Add position-4.vim

https://www.w3.org/TR/2025/WD-css-position-4-20250708/

after/syntax/css/gaps-1.vim

@@ -0,0 +1,2 @@
+syn keyword cssFontProp contained column-rule-break row-rule-break rule-break column-rule-outset row-rule-outset rule-outset rule-paint-order row-rule-color row-rule-style row-rule-width row-rule rule-color rule-style rule-width rule
+syn keyword cssFontAttr contained spanning-item intersection row-over-column column-over-row

after/syntax/css/mixins-1.vim

@@ -0,0 +1,2 @@
+syn keyword cssFontProp contained result
+syn match cssFontDescriptor "@function\>" nextgroup=cssFontDescriptorBlock skipwhite skipnl

after/syntax/css/position-4.vim

@@ -0,0 +1,2 @@
+syn keyword cssFontProp contained overlay
+syn keyword cssPseudoClassId contained backdrop

after/syntax/css/pseudo-4.vim

@@ -1 +1 @@
-syn keyword cssPseudoClassId contained prefix postfix target-text spelling-error grammer-error file-selectors-button
+syn keyword cssPseudoClassId contained prefix suffix target-text spelling-error grammer-error file-selectors-button search-text details-content

after/syntax/css/shapes-1.vim

@@ -1,3 +1,3 @@
 syn keyword cssFontProp contained shape-outside shape-image-threshold shape-margin
 syn keyword cssFontAttr contained margin-box
-syn region cssFunction contained matchgroup=cssFunctionName start="\<\(inset\|circle\|ellipse\|polygon\)\s*(" end=")" oneline keepend
+syn region cssFunction contained matchgroup=cssFunctionName start="\<\(inset\|circle\|ellipse\|polygon\|shape\)\s*(" end=")" oneline keepend

test/test.css

@@ -517,13 +517,35 @@
 .forms-1:low-value,
 .forms-1:high-value,
 .forms-1:optimal-value {
-	slider-orientation: auto;
+  slider-orientation: auto;
-	display: base;
+  display: base;
-	display: control-value(<number>);
+  display: control-value(<number>);
-	display: left-to-right;
+  display: left-to-right;
-	display: right-to-left;
+  display: right-to-left;
-	display: top-to-bottom;
+  display: top-to-bottom;
-	display: bottom-to-top;
+  display: bottom-to-top;
+}
+
+.gaps-1 {
+  column-rule-break: auto;
+  row-rule-break: auto;
+  rule-break: auto;
+  column-rule-outset: auto;
+  row-rule-outset: auto;
+  rule-outset: auto;
+  rule-paint-order: auto;
+  row-rule-color: auto;
+  row-rule-style: auto;
+  row-rule-width: auto;
+  row-rule: auto;
+  rule-color: auto;
+  rule-style: auto;
+  rule-width: auto;
+  rule: auto;
+  display: spanning-item;
+  display: intersection;
+  display: row-over-column;
+  display: column-over-row;
 }
 
 .gcpm-3::footnote-call,
@@ -741,6 +763,10 @@ mask {
   mask-type: auto;
 }
 
+@function mixins-1() {
+  result: auto;
+}
+
 .motion-1 {
   offset-path: auto;
   offset-distance: auto;
@@ -853,6 +879,10 @@ mask {
   inset: auto;
 }
 
+.position-4::backdrop {
+  overlay: auto;
+}
+
 .properties-values-api-1 {
   syntax: auto;
   inherits: auto;
@@ -860,11 +890,13 @@ mask {
 }
 
 .pseudo-4::first-letter::prefix,
-.pseudo-4::first-letter::postfix,
+.pseudo-4::first-letter::suffix,
 .pseudo-4::target-text,
 .pseudo-4::spelling-error,
 .pseudo-4::grammer-error,
-.pseudo-4::file-selectors-button {
+.pseudo-4::file-selectors-button,
+.pseudo-4::search-text,
+.pseudo-4::details-content {
   display: auto;
 }
 
@@ -1073,10 +1105,11 @@ mask {
   display: circle(100px 50px 100px);
   display: ellipse(0 0 250px 100px);
   display: polygon(0 0, 100% 100%, 0 100%);
+  display: shape(from 0% 0%, hline to 100%, line to 0% 100%, vline to 0%);
 }
 
 .sizing-3 {
-  display: auto;
+display: auto;
 }
 
 .sizing-4 {