Add color-hdr-1.vim

https://www.w3.org/TR/2024/WD-css-color-hdr-1-20241217/

after/syntax/css/color-hdr-1.vim

@@ -0,0 +1,3 @@
+syn keyword cssFontProp contained dynamic-range-limit
+syn keyword cssFontAttr contained standard constrained-high
+syn region cssFunction contained matchgroup=cssFunctionName start="\<dynamic-range-limit-mix\s*(" end=")" oneline keepend

test/test.css

@@ -176,6 +176,13 @@
   display: exact;
 }
 
+.color-hdr-1 {
+  dynamic-range-limit: auto;
+  display: standard;
+  display: constrained-high;
+  display: dynamic-range-limit-mix(standard 10%, constrained-high 40%, high 50%);
+}
+
 .compositing-1 {
   mix-blend-mode: auto;
   isolation: auto;