From cb4c1ecd1973765dc5844958e3050740ea403982 Mon Sep 17 00:00:00 2001
From: Yuki Hattori <yukihattori1116@gmail.com>
Date: Sat, 21 Oct 2023 22:24:21 +0900
Subject: [PATCH 1/2] Enable PNG image transparency

---
 src/converter.ts | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/src/converter.ts b/src/converter.ts
index 32a90330..78d2bfeb 100644
--- a/src/converter.ts
+++ b/src/converter.ts
@@ -392,6 +392,13 @@ export class Converter {
       await render()
       await page.emulateMediaType('print')
 
+      if (opts.type === ConvertType.png) {
+        // Enable transparency
+        await page.addStyleTag({
+          content: ':root,body { background:transparent !important; }',
+        })
+      }
+
       const screenshot = async (pageNumber = 1) => {
         const clip = {
           x: 0,
@@ -406,7 +413,11 @@ export class Converter {
             type: 'jpeg',
           })
 
-        return await page.screenshot({ clip, type: 'png' })
+        return await page.screenshot({
+          clip,
+          omitBackground: true,
+          type: 'png',
+        })
       }
 
       if (opts.pages) {

From 3b8eb385a2018288ce463de9fc6bcd1084e14336 Mon Sep 17 00:00:00 2001
From: Yuki Hattori <yukihattori1116@gmail.com>
Date: Sat, 28 Oct 2023 19:10:59 +0900
Subject: [PATCH 2/2] [ci skip] Update CHANGELOG.md

---
 CHANGELOG.md | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index dfc41e01..641765ec 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -8,6 +8,10 @@
 - Upgrade Marp Core to [v3.9.0](https://github.com/marp-team/marp-core/releases/v3.9.0) ([#557](https://github.com/marp-team/marp-cli/pull/557))
 - Upgrade dependent packages to the latest versions ([#557](https://github.com/marp-team/marp-cli/pull/557))
 
+### Fixed
+
+- Enable PNG image transparency ([#555](https://github.com/marp-team/marp-cli/issues/555), [#556](https://github.com/marp-team/marp-cli/pull/556))
+
 ## v3.3.1 - 2023-10-01
 
 ### Fixed