diff --git a/src/css/selectors/parser.rs b/src/css/selectors/parser.rs
index ac6dd4d8edfb..9404d01ccbc8 100644
--- a/src/css/selectors/parser.rs
+++ b/src/css/selectors/parser.rs
@@ -1222,7 +1222,7 @@ impl<'a> SelectorParser<'a> {
         // `::View-Transition-Group(..)` fall through to `CustomFunction`,
         // so look up `name` verbatim with no case folding.
         //
-        // PERF: 6 entries with near-unique lengths (3/10/19/19/21/26) —
+        // PERF: 7 entries with near-unique lengths (3/6/10/19/19/21/26) —
         // a length-gated `match` rejects the overwhelmingly-common miss path
         // (unknown `::-webkit-foo(...)` etc.) on a single `usize` compare,
         // versus a hash lookup's hash + table load + slice compare. Only
@@ -1236,6 +1236,11 @@ impl<'a> SelectorParser<'a> {
                     selector: Box::new(Selector::parse(self, input)?),
                 });
             }
+            6 if name == b"picker" => {
+                return Ok(PseudoElement::PickerFunction {
+                    identifier: Ident::parse(input)?,
+                });
+            }
             10 if name == b"cue-region" => {
                 return Ok(PseudoElement::CueRegionFunction {
                     selector: Box::new(Selector::parse(self, input)?),
@@ -1552,6 +1557,9 @@ fn lookup_pseudo_element(name: &[u8]) -> Option<PseudoElement> {
         b"-webkit-scrollbar-corner" => PE::WebkitScrollbar(WS::Corner),
         b"-webkit-resizer" => PE::WebkitScrollbar(WS::Resizer),
         b"view-transition" => PE::ViewTransition,
+        b"details-content" => PE::DetailsContent,
+        b"picker-icon" => PE::PickerIcon,
+        b"checkmark" => PE::Checkmark,
         _ => return None,
     } })
 }
@@ -2959,6 +2967,17 @@ pub enum PseudoElement {
         /// A part name selector.
         part_name: ViewTransitionPartName,
     },
+    /// The [::details-content](https://drafts.csswg.org/css-pseudo-4/#details-content-pseudo) pseudo element.
+    DetailsContent,
+    /// The [::picker-icon](https://drafts.csswg.org/css-forms-1/#picker-icon-pseudo) pseudo element.
+    PickerIcon,
+    /// The [::checkmark](https://drafts.csswg.org/css-forms-1/#checkmark-pseudo) pseudo element.
+    Checkmark,
+    /// The [::picker()](https://drafts.csswg.org/css-forms-1/#picker-pseudo) functional pseudo element.
+    PickerFunction {
+        /// The identifier argument, e.g. `select` in `::picker(select)`.
+        identifier: Ident,
+    },
     /// An unknown pseudo element.
     Custom {
         /// The name of the pseudo element.
@@ -3088,6 +3107,10 @@ impl fmt::Display for PseudoElement {
             Self::ViewTransitionImagePair { .. } => "view_transition_image_pair",
             Self::ViewTransitionOld { .. } => "view_transition_old",
             Self::ViewTransitionNew { .. } => "view_transition_new",
+            Self::DetailsContent => "details_content",
+            Self::PickerIcon => "picker_icon",
+            Self::Checkmark => "checkmark",
+            Self::PickerFunction { .. } => "picker_function",
             Self::Custom { .. } => "custom",
             Self::CustomFunction { .. } => "custom_function",
         })
diff --git a/src/css/selectors/selector.rs b/src/css/selectors/selector.rs
index 2b6728268c4c..3109fdd519d9 100644
--- a/src/css/selectors/selector.rs
+++ b/src/css/selectors/selector.rs
@@ -1255,6 +1255,14 @@ pub(crate) mod serialize {
                 part_name.to_css(dest)?;
                 dest.write_char(b')')?;
             }
+            PseudoElement::DetailsContent => dest.write_str(b"::details-content")?,
+            PseudoElement::PickerIcon => dest.write_str(b"::picker-icon")?,
+            PseudoElement::Checkmark => dest.write_str(b"::checkmark")?,
+            PseudoElement::PickerFunction { identifier } => {
+                dest.write_str(b"::picker(")?;
+                identifier.to_css(dest)?;
+                dest.write_char(b')')?;
+            }
             PseudoElement::Custom { name } => {
                 dest.write_str(b"::")?;
                 return dest.serialize_identifier(name);
diff --git a/test/bundler/css/forms-pseudo-elements-41120.test.ts b/test/bundler/css/forms-pseudo-elements-41120.test.ts
new file mode 100644
index 000000000000..bdd33443ae57
--- /dev/null
+++ b/test/bundler/css/forms-pseudo-elements-41120.test.ts
@@ -0,0 +1,48 @@
+import { describe, expect, test } from "bun:test";
+import { tempDir } from "harness";
+import path from "node:path";
+
+// https://github.com/oven-sh/bun/issues/41120
+// ::details-content, ::picker(), ::checkmark and ::picker-icon are known
+// pseudo-elements (css-pseudo-4 and css-forms-1, also in lightningcss's
+// tables). Bundling them must not emit an "Unsupported pseudo-class or
+// pseudo-element" warning.
+describe("css", () => {
+  test("known form pseudo-elements do not warn (#41120)", async () => {
+    using dir = tempDir("css-41120", {
+      "in.css": `
+        .a::details-content { height: auto }
+        .b::picker(select) { border: none }
+        .c::checkmark { color: teal }
+        .d::picker-icon { rotate: 90deg }
+      `,
+    });
+    const result = await Bun.build({
+      entrypoints: [path.join(String(dir), "in.css")],
+      minify: true,
+      throw: true,
+    });
+    expect(result.logs.map(String)).toEqual([]);
+    const out = await result.outputs[0].text();
+    expect(out.trim()).toBe(
+      ".a::details-content{height:auto}.b::picker(select){border:none}.c::checkmark{color:teal}.d::picker-icon{rotate:90deg}",
+    );
+  });
+
+  test("the pseudo-element lookup is case-insensitive (#41120)", async () => {
+    using dir = tempDir("css-41120-case", {
+      "in.css": `
+        .a::DETAILS-CONTENT { height: auto }
+        .b::Checkmark { color: teal }
+      `,
+    });
+    const result = await Bun.build({
+      entrypoints: [path.join(String(dir), "in.css")],
+      minify: true,
+      throw: true,
+    });
+    expect(result.logs.map(String)).toEqual([]);
+    const out = await result.outputs[0].text();
+    expect(out.trim()).toBe(".a::details-content{height:auto}.b::checkmark{color:teal}");
+  });
+});