diff --git a/server-ce/nginx/clsi-nginx.conf b/server-ce/nginx/clsi-nginx.conf
index 5ce22a3f56..b907ecfcce 100644
--- a/server-ce/nginx/clsi-nginx.conf
+++ b/server-ce/nginx/clsi-nginx.conf
@@ -25,8 +25,19 @@ server {
   gzip_types text/plain;
   gzip_proxied any;
   types {
-      text/plain log blg aux stdout stderr;
-      application/pdf pdf;
+      text/html                  html htm;
+      text/css                   css;
+      application/javascript     js;
+      application/json           json;
+      image/svg+xml              svg svgz;
+      image/png                  png;
+      image/jpeg                 jpeg jpg;
+      image/gif                  gif;
+      image/webp                 webp;
+      font/woff                  woff;
+      font/woff2                 woff2;
+      application/pdf            pdf;
+      text/plain                 log blg aux stdout stderr txt;
   }
   # handle output files for specific users
   location ~ ^/project/([0-9a-f]+)/user/([0-9a-f]+)/build/([0-9a-f-]+)/output/(.+)$ {
diff --git a/services/clsi/app/js/CompileController.js b/services/clsi/app/js/CompileController.js
index 53925c1291..9545d900a2 100644
--- a/services/clsi/app/js/CompileController.js
+++ b/services/clsi/app/js/CompileController.js
@@ -90,7 +90,10 @@ function compile(req, res, next) {
             } else {
               if (
                 outputFiles.some(
-                  file => file.path === 'output.pdf' && file.size > 0
+                  file =>
+                    (file.path === 'output.pdf' ||
+                      file.path === 'output.html') &&
+                    file.size > 0
                 )
               ) {
                 status = 'success'
diff --git a/services/clsi/app/js/QuartoRunner.js b/services/clsi/app/js/QuartoRunner.js
index c548861b20..f54048f0cd 100644
--- a/services/clsi/app/js/QuartoRunner.js
+++ b/services/clsi/app/js/QuartoRunner.js
@@ -50,11 +50,21 @@ function runQuarto(compileName, options, callback) {
 
 function _buildQuartoCommand(mainFile) {
   // Run through a POSIX shell so stderr is merged into stdout (2>&1).
-  // Quarto writes all progress and error messages to stderr; without this
-  // the log panel would be empty on failure.
   // LocalCommandRunner replaces $COMPILE_DIR before the shell sees it.
+  //
+  // We do NOT pass --to or --output: let the YAML frontmatter decide the
+  // output format (typst → output.pdf, revealjs → output.html, etc.).
+  // --embed-resources makes HTML output self-contained (ignored for typst).
+  // After render we rename the produced file to the canonical output name
+  // expected by the rest of the pipeline.
   const inputPath = `$COMPILE_DIR/${mainFile}`
-  const cmd = `quarto render ${inputPath} --to typst --output output.pdf 2>&1`
+  const baseName = mainFile.replace(/\.[^/.]+$/, '') // strip extension
+  const pdfOut = `$COMPILE_DIR/${baseName}.pdf`
+  const htmlOut = `$COMPILE_DIR/${baseName}.html`
+  const cmd =
+    `quarto render ${inputPath} --embed-resources 2>&1 && ` +
+    `(mv ${pdfOut} $COMPILE_DIR/output.pdf 2>/dev/null || ` +
+    `mv ${htmlOut} $COMPILE_DIR/output.html 2>/dev/null)`
   return ['/bin/sh', '-c', cmd]
 }
 
diff --git a/services/web/frontend/js/features/pdf-preview/components/pdf-viewer.tsx b/services/web/frontend/js/features/pdf-preview/components/pdf-viewer.tsx
index c4d79243b4..657ad95cbb 100644
--- a/services/web/frontend/js/features/pdf-preview/components/pdf-viewer.tsx
+++ b/services/web/frontend/js/features/pdf-preview/components/pdf-viewer.tsx
@@ -12,6 +12,19 @@ function PdfViewer() {
     return null
   }
 
+  // HTML outputs (RevealJS, etc.) must always use the native iframe;
+  // PDF.js cannot render HTML.
+  if (pdfUrl.includes('output.html')) {
+    return (
+      <iframe
+        title="Presentation Preview"
+        src={pdfUrl}
+        style={{ width: '100%', height: '100%', border: 'none' }}
+        sandbox="allow-scripts allow-same-origin allow-presentation allow-popups"
+      />
+    )
+  }
+
   switch (pdfViewer) {
     case 'native':
       return <iframe title="PDF Preview" src={pdfUrl} />
diff --git a/services/web/frontend/js/features/pdf-preview/util/output-files.ts b/services/web/frontend/js/features/pdf-preview/util/output-files.ts
index f869311d29..ab27bd3188 100644
--- a/services/web/frontend/js/features/pdf-preview/util/output-files.ts
+++ b/services/web/frontend/js/features/pdf-preview/util/output-files.ts
@@ -24,7 +24,9 @@ export function handleOutputFiles(
   projectId: string,
   data: CompileResponseData
 ): PDFFile | null {
-  const outputFile = outputFiles.get('output.pdf')
+  // Accept either a PDF or an HTML output (e.g. RevealJS presentation)
+  const outputFile =
+    outputFiles.get('output.pdf') ?? outputFiles.get('output.html')
   if (!outputFile) return null
 
   outputFile.editorId = outputFile.editorId || EDITOR_SESSION_ID
@@ -54,7 +56,7 @@ export function handleOutputFiles(
     params.set('popupDownload', 'true') // save PDF download as file
     params.set('editorId', outputFile.editorId)
 
-    outputFile.pdfDownloadUrl = `/download/project/${projectId}/build/${outputFile.build}/output/output.pdf?${params}`
+    outputFile.pdfDownloadUrl = `/download/project/${projectId}/build/${outputFile.build}/output/${outputFile.path}?${params}`
   }
 
   return outputFile