diff --git a/assets/diary/diary-day.html b/assets/diary/diary-day.html
index 834e260..05c4b84 100644
--- a/assets/diary/diary-day.html
+++ b/assets/diary/diary-day.html
@@ -1,5 +1,5 @@
 {{if .Photos}}
-<div class="diary-photo-grid">
+<div class="photo-grid">
   {{range .Photos}}
   <a href="{{.URL}}" target="_blank"><img src="{{.URL}}" alt="{{.Name}}" loading="lazy"></a>
   {{end}}
diff --git a/assets/diary/diary-month.html b/assets/diary/diary-month.html
index 526d325..7ef6988 100644
--- a/assets/diary/diary-month.html
+++ b/assets/diary/diary-month.html
@@ -1,16 +1,14 @@
 {{range .Days}}
-<div class="diary-section">
-  <h2>
-    {{if .URL}}<a href="{{.URL}}">{{.Heading}}</a>{{else}}{{.Heading}}{{end}}
-    {{if .EditURL}}<a href="{{.EditURL}}" class="btn btn-small">edit</a>{{end}}
-  </h2>
-  {{if .Content}}<div class="content">{{.Content}}</div>{{end}}
-  {{if .Photos}}
-  <div class="diary-photo-grid">
-    {{range .Photos}}
-    <a href="{{.URL}}" target="_blank"><img src="{{.URL}}" alt="{{.Name}}" loading="lazy"></a>
-    {{end}}
-  </div>
+<h2 id="{{.ID}}">
+  {{if .URL}}<a href="{{.URL}}">{{.Heading}}</a>{{else}}{{.Heading}}{{end}}
+  {{if .EditURL}}<a href="{{.EditURL}}" class="btn btn-small">edit</a>{{end}}
+</h2>
+{{if .Content}}{{.Content}}{{end}}
+{{if .Photos}}
+<div class="photo-grid">
+  {{range .Photos}}
+  <a href="{{.URL}}" target="_blank"><img src="{{.URL}}" alt="{{.Name}}" loading="lazy"></a>
   {{end}}
 </div>
 {{end}}
+{{end}}
diff --git a/assets/diary/diary-year.html b/assets/diary/diary-year.html
index 8e0cc17..263677f 100644
--- a/assets/diary/diary-year.html
+++ b/assets/diary/diary-year.html
@@ -1,8 +1,7 @@
+<h2 id="months">Months</h2>
 {{range .Months}}
-<div class="diary-section">
-  <h2 class="diary-heading">
-    <a href="{{.URL}}">{{.Name}}</a>
-    {{if .PhotoCount}}<span class="diary-photo-count">({{.PhotoCount}} photos)</span>{{end}}
-  </h2>
-</div>
+<h3 id="{{.ID}}">
+  <a href="{{.URL}}">{{.Name}}</a>
+  {{if .PhotoCount}}<span class="muted">({{.PhotoCount}} photos)</span>{{end}}
+</h3>
 {{end}}
diff --git a/assets/page.html b/assets/page.html
index 6176607..5f28b1f 100644
--- a/assets/page.html
+++ b/assets/page.html
@@ -61,10 +61,11 @@
             <div class="content">{{.Content}}</div>
             {{end}}
             {{if .SpecialContent}}
-            <div class="diary">{{.SpecialContent}}</div>
+            <div class="content">{{.SpecialContent}}</div>
             {{end}}
             {{if or .Content .SpecialContent}}
             <script src="/_/content.js"></script>
+            <script src="/_/toc.js"></script>
             {{end}}
             {{if .Content}}
             <script src="/_/sections.js"></script>
diff --git a/assets/sections.js b/assets/sections.js
index 10382e2..09b05c3 100644
--- a/assets/sections.js
+++ b/assets/sections.js
@@ -9,7 +9,7 @@
     headings.forEach(function (h, i) {
         var a = document.createElement('a');
         a.href = '?edit&section=' + (i + 1);
-        a.className = 'btn btn-small section-edit';
+        a.className = 'btn btn-small';
         a.textContent = 'edit';
         h.appendChild(a);
     });
diff --git a/assets/style.css b/assets/style.css
index a7fae4b..7e78eec 100644
--- a/assets/style.css
+++ b/assets/style.css
@@ -325,59 +325,32 @@ textarea {
     box-sizing: border-box;
 }
 
-/* === Diary views === */
-.diary-section {
-    margin: 2rem 0;
-    padding-top: 1.5rem;
-    border-top: 1px dashed var(--secondary);
-}
-
-.diary-section:first-child {
-    border-top: none;
-    padding-top: 0;
-    margin-top: 0;
-}
-
-.diary-section h2 {
-    font-size: 1.2rem;
-    color: var(--text);
-    margin-bottom: 0.75rem;
-    font-weight: normal;
-}
-
-.diary-photo-count {
+/* === Muted text === */
+.muted {
     color: var(--text-muted);
     font-size: 0.85rem;
 }
 
-.diary-photo-grid {
+/* === Photo grid === */
+.photo-grid {
     display: grid;
     grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
     gap: 0.4rem;
     margin-top: 0.75rem;
 }
 
-.diary-photo-grid a {
+.photo-grid a {
     display: block;
     line-height: 0;
 }
 
-.diary-photo-grid img {
+.photo-grid img {
     width: 100%;
     height: 140px;
     object-fit: cover;
     display: block;
 }
 
-.diary-section .content {
-    margin-bottom: 0.75rem;
-}
-
-/* === Section edit links === */
-.section-edit {
-    margin-left: 0.75rem;
-}
-
 /* === Empty state === */
 .empty {
     padding: 1rem;
@@ -405,7 +378,99 @@ hr {
     background: var(--primary-hover);
 }
 
+/* === Table of contents === */
+.toc {
+    position: fixed;
+    top: 1rem;
+    right: 1rem;
+    width: 14rem;
+    max-height: calc(100vh - 2rem);
+    overflow-y: auto;
+    border: 1px solid var(--secondary);
+    background: var(--bg);
+    padding: 0.5rem 0.75rem;
+    font-size: 0.85rem;
+}
+
+.toc-header {
+    font-size: 0.75rem;
+    text-transform: uppercase;
+    letter-spacing: 0.05em;
+    color: var(--text-muted);
+    border-bottom: 1px dashed var(--secondary);
+    padding-bottom: 0.25rem;
+    margin-bottom: 0.4rem;
+}
+
+.toc ul {
+    list-style: none;
+    margin: 0;
+    padding: 0;
+}
+
+.toc li {
+    margin: 0.15rem 0;
+}
+
+.toc a {
+    color: var(--link);
+    display: block;
+    overflow: hidden;
+    text-overflow: ellipsis;
+    white-space: nowrap;
+}
+.toc a:hover {
+    color: var(--link-hover);
+}
+
+.toc-h2 {
+    padding-left: 0.8rem;
+}
+.toc-h3 {
+    padding-left: 1.6rem;
+}
+
+.toc-toggle {
+    display: none;
+}
+
 /* === Responsive === */
+@media (max-width: 1100px) {
+    .toc-toggle {
+        display: block;
+        background: none;
+        border: 1px solid var(--secondary);
+        color: var(--text);
+        font: inherit;
+        font-size: 0.8rem;
+        text-transform: uppercase;
+        letter-spacing: 0.05em;
+        cursor: pointer;
+        padding: 0.4rem 0.75rem;
+        margin: 1rem auto;
+        width: calc(100% - 2rem);
+        max-width: 860px;
+    }
+    .toc-toggle::before {
+        content: "▸ ";
+        color: var(--secondary);
+    }
+    .toc-toggle[aria-expanded="true"]::before {
+        content: "▾ ";
+    }
+    .toc {
+        position: static;
+        display: none;
+        width: calc(100% - 2rem);
+        max-width: 860px;
+        margin: 0 auto 1rem;
+        max-height: none;
+    }
+    .toc.is-open {
+        display: block;
+    }
+}
+
 @media (max-width: 600px) {
     header {
         padding: 0.5rem 0.75rem;
@@ -416,4 +481,8 @@ hr {
     textarea {
         min-height: 50vh;
     }
+    .toc-toggle,
+    .toc.is-open {
+        width: calc(100% - 1.5rem);
+    }
 }
diff --git a/assets/toc.js b/assets/toc.js
new file mode 100644
index 0000000..c797477
--- /dev/null
+++ b/assets/toc.js
@@ -0,0 +1,57 @@
+(function () {
+  var content = document.querySelector("main");
+  if (!content) return;
+
+  var headings = content.querySelectorAll("h1, h2, h3");
+  if (headings.length < 2) return;
+
+  var nav = document.createElement("nav");
+  nav.className = "toc";
+
+  var header = document.createElement("div");
+  header.className = "toc-header";
+  header.textContent = "Contents";
+  nav.appendChild(header);
+
+  var list = document.createElement("ul");
+  headings.forEach(function (h) {
+    if (!h.id) return;
+    var li = document.createElement("li");
+    li.className = "toc-" + h.tagName.toLowerCase();
+    var a = document.createElement("a");
+    a.href = "#" + h.id;
+    a.textContent = h.textContent;
+    li.appendChild(a);
+    list.appendChild(li);
+  });
+  nav.appendChild(list);
+
+  var toggle = document.createElement("button");
+  toggle.type = "button";
+  toggle.className = "toc-toggle";
+  toggle.textContent = "Contents";
+  toggle.setAttribute("aria-expanded", "false");
+  toggle.addEventListener("click", function () {
+    var open = nav.classList.toggle("is-open");
+    toggle.setAttribute("aria-expanded", open ? "true" : "false");
+  });
+
+  var main = document.querySelector("main");
+  if (main) {
+    main.parentNode.insertBefore(toggle, main);
+    main.parentNode.insertBefore(nav, main);
+  } else {
+    document.body.appendChild(toggle);
+    document.body.appendChild(nav);
+  }
+
+  var pageHeader = document.querySelector("header");
+  function updateTop() {
+    if (!pageHeader || getComputedStyle(nav).position !== "fixed") return;
+    var rect = pageHeader.getBoundingClientRect();
+    nav.style.top = Math.max(8, rect.bottom + 8) + "px";
+  }
+  window.addEventListener("scroll", updateTop, { passive: true });
+  window.addEventListener("resize", updateTop);
+  updateTop();
+})();
diff --git a/diary.go b/diary.go
index 9b22306..5c85c29 100644
--- a/diary.go
+++ b/diary.go
@@ -69,12 +69,14 @@ type diaryPhoto struct {
 }
 
 type diaryMonthSummary struct {
+	ID         string
 	Name       string
 	URL        string
 	PhotoCount int
 }
 
 type diaryDaySection struct {
+	ID      string
 	Heading string
 	URL     string
 	EditURL string
@@ -82,7 +84,10 @@ type diaryDaySection struct {
 	Photos  []diaryPhoto
 }
 
-type diaryYearData struct{ Months []diaryMonthSummary }
+type diaryYearData struct {
+	Months []diaryMonthSummary
+	Year   int
+}
 type diaryMonthData struct{ Days []diaryDaySection }
 type diaryDayData struct{ Photos []diaryPhoto }
 
@@ -191,6 +196,7 @@ func renderDiaryYear(fsPath, urlPath string) template.HTML {
 		}
 		monthDate := time.Date(year, time.Month(monthNum), 1, 0, 0, 0, 0, time.UTC)
 		months = append(months, diaryMonthSummary{
+			ID:         monthDate.Format("2006-01"),
 			Name:       monthDate.Format("January 2006"),
 			URL:        path.Join(urlPath, e.Name()) + "/",
 			PhotoCount: count,
@@ -198,7 +204,7 @@ func renderDiaryYear(fsPath, urlPath string) template.HTML {
 	}
 
 	var buf bytes.Buffer
-	if err := diaryYearTmpl.Execute(&buf, diaryYearData{Months: months}); err != nil {
+	if err := diaryYearTmpl.Execute(&buf, diaryYearData{Months: months, Year: year}); err != nil {
 		log.Printf("diary year template: %v", err)
 		return ""
 	}
@@ -280,6 +286,7 @@ func renderDiaryMonth(fsPath, urlPath string) template.HTML {
 		}
 
 		sections = append(sections, diaryDaySection{
+			ID:      date.Format("2006-01-02"),
 			Heading: heading,
 			URL:     dayURL,
 			EditURL: dayURL + "?edit",