This project applies custom CSS themes to both the Maven-generated documentation site and the JaCoCo coverage reports so they share a consistent visual identity: light backgrounds, GitHub-inspired colors, purple gradient accents, and rounded card-style containers.

src/site/
├── resources/
│   ├── css/
│   │   └── site.css                  ← Maven site theme (loaded automatically by Fluido)
│   └── images/
│       └── github-copilot.jpg        ← Copilot logo for "Powered By" sidebar
├── jacoco-resources/
│   └── report.css                    ← JaCoCo report theme (overlaid after generation)
└── site.xml                          ← Fluido skin configuration

.github/
├── templates/
│   ├── index.html                    ← Version picker page template
│   └── styles.css                    ← Version picker CSS
└── workflows/
    └── deploy-site.yml               ← Deploys site + overlays JaCoCo CSS

The Maven Fluido Skin 2.1.0 (configured in src/site/site.xml) automatically loads css/site.css from the site resources directory. No additional configuration is needed — placing the file at src/site/resources/css/site.css is sufficient.

The Fluido skin renders a "Fork me on GitHub" ribbon using a ::after pseudo-element with content: attr(data-ribbon). We override this to say "View on GitHub" with a purple gradient background:

.github-fork-ribbon:before {
  background-color: #667eea !important;
  background-image: linear-gradient(135deg, #667eea, #764ba2) !important;
}

.github-fork-ribbon:after {
  content: 'View on GitHub' !important;
}

Note: Both background-color and background-image with !important are required because Fluido injects an inline <style> tag that sets the ribbon background.

The poweredBy section in Fluido's sidebar doesn't support custom entries via site.xml (the <poweredBy> element isn't supported in Maven Site Descriptor 2.0.0). Instead, the logo is injected via a CSS ::after pseudo-element on the #poweredBy div:

#poweredBy::after {
  content: '';
  display: block;
  width: 240px;
  height: 120px;
  background-image: url('../images/github-copilot.jpg');
  background-size: contain;
  background-repeat: no-repeat;
  background-position: center;
}

The logo image is stored at src/site/resources/images/github-copilot.jpg.

JaCoCo generates standalone HTML reports with their own report.css, completely independent of the Maven site theme. The generated reports reference jacoco-resources/report.css via a <link> tag. There is no built-in mechanism to customize this CSS.

The custom CSS is applied by replacing JaCoCo's default report.css after report generation. This happens through two mechanisms:

In pom.xml, a maven-resources-plugin execution runs during the site phase — after JaCoCo has generated its report and default CSS:

<execution>
    <id>overlay-jacoco-css</id>
    <phase>site</phase>
    <goals>
        <goal>copy-resources</goal>
    </goals>
    <configuration>
        <outputDirectory>${project.reporting.outputDirectory}/jacoco/jacoco-resources</outputDirectory>
        <resources>
            <resource>
                <directory>src/site/jacoco-resources</directory>
                <filtering>false</filtering>
            </resource>
        </resources>
        <overwrite>true</overwrite>
    </configuration>
</execution>

The deploy workflow (deploy-site.yml) has a catch-all step that overlays the CSS across all version directories in the site. This covers cases where the Maven overlay ran in a different directory structure:

- name: Overlay custom JaCoCo CSS
  run: |
    cd site
    for dir in */jacoco/jacoco-resources; do
      if [ -d "$dir" ]; then
        cp ../src/site/jacoco-resources/report.css "$dir/report.css"
        echo "Overlaid JaCoCo CSS in $dir"
      fi
    done

The JaCoCo reporting plugin (used during mvn site) outputs to jacoco/ by default. The build plugin execution (build-coverage-report-from-tests, phase verify) outputs to jacoco-coverage/. Only the reporting plugin path matters for the deployed site, since the deploy workflow runs mvn site, not mvn verify.

The JaCoCo theme mirrors the main site design:

JaCoCo only generates a report when test execution data (.exec file) exists:

• Snapshot builds in CI: The deploy workflow downloads test results from the "Build & Test" workflow and restores the .exec file before running mvn site. Reports are generated.
• Release tag builds: Tests don't run at tag checkout, so no .exec file exists and JaCoCo skips report generation. No report to style.
• Local builds: Run mvn clean verify site to ensure tests run first and the .exec file is available for report generation.

The index.html and styles.css in .github/templates/ power the top-level version picker at the documentation root. These are not part of the Maven site — they are copied directly by the deploy workflow.

The styles use the same design language (purple gradients, rounded cards, GitHub-blue links) but are a standalone CSS file with no dependency on Bootstrap or Fluido.

Edit src/site/resources/css/site.css. Changes take effect on the next mvn site build. Preview locally:

mvn clean site -DskipTests -Dcheckstyle.skip=true
open target/site/index.html

Edit src/site/jacoco-resources/report.css. Preview locally (requires test data):

mvn clean verify site
open target/site/jacoco/index.html

Edit .github/templates/index.html and .github/templates/styles.css. These are deployed as-is by the workflow — no build step needed. Preview by opening index.html directly in a browser.