diff --git a/Auto Run Docs/SpecKit-web-header-analyzer-Phase-06-Interactive-Report.md b/Auto Run Docs/SpecKit-web-header-analyzer-Phase-06-Interactive-Report.md
index f94ad25..d20c4ef 100644
--- a/Auto Run Docs/SpecKit-web-header-analyzer-Phase-06-Interactive-Report.md	
+++ b/Auto Run Docs/SpecKit-web-header-analyzer-Phase-06-Interactive-Report.md	
@@ -54,7 +54,7 @@ ReportContainer
 - [x] Security appliances show as badges; empty state handled gracefully
 - [x] Search filters results in real-time across test name, header name, and analysis text
 - [x] Export JSON produces a valid JSON file containing all results
-- [ ] Export HTML produces a styled standalone page viewable in any browser
+- [x] Export HTML produces a styled standalone page viewable in any browser
 - [ ] All report components are keyboard accessible
 - [ ] Linting passes (`npx eslint src/`, `npx prettier --check src/`)
 - [ ] Run `/speckit.analyze` to verify consistency
diff --git a/frontend/src/__tests__/report/ReportExport.test.tsx b/frontend/src/__tests__/report/ReportExport.test.tsx
index ee46b24..3e847d0 100644
--- a/frontend/src/__tests__/report/ReportExport.test.tsx
+++ b/frontend/src/__tests__/report/ReportExport.test.tsx
@@ -136,7 +136,7 @@ describe("ReportExport", () => {
     expect(createObjectUrlSpy).toHaveBeenCalled();
     expect(clickSpy).toHaveBeenCalled();
     expect(lastBlob).not.toBeNull();
-    expect(lastBlob?.type).toBe("application/json");
+    expect(lastBlob?.type).toBe("application/json;charset=utf-8");
 
     const text = await lastBlob?.text();
     const parsed = JSON.parse(text ?? "{}") as AnalysisReport;
@@ -144,7 +144,7 @@ describe("ReportExport", () => {
     expect(parsed.results[0]?.testId).toBe(101);
   });
 
-  it("triggers an HTML download", () => {
+  it("triggers an HTML download with styled markup", async () => {
     const { container } = render(<ReportExport report={report} />);
 
     const htmlButton = getByTestId(container, "report-export-html");
@@ -155,5 +155,13 @@ describe("ReportExport", () => {
 
     expect(createObjectUrlSpy).toHaveBeenCalled();
     expect(clickSpy).toHaveBeenCalled();
+    expect(lastBlob?.type).toBe("text/html;charset=utf-8");
+
+    const text = await lastBlob?.text();
+    expect(text).toContain("<!doctype html>");
+    expect(text).toContain("<style>");
+    expect(text).toContain("Email Header Analysis Report");
+    expect(text).toContain("Summary");
+    expect(text).toContain("SpamAssassin Rule Hits");
   });
 });
diff --git a/frontend/src/components/report/ReportExport.tsx b/frontend/src/components/report/ReportExport.tsx
index f8fe857..adda87e 100644
--- a/frontend/src/components/report/ReportExport.tsx
+++ b/frontend/src/components/report/ReportExport.tsx
@@ -147,6 +147,7 @@ const buildHtmlReport = (report: AnalysisReport): string => {
         background: var(--background);
         color: var(--text);
         font-family: "Geist", "Segoe UI", system-ui, sans-serif;
+        line-height: 1.5;
       }
 
       main {
@@ -162,6 +163,11 @@ const buildHtmlReport = (report: AnalysisReport): string => {
         margin: 0 0 4px;
       }
 
+      h2 {
+        font-size: 18px;
+        margin: 0 0 12px;
+      }
+
       .muted {
         color: var(--muted);
         font-size: 13px;
@@ -427,16 +433,20 @@ const downloadBlob = (content: string, mimeType: string, fileName: string) => {
   document.body.appendChild(anchor);
   anchor.click();
   anchor.remove();
-  URL.revokeObjectURL(url);
+  window.setTimeout(() => URL.revokeObjectURL(url), 1000);
 };
 
 export default function ReportExport({ report }: ReportExportProps) {
   const handleJsonExport = () => {
-    downloadBlob(JSON.stringify(report, null, 2), "application/json", "analysis-report.json");
+    downloadBlob(
+      JSON.stringify(report, null, 2),
+      "application/json;charset=utf-8",
+      "analysis-report.json",
+    );
   };
 
   const handleHtmlExport = () => {
-    downloadBlob(buildHtmlReport(report), "text/html", "analysis-report.html");
+    downloadBlob(buildHtmlReport(report), "text/html;charset=utf-8", "analysis-report.html");
   };
 
   return (
