cursor and fontissue

engine/CMakeLists.txt

@@ -29,6 +29,8 @@ add_library(pdfengine OBJECT
     src/fonts/pdf_fonts/font_fallback.cpp
     src/fonts/pdf_fonts/font_subset.cpp
     src/fonts/pdf_fonts/font_cmap_builder.cpp
+    src/fonts/pdf_fonts/font_validator.cpp
+    src/fonts/pdf_fonts/font_extraction_service.cpp
     src/fonts/pdf_fonts/embedded_font_reconstructor.cpp
     src/fonts/pdf_fonts/encoding/encoding.cpp
     src/fonts/pdf_fonts/encoding/tounicode_parser.cpp

engine/src/fonts/pdf_fonts/font_extraction_service.cpp

@@ -0,0 +1,49 @@
+#include "font_extraction_service.hpp"
+#include "font_validator.hpp"
+#include "../../qpdf/qpdf_font_extractor.hpp"
+#include <spdlog/spdlog.h>
+
+namespace pdfengine::fonts::pdf_fonts {
+
+std::expected<std::shared_ptr<EmbeddedFontProgram>, EngineError>
+FontExtractionService::getFontProgram(const std::string& internalFontId,
+                                      const std::string& baseFontName,
+                                      const std::vector<uint8_t>& documentBuffer,
+                                      const std::vector<uint8_t>& pdfiumRawBytes) {
+    
+    std::lock_guard<std::mutex> lock(cacheMutex_);
+    if (cache_.count(internalFontId)) {
+        return cache_[internalFontId];
+    }
+
+    // 1. Try PDFium Bytes (Standard fonts)
+    if (!pdfiumRawBytes.empty() && FontValidator::isValidSFNT(pdfiumRawBytes)) {
+        auto prog = std::make_shared<EmbeddedFontProgram>();
+        prog->fontName = baseFontName;
+        prog->bytes = pdfiumRawBytes;
+        prog->source = FontExtractionSource::PDFium;
+        
+        cache_[internalFontId] = prog;
+        spdlog::info("[FontExtraction] internalId='{}' source=PDFium size={}", internalFontId, prog->bytes.size());
+        return prog;
+    }
+
+    // 2. Try QPDF Fallback (Type0 CIDFonts)
+    if (!documentBuffer.empty()) {
+        qpdf_layer::QpdfFontExtractor qpdfExtractor;
+        auto qpdfProg = qpdfExtractor.extractFontProgram(documentBuffer, baseFontName);
+        if (qpdfProg && FontValidator::isValidSFNT(qpdfProg->bytes)) {
+            auto prog = std::make_shared<EmbeddedFontProgram>(*qpdfProg);
+            prog->source = FontExtractionSource::QPDF_Raw;
+            cache_[internalFontId] = prog;
+            spdlog::info("[FontExtraction] internalId='{}' source=QPDF_Raw size={}", internalFontId, prog->bytes.size());
+            return prog;
+        }
+    }
+
+    // Tier 2 Reconstruction would happen here if needed, but for now we return not found
+    spdlog::warn("[FontExtraction] Failed to extract valid SFNT for '{}'", internalFontId);
+    return std::unexpected(EngineError::FileNotFound);
+}
+
+} // namespace pdfengine::fonts::pdf_fonts

engine/src/fonts/pdf_fonts/font_extraction_service.hpp

@@ -0,0 +1,37 @@
+#pragma once
+
+#include <cstdint>
+#include <string>
+#include <vector>
+#include <unordered_map>
+#include <memory>
+#include <mutex>
+#include <optional>
+#include <expected>
+
+#include "font_extraction_types.hpp"
+#include <pdfengine/pdf_document.hpp>
+
+namespace pdfengine::fonts::pdf_fonts {
+
+class FontExtractionService {
+public:
+    static FontExtractionService& getInstance() {
+        static FontExtractionService instance;
+        return instance;
+    }
+
+    std::expected<std::shared_ptr<EmbeddedFontProgram>, EngineError>
+    getFontProgram(const std::string& internalFontId,
+                   const std::string& baseFontName,
+                   const std::vector<uint8_t>& documentBuffer,
+                   const std::vector<uint8_t>& pdfiumRawBytes);
+
+private:
+    FontExtractionService() = default;
+
+    std::mutex cacheMutex_;
+    std::unordered_map<std::string, std::shared_ptr<EmbeddedFontProgram>> cache_;
+};
+
+} // namespace pdfengine::fonts::pdf_fonts

engine/src/fonts/pdf_fonts/font_extraction_types.hpp

@@ -0,0 +1,20 @@
+#pragma once
+
+#include <cstdint>
+#include <string>
+#include <vector>
+
+namespace pdfengine::fonts::pdf_fonts {
+
+enum class FontProgramType { Unknown, TrueType, CFF, OpenType, Type1 };
+
+enum class FontExtractionSource { PDFium, QPDF_Raw, QPDF_Reconstructed, Cache };
+
+struct EmbeddedFontProgram {
+    std::string fontName;
+    std::vector<uint8_t> bytes;
+    FontProgramType type = FontProgramType::Unknown;
+    FontExtractionSource source = FontExtractionSource::PDFium;
+};
+
+} // namespace pdfengine::fonts::pdf_fonts

engine/src/fonts/pdf_fonts/font_validator.cpp

@@ -0,0 +1,28 @@
+#include "font_validator.hpp"
+
+namespace pdfengine::fonts::pdf_fonts {
+
+bool FontValidator::isValidSFNT(const std::vector<uint8_t>& bytes) {
+    if (bytes.size() < 12) { // Minimum SFNT header size
+        return false;
+    }
+
+    // Check SFNT version / magic bytes
+    // 0x00010000 for TrueType
+    // 0x4F54544F ("OTTO") for OpenType CFF
+    // 0x74727565 ("true") for Apple TrueType
+    // 0x74797031 ("typ1") for Mac PostScript Type 1
+    const uint8_t* b = bytes.data();
+    uint32_t magic = (static_cast<uint32_t>(b[0]) << 24) |
+                     (static_cast<uint32_t>(b[1]) << 16) |
+                     (static_cast<uint32_t>(b[2]) << 8) |
+                      static_cast<uint32_t>(b[3]);
+
+    if (magic == 0x00010000 || magic == 0x4F54544F || magic == 0x74727565 || magic == 0x74797031) {
+        return true;
+    }
+
+    return false;
+}
+
+} // namespace pdfengine::fonts::pdf_fonts

engine/src/fonts/pdf_fonts/font_validator.hpp

@@ -0,0 +1,13 @@
+#pragma once
+
+#include <cstdint>
+#include <vector>
+
+namespace pdfengine::fonts::pdf_fonts {
+
+class FontValidator {
+public:
+    static bool isValidSFNT(const std::vector<uint8_t>& bytes);
+};
+
+} // namespace pdfengine::fonts::pdf_fonts

engine/src/parser/pdfium_fonts.cpp

@@ -1,5 +1,5 @@
 #include "parser/pdfium_internal.hpp"
-
+#include "fonts/pdf_fonts/font_extraction_service.hpp"
 namespace pdfengine::parser {
 
 void PdfiumDocument::registerAuxFont(const std::string& internalFontId, const std::vector<uint8_t>& sfnt) {
@@ -607,6 +607,13 @@ std::expected<std::vector<uint8_t>, EngineError> PdfiumDocument::getFontData(con
     
     std::string expectedFontName = baseNameFromInternalFontId(internalFontId);
     
+    // 1. Try cache via service
+    auto cachedProg = fonts::pdf_fonts::FontExtractionService::getInstance().getFontProgram(
+        internalFontId, expectedFontName, memoryBuffer_, {});
+    if (cachedProg) {
+        return (*cachedProg)->bytes;
+    }
+    
     int numPages = FPDF_GetPageCount(doc_);
     
     int startPage = 0;
@@ -639,37 +646,31 @@ std::expected<std::vector<uint8_t>, EngineError> PdfiumDocument::getFontData(con
             
             FPDF_FONT font = FPDFTextObj_GetFont(obj);
             if (!font) continue;
-            
             size_t nameLen = FPDFFont_GetBaseFontName(font, nullptr, 0);
             if (nameLen > 0) {
                 std::vector<char> nameBuf(nameLen);
                 if (FPDFFont_GetBaseFontName(font, nameBuf.data(), nameLen) > 0) {
                     std::string fontName(nameBuf.data());
-                    
-                    std::lock_guard<std::mutex> lock(fontsMutex_);
-                    
-                    if (fontDataCache_.find(fontName) == fontDataCache_.end()) {
+                    if (fontName == expectedFontName) {
+                        std::vector<uint8_t> pdfiumBytes;
                         size_t buflen = 0;
                         FPDFFont_GetFontData(font, nullptr, 0, &buflen);
                         if (buflen > 0) {
-                            std::vector<uint8_t> buffer(buflen);
+                            pdfiumBytes.resize(buflen);
                             size_t actual_len = 0;
-                            if (FPDFFont_GetFontData(font, buffer.data(), buflen, &actual_len)) {
-                                fontDataCache_[fontName] = buffer;
-                            } else {
-                                fontDataCache_[fontName] = std::vector<uint8_t>();
-                            }
-                        } else {
-                            fontDataCache_[fontName] = std::vector<uint8_t>();
+                            FPDFFont_GetFontData(font, pdfiumBytes.data(), buflen, &actual_len);
                         }
-                    }
-                    
-                    if (fontName == expectedFontName) {
-                        const auto& cachedBuf = fontDataCache_[fontName];
-                        if (!cachedBuf.empty()) {
-                            FPDF_ClosePage(page);
-                            fontDataScannedPages_ = i;
-                            return cachedBuf;
+                        
+                        FPDF_ClosePage(page);
+                        fontDataScannedPages_ = i;
+                        
+                        auto prog = fonts::pdf_fonts::FontExtractionService::getInstance().getFontProgram(
+                            internalFontId, expectedFontName, memoryBuffer_, pdfiumBytes);
+                            
+                        if (prog) {
+                            return (*prog)->bytes;
+                        } else {
+                            return std::unexpected(prog.error());
                         }
                     }
                 }
@@ -681,12 +682,15 @@ std::expected<std::vector<uint8_t>, EngineError> PdfiumDocument::getFontData(con
         fontDataScannedPages_ = i + 1;
     }
     
-    {
-        std::lock_guard<std::mutex> lock(fontsMutex_);
-        if (fontDataCache_.find(expectedFontName) == fontDataCache_.end()) {
-            fontDataCache_[expectedFontName] = std::vector<uint8_t>();
-        }
+    // If we searched all pages and didn't find the expected font name in FPDF objects,
+    // let the FontExtractionService try QPDF fallback on the whole document as a last resort.
+    auto finalProg = fonts::pdf_fonts::FontExtractionService::getInstance().getFontProgram(
+        internalFontId, expectedFontName, memoryBuffer_, {});
+        
+    if (finalProg) {
+        return (*finalProg)->bytes;
     }
+    
     return std::unexpected(EngineError::FileNotFound);
 #else
     (void)internalFontId;

engine/src/qpdf/qpdf_font_extractor.cpp

@@ -11,6 +11,7 @@
 #endif
 
 #include <cstdio>
+#include <spdlog/spdlog.h>
 
 namespace pdfengine::qpdf_layer {
 
@@ -46,6 +47,7 @@ QpdfFontExtractor::extractMapping(const std::vector<uint8_t>& pdf, const std::st
         ::QPDF qpdf;
         qpdf.processMemoryFile("memory", reinterpret_cast<const char*>(pdf.data()), pdf.size());
 
+        std::optional<QPDFObjectHandle> bestObj;
         for (QPDFObjectHandle obj : qpdf.getAllObjects()) {
             if (!obj.isDictionary()) continue;
             if (!obj.hasKey("/Type") || !obj.getKey("/Type").isName() ||
@@ -53,43 +55,60 @@ QpdfFontExtractor::extractMapping(const std::vector<uint8_t>& pdf, const std::st
                 continue;
             if (!baseFontMatches(obj, baseFontName)) continue;
 
-            EmbeddedFontMapping m;
-            m.subtype = obj.hasKey("/Subtype") && obj.getKey("/Subtype").isName()
-                            ? obj.getKey("/Subtype").getName() : "";
-
-            if (obj.hasKey("/ToUnicode") && obj.getKey("/ToUnicode").isStream()) {
-                std::string s = decodeStream(obj.getKey("/ToUnicode"));
-                if (!s.empty() && fonts::pdf_fonts::ToUnicodeParser::parse(s, m.codeToUnicode))
-                    m.hasToUnicode = !m.codeToUnicode.empty();
+            bestObj = obj;
+            if (obj.hasKey("/ToUnicode")) {
+                break; // Found the parent Type0 font!
             }
+        }
 
-            if (m.subtype == "/Type0" && obj.hasKey("/DescendantFonts")) {
-                QPDFObjectHandle df = obj.getKey("/DescendantFonts");
-                QPDFObjectHandle cid = df.isArray() && df.getArrayNItems() > 0 ? df.getArrayItem(0)
-                                                                              : QPDFObjectHandle();
-                if (cid.isDictionary() && cid.hasKey("/CIDToGIDMap")) {
-                    QPDFObjectHandle c2g = cid.getKey("/CIDToGIDMap");
-                    if (c2g.isStream()) {
-                        std::string s = decodeStream(c2g);
-                        m.identityCidToGid = false;
-                        for (size_t i = 0; i + 1 < s.size(); i += 2) {
-                            uint16_t gid = static_cast<uint16_t>((static_cast<uint8_t>(s[i]) << 8) |
-                                                                 static_cast<uint8_t>(s[i + 1]));
-                            if (gid != 0) m.codeToGid[static_cast<uint32_t>(i / 2)] = gid;
-                        }
-                    } else {
-                        m.identityCidToGid = true;  
+        if (!bestObj) return std::unexpected(QpdfError::Unknown);
+        QPDFObjectHandle obj = *bestObj;
+
+        spdlog::info("[DEBUG] Found best matching font dictionary for {}", baseFontName);
+
+        EmbeddedFontMapping m;
+        m.subtype = obj.hasKey("/Subtype") && obj.getKey("/Subtype").isName()
+                        ? obj.getKey("/Subtype").getName() : "";
+
+        if (obj.hasKey("/ToUnicode") && obj.getKey("/ToUnicode").isStream()) {
+            std::string s = decodeStream(obj.getKey("/ToUnicode"));
+            if (s.empty()) {
+                spdlog::info("[DEBUG] ToUnicode stream is empty after decodeStream!");
+            } else {
+                bool parseOk = fonts::pdf_fonts::ToUnicodeParser::parse(s, m.codeToUnicode);
+                if (!parseOk) {
+                    spdlog::info("[DEBUG] ToUnicodeParser::parse returned false!");
+                }
+                m.hasToUnicode = !m.codeToUnicode.empty();
+            }
+        }
+
+        if (m.subtype == "/Type0" && obj.hasKey("/DescendantFonts")) {
+            QPDFObjectHandle df = obj.getKey("/DescendantFonts");
+            QPDFObjectHandle cid = df.isArray() && df.getArrayNItems() > 0 ? df.getArrayItem(0)
+                                                                          : QPDFObjectHandle();
+            if (cid.isDictionary() && cid.hasKey("/CIDToGIDMap")) {
+                QPDFObjectHandle c2g = cid.getKey("/CIDToGIDMap");
+                if (c2g.isStream()) {
+                    std::string s = decodeStream(c2g);
+                    m.identityCidToGid = false;
+                    for (size_t i = 0; i + 1 < s.size(); i += 2) {
+                        uint16_t gid = static_cast<uint16_t>((static_cast<uint8_t>(s[i]) << 8) |
+                                                             static_cast<uint8_t>(s[i + 1]));
+                        if (gid != 0) m.codeToGid[static_cast<uint32_t>(i / 2)] = gid;
                     }
                 } else {
-                    m.identityCidToGid = true;
+                    m.identityCidToGid = true;  
                 }
             } else {
                 m.identityCidToGid = true;
             }
-
-            m.ok = m.hasToUnicode;
-            return m;
+        } else {
+            m.identityCidToGid = true;
         }
+
+        m.ok = m.hasToUnicode;
+        return m;
         return std::unexpected(QpdfError::Unknown);  
     } catch (const QPDFExc& e) {
         fprintf(stderr, "QpdfFontExtractor QPDFExc: %s\n", e.what());
@@ -103,5 +122,72 @@ QpdfFontExtractor::extractMapping(const std::vector<uint8_t>& pdf, const std::st
     return std::unexpected(QpdfError::NotSupported);
 #endif
 }
+std::optional<fonts::pdf_fonts::EmbeddedFontProgram>
+QpdfFontExtractor::extractFontProgram(const std::vector<uint8_t>& pdf, const std::string& baseFontName) const {
+#ifdef PDFENGINE_WITH_QPDF
+    try {
+        ::QPDF qpdf;
+        qpdf.processMemoryFile("memory", reinterpret_cast<const char*>(pdf.data()), pdf.size());
+
+        for (QPDFObjectHandle obj : qpdf.getAllObjects()) {
+            if (!obj.isDictionary()) continue;
+            if (!obj.hasKey("/Type") || !obj.getKey("/Type").isName() ||
+                obj.getKey("/Type").getName() != "/Font")
+                continue;
+            if (!baseFontMatches(obj, baseFontName)) continue;
+
+            std::string subtype = obj.hasKey("/Subtype") && obj.getKey("/Subtype").isName()
+                                      ? obj.getKey("/Subtype").getName() : "";
+            
+            QPDFObjectHandle fontDesc;
+
+            if (subtype == "/Type0" && obj.hasKey("/DescendantFonts")) {
+                QPDFObjectHandle df = obj.getKey("/DescendantFonts");
+                if (df.isArray() && df.getArrayNItems() > 0) {
+                    QPDFObjectHandle cid = df.getArrayItem(0);
+                    if (cid.isDictionary() && cid.hasKey("/FontDescriptor")) {
+                        fontDesc = cid.getKey("/FontDescriptor");
+                    }
+                }
+            } else if (obj.hasKey("/FontDescriptor")) {
+                fontDesc = obj.getKey("/FontDescriptor");
+            }
+
+            if (!fontDesc.isDictionary()) continue;
+
+            QPDFObjectHandle streamObj;
+            fonts::pdf_fonts::FontProgramType ftype = fonts::pdf_fonts::FontProgramType::Unknown;
+
+            if (fontDesc.hasKey("/FontFile2") && fontDesc.getKey("/FontFile2").isStream()) {
+                streamObj = fontDesc.getKey("/FontFile2");
+                ftype = fonts::pdf_fonts::FontProgramType::TrueType;
+            } else if (fontDesc.hasKey("/FontFile3") && fontDesc.getKey("/FontFile3").isStream()) {
+                streamObj = fontDesc.getKey("/FontFile3");
+                ftype = fonts::pdf_fonts::FontProgramType::CFF;
+            } else if (fontDesc.hasKey("/FontFile") && fontDesc.getKey("/FontFile").isStream()) {
+                streamObj = fontDesc.getKey("/FontFile");
+                ftype = fonts::pdf_fonts::FontProgramType::Type1;
+            }
+
+            if (streamObj.isStream()) {
+                std::string s = decodeStream(streamObj);
+                if (!s.empty()) {
+                    fonts::pdf_fonts::EmbeddedFontProgram fp;
+                    fp.fontName = baseFontName;
+                    fp.bytes = std::vector<uint8_t>(s.begin(), s.end());
+                    fp.type = ftype;
+                    fp.source = fonts::pdf_fonts::FontExtractionSource::QPDF_Raw;
+                    return fp;
+                }
+            }
+        }
+    } catch (const std::exception& e) {
+        fprintf(stderr, "QpdfFontExtractor extractFontProgram exception: %s\n", e.what());
+    }
+#else
+    (void)pdf; (void)baseFontName;
+#endif
+    return std::nullopt;
+}
 
 } 

engine/src/qpdf/qpdf_font_extractor.hpp

@@ -7,6 +7,8 @@
 #include <vector>
 
 #include "qpdf_extractor.hpp" 
+#include <optional>
+#include "fonts/pdf_fonts/font_extraction_types.hpp"
 
 namespace pdfengine::qpdf_layer {
 
@@ -23,6 +25,9 @@ class QpdfFontExtractor {
 public:
     std::expected<EmbeddedFontMapping, QpdfError>
     extractMapping(const std::vector<uint8_t>& pdf, const std::string& baseFontName) const;
+
+    std::optional<fonts::pdf_fonts::EmbeddedFontProgram>
+    extractFontProgram(const std::vector<uint8_t>& pdf, const std::string& baseFontName) const;
 };
 
 }  

engine/tests/CMakeLists.txt

@@ -19,6 +19,7 @@ add_executable(pdfengine_smoke
     ast_serializer_test.cpp
     content_serializer_test.cpp
     qpdf_writer_test.cpp
+    font_extraction_test.cpp
 )
 
 if(PDFENGINE_WITH_QPDF)

engine/tests/font_extraction_test.cpp

@@ -0,0 +1,32 @@
+#include <gtest/gtest.h>
+#include "../src/fonts/pdf_fonts/font_extraction_service.hpp"
+#include "../src/fonts/pdf_fonts/font_validator.hpp"
+
+using namespace pdfengine::fonts::pdf_fonts;
+
+TEST(FontValidatorTest, ValidatesSFNT) {
+    // TrueType Magic: 0x00010000
+    std::vector<uint8_t> ttf = {0x00, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
+    EXPECT_TRUE(FontValidator::isValidSFNT(ttf));
+
+    // OTTO Magic
+    std::vector<uint8_t> otto = {'O', 'T', 'T', 'O', 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
+    EXPECT_TRUE(FontValidator::isValidSFNT(otto));
+
+    // Invalid Magic
+    std::vector<uint8_t> invalid = {0x12, 0x34, 0x56, 0x78, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
+    EXPECT_FALSE(FontValidator::isValidSFNT(invalid));
+
+    // Too small
+    std::vector<uint8_t> small = {0x00, 0x01, 0x00, 0x00};
+    EXPECT_FALSE(FontValidator::isValidSFNT(small));
+}
+
+TEST(FontExtractionServiceTest, FallbacksToQPDFIfPdfiumFails) {
+    auto& service = FontExtractionService::getInstance();
+    
+    // We expect it to return FileNotFound because we provided empty buffers
+    // but this ensures the code compiles and the service instance is accessible.
+    auto res = service.getFontProgram("F1", "TestFont", {}, {});
+    EXPECT_FALSE(res.has_value());
+}

frontend/index.html

@@ -5,6 +5,9 @@
     <link rel="icon" type="image/svg+xml" href="/favicon.svg" />
     <meta name="viewport" content="width=device-width, initial-scale=1.0" />
     <title>PDF Editor</title>
+    <link rel="preconnect" href="https://fonts.googleapis.com">
+    <link rel="preconnect" href="https://fonts.gstatic.com" crossorigin>
+    <link href="https://fonts.googleapis.com/css2?family=Arimo:wght@400;500;600;700&family=Inter:wght@400;500;600;700&display=swap" rel="stylesheet">
   </head>
   <body class="h-full w-full overflow-hidden bg-[#f1f2f4] text-[#18212e] antialiased">
     <div id="root" class="flex h-full w-full flex-col"></div>

frontend/src/lib/fontFaceLoader.ts

@@ -30,7 +30,10 @@ export function loadPdfFont(
   if (existing) return existing;
 
   const p = (async (): Promise<string | null> => {
-    const bytes = await gatewayService.getFontData(documentId, internalFontId);
+    let bytes = await gatewayService.getReconstructedFontData(documentId, internalFontId);
+    if (!bytes || bytes.byteLength === 0) {
+      bytes = await gatewayService.getFontData(documentId, internalFontId);
+    }
     if (!bytes || bytes.byteLength === 0) return null;
     const hint = (cssFamilyHint || '').replace(/^[A-Z]{6}\+/, '').trim();
     const family = hint

frontend/src/viewer/ParagraphEditor.tsx

@@ -74,7 +74,7 @@ function median(xs: number[]): number {
 function paraEffSize(lines: any[]): number {
   let nominal = 0;
   for (const line of lines) for (const r of (line.runs ?? [])) {
-    const sz = Math.max(r.font_size ?? 0, r.h ?? 0);
+    const sz = r.font_size && r.font_size > 0 ? r.font_size : (r.h ?? 0) * 0.8;
     if (sz > nominal) nominal = sz;
   }
   return nominal || 12;
@@ -105,7 +105,7 @@ function computeLayout(para: any): ParagraphLayout {
       }
       const adv = perRun[ri];
       const safeColor = sanitizeTextColor(r.color);
-      const rSize = Math.max(r.font_size ?? 0, r.h ?? 0) || effSize;
+      const rSize = (r.font_size && r.font_size > 0 ? r.font_size : (r.h ?? 0) * 0.8) || effSize;
       seedRuns.push({ text, fid: r.internal_font_id ?? '', size: rSize, color: safeColor, fontName: r.font_name ?? '', advances: adv });
       if (orig) lineFrags.push({ text: orig, fid: r.internal_font_id ?? '', size: rSize, color: safeColor, advances: adv });
     }
@@ -631,9 +631,26 @@ export const ParagraphEditor: React.FC<ParagraphEditorProps> = ({
   const colWidthPx = (columnRight - columnLeft) * zoom;
 
   // Fix 1: use extracted PDF font name (loaded via @font-face), not a generic Arial/Times/Courier map.
-  const extractedFamily = (domFontName || '').replace(/^[A-Z]{6}\+/, '').trim() || 'sans-serif';
-  const fallbackFamily = /times|serif/i.test(extractedFamily) ? 'Times New Roman, serif'
-    : /courier|mono/i.test(extractedFamily) ? 'Courier New, monospace' : 'Arial, sans-serif';
+  let extractedFamily = (domFontName || '').replace(/^[A-Z]{6}\+/, '').trim() || 'sans-serif';
+  // FIX: DO NOT split on hyphens here. If the font was downloaded via @font-face (e.g. "Arial-BoldMT"), 
+  // we must use the exact string "Arial-BoldMT" so the browser maps to the downloaded font, not the OS font.
+  
+  // FIX: Chrome on Windows forcefully aliases exactly "Helvetica" to "Arial" at the OS layer. 
+  // We bypass this hardcoded alias only if the original name is EXACTLY Helvetica or Arial.
+  const rawFamily = extractedFamily.toLowerCase();
+  if (rawFamily === 'helvetica' || rawFamily === 'arial') {
+    extractedFamily = `"Inter", ${extractedFamily}`;
+  }
+  
+  let fallbackFamily = '"Arimo", Arial, sans-serif';
+  if (/times|serif/i.test(extractedFamily)) {
+    fallbackFamily = 'Times New Roman, serif';
+  } else if (/courier|mono/i.test(extractedFamily)) {
+    fallbackFamily = 'Courier New, monospace';
+  } else {
+    fallbackFamily = '"Inter", "Arimo", Arial, sans-serif';
+  }
+  
   const [measureFamily, setMeasureFamily] = useState(
     extractedFamily !== 'sans-serif' ? `'${extractedFamily}', ${fallbackFamily}` : fallbackFamily,
   );
@@ -1011,7 +1028,7 @@ export const ParagraphEditor: React.FC<ParagraphEditorProps> = ({
       for (const ln of lines) {
         for (const r of (ln.runs ?? [])) {
           pdfFontName = r.font_name || pdfFontName;
-          pdfFontSize = Math.max(pdfFontSize, r.font_size ?? 0, r.h ?? 0);
+          pdfFontSize = Math.max(pdfFontSize, r.font_size && r.font_size > 0 ? r.font_size : (r.h ?? 0) * 0.8);
           for (const g of (r.glyphs ?? [])) {
             const x0 = g.bbox_x, y0 = g.bbox_y, x1 = g.bbox_x + g.bbox_w, y1 = g.bbox_y + g.bbox_h;
             pdfMinX = Math.min(pdfMinX, x0); pdfMinY = Math.min(pdfMinY, y0);

frontend/src/viewer/TextEditLayer.tsx

@@ -233,13 +233,29 @@ interface TextEditLayerProps {
 
 function fallbackFamily(fontName: string): string {
   const n = (fontName || '').toLowerCase();
+  
+  let baseFallback = '"Arimo", Arial, "Helvetica Neue", Helvetica, sans-serif';
   if (n.includes('times') || (n.includes('serif') && !n.includes('sans'))) {
-    return '"Times New Roman", Times, Georgia, serif';
+    baseFallback = '"Times New Roman", Times, Georgia, serif';
+  } else if (n.includes('courier') || n.includes('mono')) {
+    baseFallback = '"Courier New", Courier, monospace';
+  } else {
+    baseFallback = '"Inter", "Arimo", Arial, "Helvetica Neue", Helvetica, sans-serif';
   }
-  if (n.includes('courier') || n.includes('mono')) {
-    return '"Courier New", Courier, monospace';
+  
+  let cleanName = (fontName || '').replace(/^[A-Z]{6}\+/, '').trim();
+  
+  // FIX: Chrome on Windows forcefully aliases exactly "Helvetica" to "Arial" at the OS layer.
+  // By explicitly returning Inter here, we bypass this hardcoded alias so it renders the modern font instead of Arial.
+  const rawName = cleanName.toLowerCase();
+  if (rawName === 'helvetica' || rawName === 'arial') {
+    return `"Inter", ${baseFallback}`;
   }
-  return 'Arial, "Helvetica Neue", Helvetica, sans-serif';
+  
+  if (cleanName && !['arial', 'helvetica', 'times', 'courier', 'arimo', 'inter'].includes(rawName)) {
+    return `"${cleanName}", ${baseFallback}`;
+  }
+  return baseFallback;
 }
 
 function flattenRuns(model: any): EditableRun[] {
@@ -259,7 +275,7 @@ function flattenRuns(model: any): EditableRun[] {
             text: r.text,
             x: r.x, y: r.y, w: r.w, h: r.h,
             baselineY,
-            fontSize: Math.max(r.font_size ?? 0, r.h ?? 0),
+            fontSize: r.font_size && r.font_size > 0 ? r.font_size : (r.h ?? 0) * 0.8,
             objectIndices,
             internalFontId: r.internal_font_id ?? '',
             fontName: r.font_name ?? '',
@@ -281,7 +297,8 @@ function median(xs: number[]): number {
 }
 
 function displayFontSize(r: EditableRun): number {
-  return Math.max(r.fontSize ?? 0, r.h ?? 0);
+  if (r.fontSize && r.fontSize > 0) return r.fontSize;
+  return (r.h ?? 0) * 0.8;
 }
 
 function buildReflowPayload(model: any, run: EditableRun, newText: string): ReflowParagraphPayload | null {