diff --git a/Cargo.lock b/Cargo.lock
index b8ac73f4f73..759830e6d06 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -4017,6 +4017,15 @@ dependencies = [
  "either",
 ]
 
+[[package]]
+name = "itertools"
+version = "0.14.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2b192c782037fadd9cfa75548310488aabdbf3d2da73885b31bd0abd03351285"
+dependencies = [
+ "either",
+]
+
 [[package]]
 name = "itoa"
 version = "1.0.15"
@@ -6457,8 +6466,8 @@ dependencies = [
 
 [[package]]
 name = "selectors"
-version = "0.27.0"
-source = "git+https://github.com/servo/stylo?branch=2025-03-15#03ffc85c45f53a3b11994f7c14adce7b90aa9c34"
+version = "0.28.0"
+source = "git+https://github.com/servo/stylo?branch=2025-05-01#7edd19e2f09570c6734161b4bb7d47859c8699bf"
 dependencies = [
  "bitflags 2.9.0",
  "cssparser",
@@ -6753,7 +6762,7 @@ dependencies = [
 [[package]]
 name = "servo_arc"
 version = "0.4.1"
-source = "git+https://github.com/servo/stylo?branch=2025-03-15#03ffc85c45f53a3b11994f7c14adce7b90aa9c34"
+source = "git+https://github.com/servo/stylo?branch=2025-05-01#7edd19e2f09570c6734161b4bb7d47859c8699bf"
 dependencies = [
  "serde",
  "stable_deref_trait",
@@ -7212,8 +7221,8 @@ dependencies = [
 
 [[package]]
 name = "stylo"
-version = "0.2.1"
-source = "git+https://github.com/servo/stylo?branch=2025-03-15#03ffc85c45f53a3b11994f7c14adce7b90aa9c34"
+version = "0.3.0"
+source = "git+https://github.com/servo/stylo?branch=2025-05-01#7edd19e2f09570c6734161b4bb7d47859c8699bf"
 dependencies = [
  "app_units",
  "arrayvec",
@@ -7227,7 +7236,7 @@ dependencies = [
  "fxhash",
  "icu_segmenter",
  "indexmap",
- "itertools 0.10.5",
+ "itertools 0.14.0",
  "itoa",
  "lazy_static",
  "log",
@@ -7270,8 +7279,8 @@ dependencies = [
 
 [[package]]
 name = "stylo_atoms"
-version = "0.2.0"
-source = "git+https://github.com/servo/stylo?branch=2025-03-15#03ffc85c45f53a3b11994f7c14adce7b90aa9c34"
+version = "0.3.0"
+source = "git+https://github.com/servo/stylo?branch=2025-05-01#7edd19e2f09570c6734161b4bb7d47859c8699bf"
 dependencies = [
  "string_cache",
  "string_cache_codegen",
@@ -7279,13 +7288,13 @@ dependencies = [
 
 [[package]]
 name = "stylo_config"
-version = "0.2.0"
-source = "git+https://github.com/servo/stylo?branch=2025-03-15#03ffc85c45f53a3b11994f7c14adce7b90aa9c34"
+version = "0.3.0"
+source = "git+https://github.com/servo/stylo?branch=2025-05-01#7edd19e2f09570c6734161b4bb7d47859c8699bf"
 
 [[package]]
 name = "stylo_derive"
-version = "0.2.0"
-source = "git+https://github.com/servo/stylo?branch=2025-03-15#03ffc85c45f53a3b11994f7c14adce7b90aa9c34"
+version = "0.3.0"
+source = "git+https://github.com/servo/stylo?branch=2025-05-01#7edd19e2f09570c6734161b4bb7d47859c8699bf"
 dependencies = [
  "darling",
  "proc-macro2",
@@ -7296,8 +7305,8 @@ dependencies = [
 
 [[package]]
 name = "stylo_dom"
-version = "0.2.0"
-source = "git+https://github.com/servo/stylo?branch=2025-03-15#03ffc85c45f53a3b11994f7c14adce7b90aa9c34"
+version = "0.3.0"
+source = "git+https://github.com/servo/stylo?branch=2025-05-01#7edd19e2f09570c6734161b4bb7d47859c8699bf"
 dependencies = [
  "bitflags 2.9.0",
  "stylo_malloc_size_of",
@@ -7305,8 +7314,8 @@ dependencies = [
 
 [[package]]
 name = "stylo_malloc_size_of"
-version = "0.2.0"
-source = "git+https://github.com/servo/stylo?branch=2025-03-15#03ffc85c45f53a3b11994f7c14adce7b90aa9c34"
+version = "0.3.0"
+source = "git+https://github.com/servo/stylo?branch=2025-05-01#7edd19e2f09570c6734161b4bb7d47859c8699bf"
 dependencies = [
  "app_units",
  "cssparser",
@@ -7322,13 +7331,13 @@ dependencies = [
 
 [[package]]
 name = "stylo_static_prefs"
-version = "0.2.0"
-source = "git+https://github.com/servo/stylo?branch=2025-03-15#03ffc85c45f53a3b11994f7c14adce7b90aa9c34"
+version = "0.3.0"
+source = "git+https://github.com/servo/stylo?branch=2025-05-01#7edd19e2f09570c6734161b4bb7d47859c8699bf"
 
 [[package]]
 name = "stylo_traits"
-version = "0.2.0"
-source = "git+https://github.com/servo/stylo?branch=2025-03-15#03ffc85c45f53a3b11994f7c14adce7b90aa9c34"
+version = "0.3.0"
+source = "git+https://github.com/servo/stylo?branch=2025-05-01#7edd19e2f09570c6734161b4bb7d47859c8699bf"
 dependencies = [
  "app_units",
  "bitflags 2.9.0",
@@ -7711,7 +7720,7 @@ dependencies = [
 [[package]]
 name = "to_shmem"
 version = "0.2.0"
-source = "git+https://github.com/servo/stylo?branch=2025-03-15#03ffc85c45f53a3b11994f7c14adce7b90aa9c34"
+source = "git+https://github.com/servo/stylo?branch=2025-05-01#7edd19e2f09570c6734161b4bb7d47859c8699bf"
 dependencies = [
  "cssparser",
  "servo_arc",
@@ -7724,7 +7733,7 @@ dependencies = [
 [[package]]
 name = "to_shmem_derive"
 version = "0.1.0"
-source = "git+https://github.com/servo/stylo?branch=2025-03-15#03ffc85c45f53a3b11994f7c14adce7b90aa9c34"
+source = "git+https://github.com/servo/stylo?branch=2025-05-01#7edd19e2f09570c6734161b4bb7d47859c8699bf"
 dependencies = [
  "darling",
  "proc-macro2",
diff --git a/Cargo.toml b/Cargo.toml
index b43c38b21b9..0ed813078f4 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -118,7 +118,7 @@ rustls-pemfile = "2.0"
 rustls-pki-types = "1.11"
 script_layout_interface = { path = "components/shared/script_layout" }
 script_traits = { path = "components/shared/script" }
-selectors = { git = "https://github.com/servo/stylo", branch = "2025-03-15" }
+selectors = { git = "https://github.com/servo/stylo", branch = "2025-05-01" }
 serde = "1.0.219"
 serde_bytes = "0.11"
 serde_json = "1.0"
@@ -126,7 +126,7 @@ servo-media = { git = "https://github.com/servo/media" }
 servo-media-dummy = { git = "https://github.com/servo/media" }
 servo-media-gstreamer = { git = "https://github.com/servo/media" }
 servo-tracing = { path = "components/servo_tracing" }
-servo_arc = { git = "https://github.com/servo/stylo", branch = "2025-03-15" }
+servo_arc = { git = "https://github.com/servo/stylo", branch = "2025-05-01" }
 smallbitvec = "2.6.0"
 smallvec = "1.15"
 snapshot = { path = "./components/shared/snapshot" }
@@ -135,12 +135,12 @@ string_cache = "0.8"
 string_cache_codegen = "0.5"
 strum = "0.26"
 strum_macros = "0.26"
-stylo = { git = "https://github.com/servo/stylo", branch = "2025-03-15" }
-stylo_atoms = { git = "https://github.com/servo/stylo", branch = "2025-03-15" }
-stylo_config = { git = "https://github.com/servo/stylo", branch = "2025-03-15" }
-stylo_dom = { git = "https://github.com/servo/stylo", branch = "2025-03-15" }
-stylo_malloc_size_of = { git = "https://github.com/servo/stylo", branch = "2025-03-15" }
-stylo_traits = { git = "https://github.com/servo/stylo", branch = "2025-03-15" }
+stylo = { git = "https://github.com/servo/stylo", branch = "2025-05-01" }
+stylo_atoms = { git = "https://github.com/servo/stylo", branch = "2025-05-01" }
+stylo_config = { git = "https://github.com/servo/stylo", branch = "2025-05-01" }
+stylo_dom = { git = "https://github.com/servo/stylo", branch = "2025-05-01" }
+stylo_malloc_size_of = { git = "https://github.com/servo/stylo", branch = "2025-05-01" }
+stylo_traits = { git = "https://github.com/servo/stylo", branch = "2025-05-01" }
 surfman = { git = "https://github.com/servo/surfman", rev = "f7688b4585f9e0b5d4bf8ee8e4a91e82349610b1", features = ["chains"] }
 syn = { version = "2", default-features = false, features = ["clone-impls", "derive", "parsing"] }
 synstructure = "0.13"
diff --git a/components/layout/flow/mod.rs b/components/layout/flow/mod.rs
index 772b150ae1c..0c326c4cc6d 100644
--- a/components/layout/flow/mod.rs
+++ b/components/layout/flow/mod.rs
@@ -2238,7 +2238,9 @@ fn block_size_is_zero_or_intrinsic(size: &StyleSize, containing_block: &Containi
             lp.is_definitely_zero() ||
                 (lp.0.has_percentage() && !containing_block.size.block.is_definite())
         },
-        StyleSize::AnchorSizeFunction(_) => unreachable!("anchor-size() should be disabled"),
+        StyleSize::AnchorSizeFunction(_) | StyleSize::AnchorContainingCalcFunction(_) => {
+            unreachable!("anchor-size() should be disabled")
+        },
     }
 }
 
diff --git a/components/layout/geom.rs b/components/layout/geom.rs
index 49f031cbd18..6a09519b7ed 100644
--- a/components/layout/geom.rs
+++ b/components/layout/geom.rs
@@ -767,7 +767,9 @@ impl From<StyleSize> for Size<LengthPercentage> {
             StyleSize::FitContent => Size::FitContent,
             StyleSize::FitContentFunction(lp) => Size::FitContentFunction(lp.0),
             StyleSize::Stretch => Size::Stretch,
-            StyleSize::AnchorSizeFunction(_) => unreachable!("anchor-size() should be disabled"),
+            StyleSize::AnchorSizeFunction(_) | StyleSize::AnchorContainingCalcFunction(_) => {
+                unreachable!("anchor-size() should be disabled")
+            },
         }
     }
 }
@@ -782,7 +784,9 @@ impl From<StyleMaxSize> for Size<LengthPercentage> {
             StyleMaxSize::FitContent => Size::FitContent,
             StyleMaxSize::FitContentFunction(lp) => Size::FitContentFunction(lp.0),
             StyleMaxSize::Stretch => Size::Stretch,
-            StyleMaxSize::AnchorSizeFunction(_) => unreachable!("anchor-size() should be disabled"),
+            StyleMaxSize::AnchorSizeFunction(_) | StyleMaxSize::AnchorContainingCalcFunction(_) => {
+                unreachable!("anchor-size() should be disabled")
+            },
         }
     }
 }
diff --git a/components/layout/layout_impl.rs b/components/layout/layout_impl.rs
index efd31057127..b8d91c38027 100644
--- a/components/layout/layout_impl.rs
+++ b/components/layout/layout_impl.rs
@@ -69,7 +69,7 @@ use style::traversal::DomTraversal;
 use style::traversal_flags::TraversalFlags;
 use style::values::computed::font::GenericFontFamily;
 use style::values::computed::{CSSPixelLength, FontSize, Length, NonNegativeLength};
-use style::values::specified::font::KeywordInfo;
+use style::values::specified::font::{KeywordInfo, QueryFontMetricsFlags};
 use style::{Zero, driver};
 use style_traits::{CSSPixel, SpeculativePainter};
 use stylo_atoms::Atom;
@@ -1100,8 +1100,7 @@ impl FontMetricsProvider for LayoutFontMetricsProvider {
         _vertical: bool,
         font: &Font,
         base_size: CSSPixelLength,
-        _in_media_query: bool,
-        _retrieve_math_scales: bool,
+        _flags: QueryFontMetricsFlags,
     ) -> FontMetrics {
         let font_context = &self.0;
         let font_group = self
diff --git a/components/layout/style_ext.rs b/components/layout/style_ext.rs
index 68a4481a2be..354da54d39b 100644
--- a/components/layout/style_ext.rs
+++ b/components/layout/style_ext.rs
@@ -375,6 +375,9 @@ impl ComputedValuesExt for ComputedValues {
                 Inset::Auto => LengthPercentageOrAuto::Auto,
                 Inset::AnchorFunction(_) => unreachable!("anchor() should be disabled"),
                 Inset::AnchorSizeFunction(_) => unreachable!("anchor-size() should be disabled"),
+                Inset::AnchorContainingCalcFunction(_) => {
+                    unreachable!("anchor() and anchor-size() should be disabled")
+                },
             }
         }
         let position = self.get_position();
@@ -495,7 +498,9 @@ impl ComputedValuesExt for ComputedValues {
             match inset {
                 Margin::LengthPercentage(v) => LengthPercentageOrAuto::LengthPercentage(v),
                 Margin::Auto => LengthPercentageOrAuto::Auto,
-                Margin::AnchorSizeFunction(_) => unreachable!("anchor-size() should be disabled"),
+                Margin::AnchorSizeFunction(_) | Margin::AnchorContainingCalcFunction(_) => {
+                    unreachable!("anchor-size() should be disabled")
+                },
             }
         }
         let margin = self.get_margin();
diff --git a/components/layout/taffy/stylo_taffy/convert.rs b/components/layout/taffy/stylo_taffy/convert.rs
index 03fbec292a4..5780be17c82 100644
--- a/components/layout/taffy/stylo_taffy/convert.rs
+++ b/components/layout/taffy/stylo_taffy/convert.rs
@@ -59,6 +59,7 @@ pub fn dimension(val: &stylo::Size) -> taffy::Dimension {
 
         // Anchor positioning will be flagged off for time being
         stylo::Size::AnchorSizeFunction(_) => unreachable!(),
+        stylo::Size::AnchorContainingCalcFunction(_) => unreachable!(),
     }
 }
 
@@ -77,6 +78,7 @@ pub fn max_size_dimension(val: &stylo::MaxSize) -> taffy::Dimension {
 
         // Anchor positioning will be flagged off for time being
         stylo::MaxSize::AnchorSizeFunction(_) => unreachable!(),
+        stylo::MaxSize::AnchorContainingCalcFunction(_) => unreachable!(),
     }
 }
 
@@ -88,6 +90,7 @@ pub fn margin(val: &stylo::MarginVal) -> taffy::LengthPercentageAuto {
 
         // Anchor positioning will be flagged off for time being
         stylo::MarginVal::AnchorSizeFunction(_) => unreachable!(),
+        stylo::MarginVal::AnchorContainingCalcFunction(_) => unreachable!(),
     }
 }
 
@@ -100,6 +103,7 @@ pub fn inset(val: &stylo::InsetVal) -> taffy::LengthPercentageAuto {
         // Anchor positioning will be flagged off for time being
         stylo::InsetVal::AnchorSizeFunction(_) => unreachable!(),
         stylo::InsetVal::AnchorFunction(_) => unreachable!(),
+        stylo::InsetVal::AnchorContainingCalcFunction(_) => unreachable!(),
     }
 }
 
diff --git a/tests/unit/style/custom_properties.rs b/tests/unit/style/custom_properties.rs
index 4556e930d02..b7c53535ea5 100644
--- a/tests/unit/style/custom_properties.rs
+++ b/tests/unit/style/custom_properties.rs
@@ -25,6 +25,7 @@ use style::stylesheets::layer_rule::LayerOrder;
 use style::stylist::Stylist;
 use style::values::computed::font::GenericFontFamily;
 use style::values::computed::{Context, Length};
+use style::values::specified::font::QueryFontMetricsFlags;
 use test::{self, Bencher};
 use url::Url;
 
@@ -37,8 +38,7 @@ impl FontMetricsProvider for DummyMetricsProvider {
         _vertical: bool,
         _font: &Font,
         _base_size: Length,
-        _in_media_query: bool,
-        _retrieve_math_scales: bool,
+        _flags: QueryFontMetricsFlags,
     ) -> FontMetrics {
         Default::default()
     }
diff --git a/tests/unit/style/stylist.rs b/tests/unit/style/stylist.rs
index 9fa422b2294..e5447968151 100644
--- a/tests/unit/style/stylist.rs
+++ b/tests/unit/style/stylist.rs
@@ -26,6 +26,7 @@ use style::stylist::{
 use style::thread_state::{self, ThreadState};
 use style::values::computed::Length;
 use style::values::computed::font::GenericFontFamily;
+use style::values::specified::font::QueryFontMetricsFlags;
 use stylo_atoms::Atom;
 use url::Url;
 
@@ -38,8 +39,7 @@ impl FontMetricsProvider for DummyMetricsProvider {
         _vertical: bool,
         _font: &Font,
         _base_size: Length,
-        _in_media_query: bool,
-        _retrieve_math_scales: bool,
+        _flags: QueryFontMetricsFlags,
     ) -> FontMetrics {
         Default::default()
     }