Sourced from tailwindcss's releases.

v4.1.18

Fixed

• Ensure validation of source(…) happens relative to the file it is in (#19274)
• Include filename and line numbers in CSS parse errors (#19282)
• Skip comments in Ruby files when checking for class names (#19243)
• Skip over arbitrary property utilities with a top-level ! in the value (#19243)
• Support environment API in @tailwindcss/vite (#18970)
• Preserve case of theme keys from JS configs and plugins (#19337)
• Write source maps correctly on the CLI when using --watch (#19373)
• Handle special defaults (like ringColor.DEFAULT) in JS configs (#19348)
• Improve backwards compatibility for content theme key from JS configs (#19381)
• Upgrade: Handle future and experimental config keys (#19344)
• Try to canonicalize any arbitrary utility to a bare value (#19379)
• Validate candidates similarly to Oxide (#19397)
• Canonicalization: combine text-* and leading-* classes (#19396)
• Correctly handle duplicate CLI arguments (#19416)
• Don’t emit color-mix fallback rules inside @keyframes (#19419)
• CLI: Don't hang when output is /dev/stdout (#19421)

Sourced from tailwindcss's changelog.

[4.1.18] - 2025-12-11

Fixed

• Ensure validation of source(…) happens relative to the file it is in (#19274)
• Include filename and line numbers in CSS parse errors (#19282)
• Skip comments in Ruby files when checking for class names (#19243)
• Skip over arbitrary property utilities with a top-level ! in the value (#19243)
• Support environment API in @tailwindcss/vite (#18970)
• Preserve case of theme keys from JS configs and plugins (#19337)
• Write source maps correctly on the CLI when using --watch (#19373)
• Handle special defaults (like ringColor.DEFAULT) in JS configs (#19348)
• Improve backwards compatibility for content theme key from JS configs (#19381)
• Upgrade: Handle future and experimental config keys (#19344)
• Try to canonicalize any arbitrary utility to a bare value (#19379)
• Validate candidates similarly to Oxide (#19397)
• Canonicalization: combine text-* and leading-* classes (#19396)
• Correctly handle duplicate CLI arguments (#19416)
• Don’t emit color-mix fallback rules inside @keyframes (#19419)
• CLI: Don't hang when output is /dev/stdout (#19421)

[3.4.19] - 2025-12-10

Fixed

• Don’t break sibling-*() functions when used inside calc(…) (#19335)

• 9b32f7c Release v4.1.18 (#19431)
• 820d907 Expose candidatesToAst to the language server (#19405)
• 478e959 Don’t emit color-mix fallback rules inside @keyframes (#19419)
• a5f4644 Validate named values in candidate parser (#19397)
• 229121d Canonicalization: combine text-* and leading-* classes (#19396)
• 243615e Handle backwards compatibility for content theme from JS configs (#19381)
• 7642751 Improve compatibility with special default values in JS configs (#19348)
• af48117 remove unnecessary intermediate check
• 9e436f7 Try to canonicalize any arbitrary utility to a bare value (#19379)
• 479b725 Bump Vitest to v4 (#19216)
• Additional commits viewable in compare view

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