diff --git a/after/syntax/css/forms-1.vim b/after/syntax/css/forms-1.vim
new file mode 100644
index 0000000..31ce433
--- /dev/null
+++ b/after/syntax/css/forms-1.vim
@@ -0,0 +1,5 @@
+syn keyword cssFontProp contained slider-orientation
+syn keyword cssFontAttr contained base left-to-right right-to-left top-to-bottom bottom-to-top
+syn keyword cssPseudoClassId contained picker-icon file-selector-button checkmark thumb track fill field-text clear-icon placeholder step-control step-up step-down field-component field-separator color-swatch low-value high-value optimal-value
+syn region cssPseudoClassFn contained matchgroup=cssFunctionName start="\<picker(" end=")" contains=cssStringQ,cssStringQQ
+syn region cssFunction contained matchgroup=cssFunctionName start="\<control-value\s*(" end=")" oneline keepend
diff --git a/test/test.css b/test/test.css
index 1d53244..5ddddb9 100644
--- a/test/test.css
+++ b/test/test.css
@@ -497,6 +497,35 @@
   override-color: 1 rgb(43, 12, 9);
 }
 
+.forms-1::picker(select),
+.forms-1::picker-icon,
+.forms-1::file-selector-button,
+.forms-1::checkmark,
+.forms-1::thumb,
+.forms-1::track,
+.forms-1::fill
+.forms-1::field-text,
+.forms-1::clear-icon,
+.forms-1::placeholder,
+.forms-1::field-text,
+.forms-1::step-control,
+.forms-1::step-up,
+.forms-1::step-down,
+.forms-1::field-component,
+.forms-1::field-separator,
+.forms-1::color-swatch,
+.forms-1:low-value,
+.forms-1:high-value,
+.forms-1:optimal-value {
+	slider-orientation: auto;
+	display: base;
+	display: control-value(<number>);
+	display: left-to-right;
+	display: right-to-left;
+	display: top-to-bottom;
+	display: bottom-to-top;
+}
+
 .gcpm-3::footnote-call,
 .gcpm-3::footnote-marker {
   running: auto;