Add items-baseline-last utility (#13888)

This PR adds the `items-first-baseline` and `items-last-baseline`
utility classes that can control
[`baseline-position`](https://developer.mozilla.org/en-US/docs/Web/CSS/align-items#formal_syntax)
for the [align-items
property](https://developer.mozilla.org/en-US/docs/Web/CSS/align-items#baseline).

Browser support:
- MDN:
https://developer.mozilla.org/en-US/docs/Web/CSS/align-items#browser_compatibility
- Can I use `first baseline`:
https://caniuse.com/?search=align%20items%3A%20first%20baseline
- Can I use `last baseline`:
https://caniuse.com/?search=align%20items%3A%20last%20baseline

The feature were requested multiple times:

- https://github.com/tailwindlabs/tailwindcss/discussions/13518
- https://github.com/tailwindlabs/tailwindcss/discussions/12406
- https://github.com/tailwindlabs/tailwindcss/discussions/11623
- https://github.com/tailwindlabs/tailwindcss/discussions/4855

---------

Co-authored-by: Philipp Spiess <hello@philippspiess.com>

CHANGELOG.md

@@ -12,6 +12,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - _Experimental_: Add `details-content` variant ([#15319](https://github.com/tailwindlabs/tailwindcss/pull/15319))
 - _Experimental_: Add `inverted-colors` variant ([#11693](https://github.com/tailwindlabs/tailwindcss/pull/11693))
 - _Experimental_: Add `scripting`, `scripting-none`, and `scripting-initial` variants ([#11929](https://github.com/tailwindlabs/tailwindcss/pull/11929))
+- _Experimental_: Add `items-baseline-last` utility ([#12128](https://github.com/tailwindlabs/tailwindcss/pull/12128))
 - _Experimental_: Add `pointer-none`, `pointer-coarse`, and `pointer-fine` variant ([#16946](https://github.com/tailwindlabs/tailwindcss/pull/16946))
 - _Experimental_: Add `any-pointer-none`, `any-pointer-coarse`, and `any-pointer-fine` variants ([#16941](https://github.com/tailwindlabs/tailwindcss/pull/16941))
 - _Experimental_: Add `user-valid` and `user-invalid` variants ([#12370](https://github.com/tailwindlabs/tailwindcss/pull/12370))

packages/tailwindcss/src/__snapshots__/intellisense.test.ts.snap

@@ -4875,6 +4875,7 @@ exports[`getClassList 1`] = `
   "isolation-auto",
   "italic",
   "items-baseline",
+  "items-baseline-last",
   "items-center",
   "items-end",
   "items-start",

packages/tailwindcss/src/feature-flags.ts

@@ -1,3 +1,4 @@
+export const enableBaselineLast = process.env.FEATURES_ENV !== 'stable'
 export const enableDetailsContent = process.env.FEATURES_ENV !== 'stable'
 export const enableInvertedColors = process.env.FEATURES_ENV !== 'stable'
 export const enablePointerVariants = process.env.FEATURES_ENV !== 'stable'

packages/tailwindcss/src/utilities.test.ts

@@ -7312,12 +7312,24 @@ test('align-content', async () => {
 })
 
 test('items', async () => {
-  expect(await run(['items-start', 'items-end', 'items-center', 'items-baseline', 'items-stretch']))
-    .toMatchInlineSnapshot(`
+  expect(
+    await run([
+      'items-start',
+      'items-end',
+      'items-center',
+      'items-baseline',
+      'items-baseline-last',
+      'items-stretch',
+    ]),
+  ).toMatchInlineSnapshot(`
     ".items-baseline {
       align-items: baseline;
     }
 
+    .items-baseline-last {
+      align-items: last baseline;
+    }
+
     .items-center {
       align-items: center;
     }
@@ -7341,6 +7353,8 @@ test('items', async () => {
       '-items-end',
       '-items-center',
       '-items-baseline',
+      '-items-first-baseline',
+      '-items-last-baseline',
       '-items-stretch',
       'items-start/foo',
       'items-end/foo',

packages/tailwindcss/src/utilities.ts

@@ -11,7 +11,7 @@ import {
 } from './ast'
 import type { Candidate, CandidateModifier, NamedUtilityValue } from './candidate'
 import type { DesignSystem } from './design-system'
-import { enableWrapAnywhere } from './feature-flags'
+import { enableBaselineLast, enableWrapAnywhere } from './feature-flags'
 import type { Theme, ThemeKey } from './theme'
 import { compareBreakpoints } from './utils/compare-breakpoints'
 import { DefaultMap } from './utils/default-map'
@@ -1882,6 +1882,9 @@ export function createUtilities(theme: Theme) {
   staticUtility('items-start', [['align-items', 'flex-start']])
   staticUtility('items-end', [['align-items', 'flex-end']])
   staticUtility('items-baseline', [['align-items', 'baseline']])
+  if (enableBaselineLast) {
+    staticUtility('items-baseline-last', [['align-items', 'last baseline']])
+  }
   staticUtility('items-stretch', [['align-items', 'stretch']])
 
   staticUtility('justify-normal', [['justify-content', 'normal']])