From f145b83f68731d6f31c3e1b1de59fd7be8f62001 Mon Sep 17 00:00:00 2001
From: Seongho Bae <me@seonghobae.me>
Date: Sat, 22 Aug 2026 02:18:46 +0900
Subject: [PATCH 1/5] fix(frontend): preserve structured footnote roles

---
 frontend/src/postBodyDisplay.test.ts | 16 +++++++++
 frontend/src/postBodyDisplay.ts      | 51 +++++++++++++++++++++++++---
 2 files changed, 62 insertions(+), 5 deletions(-)

diff --git a/frontend/src/postBodyDisplay.test.ts b/frontend/src/postBodyDisplay.test.ts
index 07ca9514d..52c8c65eb 100644
--- a/frontend/src/postBodyDisplay.test.ts
+++ b/frontend/src/postBodyDisplay.test.ts
@@ -61,6 +61,22 @@ describe("splitPostBody", () => {
     ]);
   });
 
+  it("labels HTML, Word, and OOXML footnotes in the fallback renderer", () => {
+    expect(
+      splitPostBody(
+        '<p>Body text</p>' +
+          '<ol class="footnotes"><li id="fn1"><p>HTML footnote body</p></li></ol>' +
+          '<p class="MsoFootnoteText"><a href="#_ftnref1"><sup>1</sup></a> Word footnote body</p>' +
+          "<w:footnote w:id='1'><w:p>OOXML footnote body</w:p></w:footnote>",
+      ),
+    ).toEqual([
+      { kind: "text", text: "Body text" },
+      { kind: "text", text: "HTML footnote body", role: "footnote" },
+      { kind: "text", text: "^1 Word footnote body", role: "footnote" },
+      { kind: "text", text: "OOXML footnote body", role: "footnote" },
+    ]);
+  });
+
   it("leaves a plain-text post unchanged so existing popups keep their wording", () => {
     expect(splitPostBody("The full body text.")).toEqual([
       { kind: "text", text: "The full body text." },
diff --git a/frontend/src/postBodyDisplay.ts b/frontend/src/postBodyDisplay.ts
index 919e8c0ca..7e7c4b39c 100644
--- a/frontend/src/postBodyDisplay.ts
+++ b/frontend/src/postBodyDisplay.ts
@@ -24,10 +24,47 @@ const FOOTNOTE_START = /^\s*[*†‡](?=\S)/;
 const INDENT_MARKER = "\u0001lw-indent:";
 const INDENT_MARKER_END = "\u0002";
 const INDENT_MARKER_PATTERN = /lw-indent:(\d+)/g;
+const FOOTNOTE_MARKER = "\u0001lw-footnote\u0002";
+const FOOTNOTE_MARKER_PATTERN = new RegExp(FOOTNOTE_MARKER, "g");
+
+function markFootnoteTags(markup: string): string {
+  let footnoteDepth = 0;
+  return markup.replace(HTML_TAG, (tag) => {
+    const match = tag.match(/^<\s*(\/?)\s*([a-z][a-z0-9:-]*)\b/i);
+    if (!match) return tag;
+    const closing = Boolean(match[1]);
+    const name = match[2].toLowerCase();
+    const hasFootnoteLabel = /\b(?:footnotes?|endnotes?|msofootnotetext|msoendnotetext)\b/i.test(tag);
+    const isContainer =
+      (name === "ol" || name === "ul") && hasFootnoteLabel;
+    const isWordParagraph =
+      name === "p" && hasFootnoteLabel;
+    const isOoxmlContainer = name === "w:footnote" || name === "w:endnote";
+
+    if (closing) {
+      if (isOoxmlContainer || isContainer) {
+        footnoteDepth = Math.max(0, footnoteDepth - 1);
+      }
+      return tag;
+    }
+    if (isOoxmlContainer || isContainer) {
+      if (!/\/\s*>$/.test(tag)) footnoteDepth += 1;
+      return `${tag}${FOOTNOTE_MARKER}`;
+    }
+    if (
+      isWordParagraph ||
+      (footnoteDepth > 0 && (name === "li" || name === "p" || name === "w:p"))
+    ) {
+      return `${tag}${FOOTNOTE_MARKER}`;
+    }
+    return tag;
+  });
+}
 
 function stripIndentMarkers(value: string): string {
   return value
     .replace(INDENT_MARKER_PATTERN, "")
+    .replace(FOOTNOTE_MARKER_PATTERN, "")
     .split(String.fromCharCode(1))
     .join("")
     .split(String.fromCharCode(2))
@@ -90,7 +127,7 @@ function indentMarker(width: number): string {
 }
 
 function stripHtmlTags(text: string): string {
-  text = text.replace(/<sup[^>]*>(.*?)<\/sup>/gi, "^$1");
+  text = markFootnoteTags(text).replace(/<sup[^>]*>(.*?)<\/sup>/gi, "^$1");
   const withBoundaries = text
     .replace(BREAK_TAG, "\n")
     .replace(BLOCK_TAG, (tag) => {
@@ -98,9 +135,10 @@ function stripHtmlTags(text: string): string {
       return `\n\n${indentMarker(declaredIndentWidth(tag))}`;
     })
     .replace(WORD_INDENT_TAG, (tag) => indentMarker(declaredIndentWidth(tag)));
-  const withoutTags = withBoundaries.replace(HTML_TAG, (tag) =>
-    /^<\/?w:/i.test(tag) ? "" : " ",
-  );
+  const withoutTags = withBoundaries.replace(HTML_TAG, (tag) => {
+    if (/^<\/?(?:a|w:)/i.test(tag)) return "";
+    return " ";
+  });
   const decoded = decodeHtmlEntities(withoutTags);
   return decoded
     .split("\n")
@@ -200,6 +238,7 @@ function isDecodableBase64(raw: string): boolean {
 function pushText(segments: PostBodySegment[], raw: string, indentUnit: number): void {
   const text = stripHtmlTags(raw);
   for (const paragraph of splitSemanticParagraphs(text)) {
+    const isMarkedFootnote = paragraph.includes(FOOTNOTE_MARKER);
     const indentLevel = indentationLevel(paragraph, indentUnit);
     const normalized = stripIndentMarkers(paragraph)
       .replace(/^[ \t]+/, "")
@@ -209,7 +248,9 @@ function pushText(segments: PostBodySegment[], raw: string, indentUnit: number):
         kind: "text",
         text: normalized,
         ...(indentLevel > 0 ? { indentLevel } : {}),
-        ...(FOOTNOTE_START.test(normalized) ? { role: "footnote" as const } : {}),
+        ...(isMarkedFootnote || FOOTNOTE_START.test(normalized)
+          ? { role: "footnote" as const }
+          : {}),
       });
     }
   }

From 81cd12fcfe24fd8073ef86b96a29035a6d1cec23 Mon Sep 17 00:00:00 2001
From: Seongho Bae <me@seonghobae.me>
Date: Sat, 22 Aug 2026 02:29:58 +0900
Subject: [PATCH 2/5] fix(frontend): close HTML footnote containers reliably

---
 frontend/src/postBodyDisplay.test.ts | 11 +++++++++++
 frontend/src/postBodyDisplay.ts      | 20 ++++++++++++++++----
 2 files changed, 27 insertions(+), 4 deletions(-)

diff --git a/frontend/src/postBodyDisplay.test.ts b/frontend/src/postBodyDisplay.test.ts
index 52c8c65eb..71b056e75 100644
--- a/frontend/src/postBodyDisplay.test.ts
+++ b/frontend/src/postBodyDisplay.test.ts
@@ -77,6 +77,17 @@ describe("splitPostBody", () => {
     ]);
   });
 
+  it("stops labeling ordinary content after an HTML footnote list", () => {
+    expect(
+      splitPostBody(
+        '<ol class="footnotes"><li>HTML footnote body</li></ol><p>Ordinary body after footnotes</p>',
+      ),
+    ).toEqual([
+      { kind: "text", text: "HTML footnote body", role: "footnote" },
+      { kind: "text", text: "Ordinary body after footnotes" },
+    ]);
+  });
+
   it("leaves a plain-text post unchanged so existing popups keep their wording", () => {
     expect(splitPostBody("The full body text.")).toEqual([
       { kind: "text", text: "The full body text." },
diff --git a/frontend/src/postBodyDisplay.ts b/frontend/src/postBodyDisplay.ts
index 7e7c4b39c..a22de0bef 100644
--- a/frontend/src/postBodyDisplay.ts
+++ b/frontend/src/postBodyDisplay.ts
@@ -29,6 +29,8 @@ const FOOTNOTE_MARKER_PATTERN = new RegExp(FOOTNOTE_MARKER, "g");
 
 function markFootnoteTags(markup: string): string {
   let footnoteDepth = 0;
+  const openTags: Array<{ name: string; isFootnote: boolean }> = [];
+  const voidTags = new Set(["area", "base", "br", "col", "embed", "hr", "img", "input", "link", "meta", "param", "source", "track", "w:br"]);
   return markup.replace(HTML_TAG, (tag) => {
     const match = tag.match(/^<\s*(\/?)\s*([a-z][a-z0-9:-]*)\b/i);
     if (!match) return tag;
@@ -42,13 +44,23 @@ function markFootnoteTags(markup: string): string {
     const isOoxmlContainer = name === "w:footnote" || name === "w:endnote";
 
     if (closing) {
-      if (isOoxmlContainer || isContainer) {
-        footnoteDepth = Math.max(0, footnoteDepth - 1);
+      const matchingIndex = openTags.map((entry) => entry.name).lastIndexOf(name);
+      if (matchingIndex >= 0) {
+        const closedTags = openTags.splice(matchingIndex);
+        footnoteDepth = Math.max(
+          0,
+          footnoteDepth - closedTags.filter((entry) => entry.isFootnote).length,
+        );
       }
       return tag;
     }
-    if (isOoxmlContainer || isContainer) {
-      if (!/\/\s*>$/.test(tag)) footnoteDepth += 1;
+    const selfClosing = /\/\s*>$/.test(tag) || voidTags.has(name);
+    const opensFootnote = isOoxmlContainer || isContainer;
+    if (!selfClosing) {
+      openTags.push({ name, isFootnote: opensFootnote });
+    }
+    if (opensFootnote) {
+      if (!selfClosing) footnoteDepth += 1;
       return `${tag}${FOOTNOTE_MARKER}`;
     }
     if (

From 146cc56e07db9479ab8dba93aedb0ffd06d2e795 Mon Sep 17 00:00:00 2001
From: Seongho Bae <me@seonghobae.me>
Date: Sat, 22 Aug 2026 02:31:05 +0900
Subject: [PATCH 3/5] fix: hide empty footnote markers

---
 frontend/src/postBodyDisplay.test.ts | 4 ++++
 frontend/src/postBodyDisplay.ts      | 2 +-
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/frontend/src/postBodyDisplay.test.ts b/frontend/src/postBodyDisplay.test.ts
index 71b056e75..bd28646d6 100644
--- a/frontend/src/postBodyDisplay.test.ts
+++ b/frontend/src/postBodyDisplay.test.ts
@@ -88,6 +88,10 @@ describe("splitPostBody", () => {
     ]);
   });
 
+  it("does not expose control markers for an empty footnote container", () => {
+    expect(splitPostBody('<ol class="footnotes"></ol>')).toEqual([{ kind: "text", text: "" }]);
+  });
+
   it("leaves a plain-text post unchanged so existing popups keep their wording", () => {
     expect(splitPostBody("The full body text.")).toEqual([
       { kind: "text", text: "The full body text." },
diff --git a/frontend/src/postBodyDisplay.ts b/frontend/src/postBodyDisplay.ts
index a22de0bef..16cfb1004 100644
--- a/frontend/src/postBodyDisplay.ts
+++ b/frontend/src/postBodyDisplay.ts
@@ -296,7 +296,7 @@ export function splitPostBody(body: string): PostBodySegment[] {
   }
   pushText(segments, body.slice(lastIndex), indentUnit);
   if (segments.length === 0) {
-    return [{ kind: "text", text: stripHtmlTags(body) }];
+    return [{ kind: "text", text: stripIndentMarkers(stripHtmlTags(body)) }];
   }
   return segments;
 }

From 1b680a27e6eaca544f1d99512e31220278c43110 Mon Sep 17 00:00:00 2001
From: Seongho Bae <me@seonghobae.me>
Date: Sat, 22 Aug 2026 03:00:46 +0900
Subject: [PATCH 4/5] fix(frontend): bound footnote and anchor tag detection

---
 frontend/src/postBodyDisplay.test.ts | 18 ++++++++++++++++++
 frontend/src/postBodyDisplay.ts      |  7 +++++--
 2 files changed, 23 insertions(+), 2 deletions(-)

diff --git a/frontend/src/postBodyDisplay.test.ts b/frontend/src/postBodyDisplay.test.ts
index bd28646d6..29bad7fa3 100644
--- a/frontend/src/postBodyDisplay.test.ts
+++ b/frontend/src/postBodyDisplay.test.ts
@@ -92,6 +92,24 @@ describe("splitPostBody", () => {
     expect(splitPostBody('<ol class="footnotes"></ol>')).toEqual([{ kind: "text", text: "" }]);
   });
 
+  it("does not infer footnotes from unrelated attribute values", () => {
+    expect(
+      splitPostBody(
+        '<ol data-purpose="footnotes"><li>Ordinary list</li></ol>' +
+          '<p data-purpose="footnote">Ordinary paragraph</p>',
+      ),
+    ).toEqual([
+      { kind: "text", text: "Ordinary list" },
+      { kind: "text", text: "Ordinary paragraph" },
+    ]);
+  });
+
+  it("keeps text boundaries for tags whose names start with a", () => {
+    expect(splitPostBody('<p>Alpha<abbr title="expanded">Beta</abbr>Gamma</p>')).toEqual([
+      { kind: "text", text: "Alpha Beta Gamma" },
+    ]);
+  });
+
   it("leaves a plain-text post unchanged so existing popups keep their wording", () => {
     expect(splitPostBody("The full body text.")).toEqual([
       { kind: "text", text: "The full body text." },
diff --git a/frontend/src/postBodyDisplay.ts b/frontend/src/postBodyDisplay.ts
index 16cfb1004..a3eeeb9fd 100644
--- a/frontend/src/postBodyDisplay.ts
+++ b/frontend/src/postBodyDisplay.ts
@@ -36,7 +36,10 @@ function markFootnoteTags(markup: string): string {
     if (!match) return tag;
     const closing = Boolean(match[1]);
     const name = match[2].toLowerCase();
-    const hasFootnoteLabel = /\b(?:footnotes?|endnotes?|msofootnotetext|msoendnotetext)\b/i.test(tag);
+    const hasFootnoteLabel = [...tag.matchAll(/\b(?:class|role)\s*=\s*(["'])(.*?)\1/gi)].some(
+      (attribute) =>
+        /\b(?:footnotes?|endnotes?|msofootnotetext|msoendnotetext)\b/i.test(attribute[2]),
+    );
     const isContainer =
       (name === "ol" || name === "ul") && hasFootnoteLabel;
     const isWordParagraph =
@@ -148,7 +151,7 @@ function stripHtmlTags(text: string): string {
     })
     .replace(WORD_INDENT_TAG, (tag) => indentMarker(declaredIndentWidth(tag)));
   const withoutTags = withBoundaries.replace(HTML_TAG, (tag) => {
-    if (/^<\/?(?:a|w:)/i.test(tag)) return "";
+    if (/^<\/?(?:a\b|w:)/i.test(tag)) return "";
     return " ";
   });
   const decoded = decodeHtmlEntities(withoutTags);

From caea21be9e3485086ae3967fe5e6d23199b5459e Mon Sep 17 00:00:00 2001
From: Seongho Bae <me@seonghobae.me>
Date: Sat, 22 Aug 2026 03:15:58 +0900
Subject: [PATCH 5/5] fix(frontend): recognize wrapped footnote lists

---
 frontend/src/postBodyDisplay.test.ts | 14 ++++++++++++++
 frontend/src/postBodyDisplay.ts      |  2 +-
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/frontend/src/postBodyDisplay.test.ts b/frontend/src/postBodyDisplay.test.ts
index 29bad7fa3..bde6bd936 100644
--- a/frontend/src/postBodyDisplay.test.ts
+++ b/frontend/src/postBodyDisplay.test.ts
@@ -88,6 +88,20 @@ describe("splitPostBody", () => {
     ]);
   });
 
+  it("labels footnotes inside a labeled wrapper around an HTML list", () => {
+    expect(
+      splitPostBody(
+        '<p>Body text</p>' +
+          '<div class="footnotes"><ol><li><p>Wrapped footnote body</p></li></ol></div>' +
+          "<p>Ordinary body after footnotes</p>",
+      ),
+    ).toEqual([
+      { kind: "text", text: "Body text" },
+      { kind: "text", text: "Wrapped footnote body", role: "footnote" },
+      { kind: "text", text: "Ordinary body after footnotes" },
+    ]);
+  });
+
   it("does not expose control markers for an empty footnote container", () => {
     expect(splitPostBody('<ol class="footnotes"></ol>')).toEqual([{ kind: "text", text: "" }]);
   });
diff --git a/frontend/src/postBodyDisplay.ts b/frontend/src/postBodyDisplay.ts
index a3eeeb9fd..51c040f17 100644
--- a/frontend/src/postBodyDisplay.ts
+++ b/frontend/src/postBodyDisplay.ts
@@ -41,7 +41,7 @@ function markFootnoteTags(markup: string): string {
         /\b(?:footnotes?|endnotes?|msofootnotetext|msoendnotetext)\b/i.test(attribute[2]),
     );
     const isContainer =
-      (name === "ol" || name === "ul") && hasFootnoteLabel;
+      hasFootnoteLabel && (name === "div" || name === "ol" || name === "ul");
     const isWordParagraph =
       name === "p" && hasFootnoteLabel;
     const isOoxmlContainer = name === "w:footnote" || name === "w:endnote";