Center images via display block and margin auto not working with RenderMode.sliverList

[DFelten]

Steps to Reproduce

It's possible to center an image via style="display: block; margin: 0 auto;". This is working for RenderMode.column. But as soon as I changed the render mode to sliverList, the image is no longer centered.

HTML

<img style="display: block; margin: 0 auto;" src="https://www.monsterdealz.de/app/uploads/2025/11/IMG_0025-276x600.jpg"
    alt="" width="276" height="600" />

<p>Lorem ipsum dolor sit amet consectetur adipisicing elit. Repellat necessitatibus quod ratione earum praesentium
    consequuntur tempora alias nulla recusandae accusamus aliquam atque doloremque nesciunt assumenda, autem ea laborum
    consectetur. Numquam!</p>

`HtmlWidget` configuration (SliverList) -> Not working

import 'package:flutter/material.dart';
import 'package:flutter_widget_from_html/flutter_widget_from_html.dart';

const kHtml = '''
<img style="display: block; margin: 0 auto;" src="https://www.monsterdealz.de/app/uploads/2025/11/IMG_0025-276x600.jpg"
    alt="" width="276" height="600" />

<p>Lorem ipsum dolor sit amet consectetur adipisicing elit. Repellat necessitatibus quod ratione earum praesentium
    consequuntur tempora alias nulla recusandae accusamus aliquam atque doloremque nesciunt assumenda, autem ea laborum
    consectetur. Numquam!</p>
''';

class CustomWidgetBuilderScreen extends StatelessWidget {
  const CustomWidgetBuilderScreen({super.key});

  @override
  Widget build(BuildContext context) => Scaffold(
    appBar: AppBar(
      title: const Text('CustomWidgetBuilderScreen'),
    ),
    body: const CustomScrollView(
      slivers: [
        HtmlWidget(
          kHtml,
          renderMode: RenderMode.sliverList,
        ),
      ],
    ),
  );
}

`HtmlWidget` configuration (Column) -> Working

import 'package:flutter/material.dart';
import 'package:flutter_widget_from_html/flutter_widget_from_html.dart';

const kHtml = '''
<img style="display: block; margin: 0 auto;" src="https://www.monsterdealz.de/app/uploads/2025/11/IMG_0025-276x600.jpg"
    alt="" width="276" height="600" />

<p>Lorem ipsum dolor sit amet consectetur adipisicing elit. Repellat necessitatibus quod ratione earum praesentium
    consequuntur tempora alias nulla recusandae accusamus aliquam atque doloremque nesciunt assumenda, autem ea laborum
    consectetur. Numquam!</p>
''';

class CustomWidgetBuilderScreen extends StatelessWidget {
  const CustomWidgetBuilderScreen({super.key});

  @override
  Widget build(BuildContext context) => Scaffold(
    appBar: AppBar(
      title: const Text('CustomWidgetBuilderScreen'),
    ),
    body: const SingleChildScrollView(
      child: Padding(
        padding: EdgeInsets.all(8.0),
        child: HtmlWidget(
          kHtml,
        ),
      ),
    ),
  );
}

Tesing environment

[✓] Flutter (Channel stable, 3.35.7, on macOS 26.1 25B78 darwin-arm64, locale de-DE) [1.553ms]
    • Flutter version 3.35.7 on channel stable at /Users/danielfelten/fvm/versions/3.35.7
    • Upstream repository https://github.com/flutter/flutter.git
    • Framework revision adc9010625 (5 weeks ago), 2025-10-21 14:16:03 -0400
    • Engine revision 035316565a
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[!] Android toolchain - develop for Android devices (Android SDK version 35.0.0) [4,9s]
    • Android SDK at /Users/danielfelten/Library/Android/sdk
    • Emulator version 36.1.9.0 (build_id 13823996) (CL:N/A)
    • Platform android-36, build-tools 35.0.0
    • Java binary at: /Users/danielfelten/.sdkman/candidates/java/current/bin/java
      This JDK is specified in your Flutter configuration.
      To change the current JDK, run: `flutter config --jdk-dir="path/to/jdk"`.
    • Java version OpenJDK Runtime Environment JBR-17.0.12+1-1087.25-jcef (build 17.0.12+1-b1087.25)
    ! Some Android licenses not accepted. To resolve this, run: flutter doctor --android-licenses

[✓] Xcode - develop for iOS and macOS (Xcode 26.1.1) [3,9s]
    • Xcode at /Applications/Xcode.app/Contents/Developer
    • Build 17B100
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[✓] Chrome - develop for the web [144ms]
    • Chrome at /Applications/Google Chrome.app/Contents/MacOS/Google Chrome

[✓] Android Studio (version 2025.1) [144ms]
    • Android Studio at /Users/danielfelten/Applications/Android Studio.app/Contents
    • Flutter plugin can be installed from:
      🔨 https://plugins.jetbrains.com/plugin/9212-flutter
    • Dart plugin can be installed from:
      🔨 https://plugins.jetbrains.com/plugin/6351-dart
    • Java version OpenJDK Runtime Environment (build 21.0.6+-13391695-b895.109)

[✓] IntelliJ IDEA Ultimate Edition (version 2025.1.3) [142ms]
    • IntelliJ at /Users/danielfelten/Applications/IntelliJ IDEA Ultimate.app
    • Flutter plugin version 87.1
    • Dart plugin version 251.27623.5

[✓] VS Code (version 1.105.1) [19ms]
    • VS Code at /Applications/Visual Studio Code.app/Contents
    • Flutter extension version 3.120.0

[✓] VS Code (version 1.107.0-insider) [19ms]
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    • Flutter extension version 3.123.20251030

[✓] Connected device (4 available) [7,1s]
    • iPhone 16 Pro von Daniel (wireless) (mobile) • 00008140-000C71910253001C            • ios            • iOS 26.2 23C5044b
    • iPhone 17 Pro (mobile)                       • C8B00EE3-5817-4C45-85E2-79288D340473 • ios            • com.apple.CoreSimulator.SimRuntime.iOS-26-1 (simulator)
    • macOS (desktop)                              • macos                                • darwin-arm64   • macOS 26.1 25B78 darwin-arm64
    • Chrome (web)                                 • chrome                               • web-javascript • Google Chrome 142.0.7444.176

[✓] Network resources [259ms]
    • All expected network resources are available.

! Doctor found issues in 1 category.

Expected results

Actual results