V8.4.0

Features

• Support for PHP 8.x
• PHPDoc annotations
• Allow usage of CSS variables inside color functions (by parsing them as regular functions)
• Use PSR-12 code style
• No deprecations

Bugfixes

• Improved handling of whitespace in calc()
• Fix parsing units whose prefix is also a valid unit, like vmin
• Allow passing an object to CSSList#replace
• Fix PHP 7.3 warnings
• Correctly parse keyframes with %
• Don’t convert large numbers to scientific notation
• Allow a file to end after an @import
• Preserve case of CSS variables as specced
• Allow identifiers to use escapes the same way as strings
• No longer use eval for the comparison in getSelectorsBySpecificity, in case it gets passed untrusted input (CVE-2020-13756). Also fixed in 8.3.1, 8.2.1, 8.1.1, 8.0.1, 7.0.4, 6.0.2, 5.2.1, 5.1.3, 5.0.9, 4.0.1, 3.0.1, 2.0.1, 1.0.1.
• Prevent an infinite loop when parsing invalid grid line names
• Remove invalid unit vm
• Retain rule order after expanding shorthands

Backwards-incompatible changes

• PHP ≥ 5.6 is now required
• HHVM compatibility target dropped