docutils responsive.css
+   `body > *` blanket rule that broke the uncloseai button (padding /
+   margin / max-width / background / line-height) and then lays the
+   sidebar out as a fixed left rail on wide viewports. Below 1100px the
+   sidebar collapses behind a toggle button so it cannot crowd the
+   single-column reading flow on phones and narrow laptops. */
+body > .wp-toc {{
+  all: revert;
+  position: fixed;
+  top: 0;
+  left: 0;
+  bottom: 0;
+  width: 280px;
+  padding: 1.25rem 1rem 1.25rem 1.5rem;
+  margin: 0;
+  background: #fafafa;
+  border-right: 1px solid #e5e5e5;
+  overflow-y: auto;
+  overflow-x: hidden;
+  z-index: 50;
+  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica,
+               Arial, sans-serif;
+  font-size: 0.82rem;
+  line-height: 1.4;
+  box-sizing: border-box;
+}}
+.wp-toc-title {{
+  font-family: 'chunkfive', Georgia, serif;
+  font-size: 1.15rem;
+  margin: 0 0 0.6rem 0;
+  color: #227842;
+  letter-spacing: 0.02em;
+}}
+.wp-toc-title .period {{ color: #227842; }}
+.wp-toc ol {{
+  list-style: none;
+  padding: 0;
+  margin: 0;
+}}
+.wp-toc li {{
+  margin: 0;
+}}
+.wp-toc a {{
+  display: block;
+  padding: 0.22rem 0.4rem;
+  color: #333;
+  text-decoration: none;
+  border-left: 2px solid transparent;
+  border-radius: 0 3px 3px 0;
+  word-wrap: break-word;
+}}
+.wp-toc a:hover {{
+  background: #efefef;
+  color: #000;
+}}
+.wp-toc a.active {{
+  background: #e8f1ec;
+  color: #155c30;
+  border-left-color: #227842;
+  font-weight: 600;
+}}
+.wp-toc li.lvl-3 a {{
+  padding-left: 1.2rem;
+  font-size: 0.78rem;
+  color: #555;
+}}
+.wp-toc li.lvl-3 a.active {{
+  color: #155c30;
+}}
+/* Toggle button — hidden on wide viewports, shown when the sidebar
+   collapses. Same `all: revert` trick so docutils does not stretch it. */
+body > .wp-toc-toggle {{
+  all: revert;
+  position: fixed;
+  top: 0.75rem;
+  left: 0.75rem;
+  z-index: 51;
+  width: 2.4rem;
+  height: 2.4rem;
+  border: 1px solid #cfcfcf;
+  border-radius: 4px;
+  background: #ffffff;
+  color: #227842;
+  font-size: 1.2rem;
+  line-height: 1;
+  cursor: pointer;
+  display: none;
+  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.12);
+}}
+body > .wp-toc-backdrop {{
+  all: revert;
+  position: fixed;
+  inset: 0;
+  background: rgba(0, 0, 0, 0.35);
+  z-index: 49;
+  display: none;
+}}
+@media (min-width: 1100px) {{
+  /* Push the centered docutils column right so it never slides under
+     the rail. The blanket `body > *` rule already centers content with
+     huge calc() padding, so we just add a left margin to body. */
+  body {{ margin-left: 280px; }}
+  /* The uncloseai floating button is `position: fixed; left: ...`, so
+     it sits independent of body margin. No further adjustment. */
+}}
+@media (max-width: 1099px) {{
+  body > .wp-toc {{
+    transform: translateX(-100%);
+    transition: transform 0.2s ease-out;
+    width: min(85vw, 320px);
+    box-shadow: 2px 0 8px rgba(0, 0, 0, 0.12);
+  }}
+  body > .wp-toc.open {{ transform: translateX(0); }}
+  body > .wp-toc-toggle {{ display: block; }}
+  body > .wp-toc-backdrop.open {{ display: block; }}
+}}
 </style>
 <script>
 (function () {{
@@ -103,6 +219,113 @@ main img, section img {{
     }});
   }});
 }})();
+(function () {{
+  if (window.__wpToc) return;
+  window.__wpToc = true;
+  document.addEventListener("DOMContentLoaded", function () {{
+    var main = document.querySelector("main");
+    if (!main) return;
+    // Pick up only the top two heading levels — section-id <section>s
+    // that wrap <h2> (chapters) and <h3> (sections). Anything deeper
+    // creates noise in a left rail. Skip the doc title <h1> since the
+    // sidebar header already labels the doc.
+    var sections = main.querySelectorAll("section[id] > h2, section[id] > h3");
+    if (sections.length < 3) return;
+    var nav = document.createElement("nav");
+    nav.className = "wp-toc";
+    nav.setAttribute("aria-label", "Table of contents");
+    var title = document.createElement("p");
+    title.className = "wp-toc-title";
+    title.innerHTML = 'lumbda<span class="period" aria-hidden="true">.</span>';
+    nav.appendChild(title);
+    var list = document.createElement("ol");
+    var byId = {{}};
+    sections.forEach(function (h) {{
+      var sec = h.parentElement;
+      var id = sec.id;
+      if (!id) return;
+      var lvl = h.tagName === "H2" ? 2 : 3;
+      var li = document.createElement("li");
+      li.className = "lvl-" + lvl;
+      var a = document.createElement("a");
+      a.href = "#" + id;
+      a.textContent = h.textContent.trim();
+      li.appendChild(a);
+      list.appendChild(li);
+      byId[id] = a;
+    }});
+    nav.appendChild(list);
+    var backdrop = document.createElement("div");
+    backdrop.className = "wp-toc-backdrop";
+    var toggle = document.createElement("button");
+    toggle.className = "wp-toc-toggle";
+    toggle.setAttribute("aria-label", "Open table of contents");
+    toggle.textContent = "☰"; // hamburger
+    function close() {{
+      nav.classList.remove("open");
+      backdrop.classList.remove("open");
+    }}
+    function open() {{
+      nav.classList.add("open");
+      backdrop.classList.add("open");
+    }}
+    toggle.addEventListener("click", function () {{
+      if (nav.classList.contains("open")) close(); else open();
+    }});
+    backdrop.addEventListener("click", close);
+    // Auto-close after navigating from a link on narrow viewports.
+    nav.addEventListener("click", function (e) {{
+      if (e.target.tagName === "A" && window.innerWidth < 1100) close();
+    }});
+    document.body.insertBefore(nav, document.body.firstChild);
+    document.body.appendChild(backdrop);
+    document.body.appendChild(toggle);
+    // Active-section tracking. IntersectionObserver picks the
+    // highest-up section currently in view; falls back to a scroll
+    // handler when IO is unavailable (very old browsers).
+    var active = null;
+    function setActive(id) {{
+      if (active === id) return;
+      if (active && byId[active]) byId[active].classList.remove("active");
+      active = id;
+      if (byId[id]) {{
+        byId[id].classList.add("active");
+        // Keep the active link in view inside the rail.
+        var rect = byId[id].getBoundingClientRect();
+        var navRect = nav.getBoundingClientRect();
+        if (rect.top < navRect.top || rect.bottom > navRect.bottom) {{
+          byId[id].scrollIntoView({{ block: "nearest" }});
+        }}
+      }}
+    }}
+    if ("IntersectionObserver" in window) {{
+      var visible = new Set();
+      var io = new IntersectionObserver(function (entries) {{
+        entries.forEach(function (e) {{
+          if (e.isIntersecting) visible.add(e.target.id);
+          else visible.delete(e.target.id);
+        }});
+        // Pick the visible section that appears earliest in the doc.
+        var first = null;
+        sections.forEach(function (h) {{
+          var sid = h.parentElement.id;
+          if (visible.has(sid) && first === null) first = sid;
+        }});
+        if (first) setActive(first);
+      }}, {{ rootMargin: "-80px 0px -60% 0px", threshold: 0 }});
+      sections.forEach(function (h) {{ io.observe(h.parentElement); }});
+    }} else {{
+      window.addEventListener("scroll", function () {{
+        var y = window.scrollY + 100;
+        var current = null;
+        sections.forEach(function (h) {{
+          if (h.parentElement.offsetTop <= y) current = h.parentElement.id;
+        }});
+        if (current) setActive(current);
+      }}, {{ passive: true }});
+    }}
+  }});
+}})();
 </script>
 """
 
diff --git a/whitepaper/lumbda-whitepaper.html b/whitepaper/lumbda-whitepaper.html
index ab00008..86bac0c 100644
--- a/whitepaper/lumbda-whitepaper.html
+++ b/whitepaper/lumbda-whitepaper.html
@@ -863,6 +863,122 @@ main img, section img {
   object-fit: contain;
   box-shadow: 0 12px 48px rgba(0, 0, 0, 0.6);
 }
+/* Left-rail table of contents. Cancels the same docutils responsive.css
+   `body > *` blanket rule that broke the uncloseai button (padding /
+   margin / max-width / background / line-height) and then lays the
+   sidebar out as a fixed left rail on wide viewports. Below 1100px the
+   sidebar collapses behind a toggle button so it cannot crowd the
+   single-column reading flow on phones and narrow laptops. */
+body > .wp-toc {
+  all: revert;
+  position: fixed;
+  top: 0;
+  left: 0;
+  bottom: 0;
+  width: 280px;
+  padding: 1.25rem 1rem 1.25rem 1.5rem;
+  margin: 0;
+  background: #fafafa;
+  border-right: 1px solid #e5e5e5;
+  overflow-y: auto;
+  overflow-x: hidden;
+  z-index: 50;
+  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica,
+               Arial, sans-serif;
+  font-size: 0.82rem;
+  line-height: 1.4;
+  box-sizing: border-box;
+}
+.wp-toc-title {
+  font-family: 'chunkfive', Georgia, serif;
+  font-size: 1.15rem;
+  margin: 0 0 0.6rem 0;
+  color: #227842;
+  letter-spacing: 0.02em;
+}
+.wp-toc-title .period { color: #227842; }
+.wp-toc ol {
+  list-style: none;
+  padding: 0;
+  margin: 0;
+}
+.wp-toc li {
+  margin: 0;
+}
+.wp-toc a {
+  display: block;
+  padding: 0.22rem 0.4rem;
+  color: #333;
+  text-decoration: none;
+  border-left: 2px solid transparent;
+  border-radius: 0 3px 3px 0;
+  word-wrap: break-word;
+}
+.wp-toc a:hover {
+  background: #efefef;
+  color: #000;
+}
+.wp-toc a.active {
+  background: #e8f1ec;
+  color: #155c30;
+  border-left-color: #227842;
+  font-weight: 600;
+}
+.wp-toc li.lvl-3 a {
+  padding-left: 1.2rem;
+  font-size: 0.78rem;
+  color: #555;
+}
+.wp-toc li.lvl-3 a.active {
+  color: #155c30;
+}
+/* Toggle button — hidden on wide viewports, shown when the sidebar
+   collapses. Same `all: revert` trick so docutils does not stretch it. */
+body > .wp-toc-toggle {
+  all: revert;
+  position: fixed;
+  top: 0.75rem;
+  left: 0.75rem;
+  z-index: 51;
+  width: 2.4rem;
+  height: 2.4rem;
+  border: 1px solid #cfcfcf;
+  border-radius: 4px;
+  background: #ffffff;
+  color: #227842;
+  font-size: 1.2rem;
+  line-height: 1;
+  cursor: pointer;
+  display: none;
+  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.12);
+}
+body > .wp-toc-backdrop {
+  all: revert;
+  position: fixed;
+  inset: 0;
+  background: rgba(0, 0, 0, 0.35);
+  z-index: 49;
+  display: none;
+}
+@media (min-width: 1100px) {
+  /* Push the centered docutils column right so it never slides under
+     the rail. The blanket `body > *` rule already centers content with
+     huge calc() padding, so we just add a left margin to body. */
+  body { margin-left: 280px; }
+  /* The uncloseai floating button is `position: fixed; left: ...`, so
+     it sits independent of body margin. No further adjustment. */
+}
+@media (max-width: 1099px) {
+  body > .wp-toc {
+    transform: translateX(-100%);
+    transition: transform 0.2s ease-out;
+    width: min(85vw, 320px);
+    box-shadow: 2px 0 8px rgba(0, 0, 0, 0.12);
+  }
+  body > .wp-toc.open { transform: translateX(0); }
+  body > .wp-toc-toggle { display: block; }
+  body > .wp-toc-backdrop.open { display: block; }
+}
 </style>
 <script>
 (function () {
@@ -890,6 +1006,113 @@ main img, section img {
     });
   });
 })();
+(function () {
+  if (window.__wpToc) return;
+  window.__wpToc = true;
+  document.addEventListener("DOMContentLoaded", function () {
+    var main = document.querySelector("main");
+    if (!main) return;
+    // Pick up only the top two heading levels — section-id <section>s
+    // that wrap <h2> (chapters) and <h3> (sections). Anything deeper
+    // creates noise in a left rail. Skip the doc title <h1> since the
+    // sidebar header already labels the doc.
+    var sections = main.querySelectorAll("section[id] > h2, section[id] > h3");
+    if (sections.length < 3) return;
+    var nav = document.createElement("nav");
+    nav.className = "wp-toc";
+    nav.setAttribute("aria-label", "Table of contents");
+    var title = document.createElement("p");
+    title.className = "wp-toc-title";
+    title.innerHTML = 'lumbda<span class="period" aria-hidden="true">.</span>';
+    nav.appendChild(title);
+    var list = document.createElement("ol");
+    var byId = {};
+    sections.forEach(function (h) {
+      var sec = h.parentElement;
+      var id = sec.id;
+      if (!id) return;
+      var lvl = h.tagName === "H2" ? 2 : 3;
+      var li = document.createElement("li");
+      li.className = "lvl-" + lvl;
+      var a = document.createElement("a");
+      a.href = "#" + id;
+      a.textContent = h.textContent.trim();
+      li.appendChild(a);
+      list.appendChild(li);
+      byId[id] = a;
+    });
+    nav.appendChild(list);
+    var backdrop = document.createElement("div");
+    backdrop.className = "wp-toc-backdrop";
+    var toggle = document.createElement("button");
+    toggle.className = "wp-toc-toggle";
+    toggle.setAttribute("aria-label", "Open table of contents");
+    toggle.textContent = "☰"; // hamburger
+    function close() {
+      nav.classList.remove("open");
+      backdrop.classList.remove("open");
+    }
+    function open() {
+      nav.classList.add("open");
+      backdrop.classList.add("open");
+    }
+    toggle.addEventListener("click", function () {
+      if (nav.classList.contains("open")) close(); else open();
+    });
+    backdrop.addEventListener("click", close);
+    // Auto-close after navigating from a link on narrow viewports.
+    nav.addEventListener("click", function (e) {
+      if (e.target.tagName === "A" && window.innerWidth < 1100) close();
+    });
+    document.body.insertBefore(nav, document.body.firstChild);
+    document.body.appendChild(backdrop);
+    document.body.appendChild(toggle);
+    // Active-section tracking. IntersectionObserver picks the
+    // highest-up section currently in view; falls back to a scroll
+    // handler when IO is unavailable (very old browsers).
+    var active = null;
+    function setActive(id) {
+      if (active === id) return;
+      if (active && byId[active]) byId[active].classList.remove("active");
+      active = id;
+      if (byId[id]) {
+        byId[id].classList.add("active");
+        // Keep the active link in view inside the rail.
+        var rect = byId[id].getBoundingClientRect();
+        var navRect = nav.getBoundingClientRect();
+        if (rect.top < navRect.top || rect.bottom > navRect.bottom) {
+          byId[id].scrollIntoView({ block: "nearest" });
+        }
+      }
+    }
+    if ("IntersectionObserver" in window) {
+      var visible = new Set();
+      var io = new IntersectionObserver(function (entries) {
+        entries.forEach(function (e) {
+          if (e.isIntersecting) visible.add(e.target.id);
+          else visible.delete(e.target.id);
+        });
+        // Pick the visible section that appears earliest in the doc.
+        var first = null;
+        sections.forEach(function (h) {
+          var sid = h.parentElement.id;
+          if (visible.has(sid) && first === null) first = sid;
+        });
+        if (first) setActive(first);
+      }, { rootMargin: "-80px 0px -60% 0px", threshold: 0 });
+      sections.forEach(function (h) { io.observe(h.parentElement); });
+    } else {
+      window.addEventListener("scroll", function () {
+        var y = window.scrollY + 100;
+        var current = null;
+        sections.forEach(function (h) {
+          if (h.parentElement.offsetTop <= y) current = h.parentElement.id;
+        });
+        if (current) setActive(current);
+      }, { passive: true });
+    }
+  });
+})();
 </script>
 </head>
 <body>