Update dependency io.sf.carte:css4j to v6.1

[renovate-bot]

This PR contains the following updates:

Package	Change	Age	Adoption	Passing	Confidence
io.sf.carte:css4j (source)	6.0 -> 6.1

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Release Notes

css4j/css4j (io.sf.carte:css4j)

v6.1

Compare Source

June 26, 2025

Highlights

Upgraded generic CSS minifier

The Minify
class was upgraded to be more appropriate for generic minification tasks, and
the serialization is now shorter. For example, the following style rule:

div {
 /* Verbose longhand properties */
  color: rgba(255,255,0,255);
  background-color: rgb(from lime r calc(g - 127) b);

 /* Shorthands with inefficient values */
  border-radius: initial; /* Some compressors would remove this but that's wrong */
  margin: 2px 2px 2px 2px;
  background: url('bkg.png') left top round space padding-box border-box local;
}

is minified as

div{color:#ff0;background-color:green;border-radius:0;margin:2px;background:url(bkg.png) round space local}

Minify can be used like a normal class, or via the command line with the alldeps jar:

java -jar path/to/css4j-6.1-alldeps.jar verbose.css --charset ISO-8859-1 > minified.css

Note that UTF-8 is the default character set. The alldeps fat jar is now
part of the standard css4j distribution.

The command-line minifier exits with a status code of 0 if it ran successfully,
2 if the arguments were incorrect, and 1 if a parsing error was found in the
style sheet and a simpler minifier was used.

More information is available at the minification section of the usage guide.
Css4j is now used to minify the CSS in the css4j website.

Relative color syntax

Relative color syntax from Color Level 5 is supported.

background: oklch(from var(--base) l c calc(h + 180));

Relevant specification: https://www.w3.org/TR/css-color-5/#relative-colors

Parse and serialize the if function

The if function was shipped by Chrome 137. The argument contains both colons
and semicolons, which prevented the parsing with previous versions of the
library:

background-color: if (style(--color: white): black; else: white);

The library can now do a basic parsing of the function but cannot provide the
intended final value at the computed style level.

Relevant specification: https://drafts.csswg.org/css-values-5/#if-notation

Selectors: allow multiple conditions in Combinator (AND) conditions

This only affects you in the unlikely case that you work with selectors at low
level. The old API was a bottleneck in the processing of conditional selectors.

Detail of changes

• NSAC: allow multiple conditions in Combinator (AND) conditions.
• NSAC/CSSOM: relative colors.
• NSAC/CSSOM: parse the if function.
• Add a parser flags constructor to CSSOMParser.
• CSSOM: matching of of-type pseudo-classes was case sensitive.
• CSSOM: allow var() values in media query features.
• CSSOM: add equals() and hashCode() to AbstractStyleSheet.
• CSSOM: make the deprecated CSSStyleSheet.createSupportsRule() a default method.
• util: improve the generic CSS minifier.
• Remove unnecessary argument in grouping rule check.
• Upgrade to TokenProducer 3.3.
• Upgrade to checkstyle 10.26.0.
• Upgrade JUnit to 5.13.2.
• Upgrade Gradle wrapper to 8.14.2.

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