diff --git a/components/style/logical_geometry.rs b/components/style/logical_geometry.rs
index b6cc9ef5bc6..63aa5f138a4 100644
--- a/components/style/logical_geometry.rs
+++ b/components/style/logical_geometry.rs
@@ -171,6 +171,49 @@ impl WritingMode {
         }
     }
 
+    #[inline]
+    fn physical_sides_to_corner(block_side: PhysicalSide, inline_side: PhysicalSide) -> PhysicalCorner {
+        match (block_side, inline_side) {
+            (PhysicalSide::Top, PhysicalSide::Left) |
+            (PhysicalSide::Left, PhysicalSide::Top) => PhysicalCorner::TopLeft,
+            (PhysicalSide::Top, PhysicalSide::Right) |
+            (PhysicalSide::Right, PhysicalSide::Top) => PhysicalCorner::TopRight,
+            (PhysicalSide::Bottom, PhysicalSide::Right) |
+            (PhysicalSide::Right, PhysicalSide::Bottom) => PhysicalCorner::BottomRight,
+            (PhysicalSide::Bottom, PhysicalSide::Left) |
+            (PhysicalSide::Left, PhysicalSide::Bottom) => PhysicalCorner::BottomLeft,
+            _ => unreachable!("block and inline sides must be orthogonal")
+        }
+    }
+
+    #[inline]
+    pub fn start_start_physical_corner(&self) -> PhysicalCorner {
+        WritingMode::physical_sides_to_corner(
+            self.block_start_physical_side(),
+            self.inline_start_physical_side())
+    }
+
+    #[inline]
+    pub fn start_end_physical_corner(&self) -> PhysicalCorner {
+        WritingMode::physical_sides_to_corner(
+            self.block_start_physical_side(),
+            self.inline_end_physical_side())
+    }
+
+    #[inline]
+    pub fn end_start_physical_corner(&self) -> PhysicalCorner {
+        WritingMode::physical_sides_to_corner(
+            self.block_end_physical_side(),
+            self.inline_start_physical_side())
+    }
+
+    #[inline]
+    pub fn end_end_physical_corner(&self) -> PhysicalCorner {
+        WritingMode::physical_sides_to_corner(
+            self.block_end_physical_side(),
+            self.inline_end_physical_side())
+    }
+
     #[inline]
     pub fn block_flow_direction(&self) -> BlockFlowDirection {
         match (self.is_vertical(), self.is_vertical_lr()) {
@@ -1314,3 +1357,11 @@ pub enum PhysicalSide {
     Bottom,
     Left,
 }
+
+#[derive(Clone, Copy, Debug, PartialEq)]
+pub enum PhysicalCorner {
+    TopLeft,
+    TopRight,
+    BottomRight,
+    BottomLeft,
+}
diff --git a/components/style/properties/data.py b/components/style/properties/data.py
index fa4f55bc9e5..39b5743f4a9 100644
--- a/components/style/properties/data.py
+++ b/components/style/properties/data.py
@@ -8,10 +8,13 @@ PHYSICAL_SIDES = ["top", "right", "bottom", "left"]
 LOGICAL_SIDES = ["block-start", "block-end", "inline-start", "inline-end"]
 PHYSICAL_SIZES = ["width", "height"]
 LOGICAL_SIZES = ["block-size", "inline-size"]
+PHYSICAL_CORNERS = ["top-left", "top-right", "bottom-right", "bottom-left"]
+LOGICAL_CORNERS = ["start-start", "start-end", "end-start", "end-end"]
 
 # bool is True when logical
 ALL_SIDES = [(side, False) for side in PHYSICAL_SIDES] + [(side, True) for side in LOGICAL_SIDES]
 ALL_SIZES = [(size, False) for size in PHYSICAL_SIZES] + [(size, True) for size in LOGICAL_SIZES]
+ALL_CORNERS = [(corner, False) for corner in PHYSICAL_CORNERS] + [(corner, True) for corner in LOGICAL_CORNERS]
 
 SYSTEM_FONT_LONGHANDS = """font_family font_size font_style
                            font_variant_caps font_stretch font_kerning
@@ -239,12 +242,14 @@ class Longhand(object):
     def all_physical_mapped_properties(self):
         assert self.logical
         logical_side = None
-        for s in LOGICAL_SIDES + LOGICAL_SIZES:
+        for s in LOGICAL_SIDES + LOGICAL_SIZES + LOGICAL_CORNERS:
             if s in self.name:
                 assert not logical_side
                 logical_side = s
         assert logical_side
-        physical = PHYSICAL_SIDES if logical_side in LOGICAL_SIDES else PHYSICAL_SIZES
+        physical = PHYSICAL_SIDES if logical_side in LOGICAL_SIDES else \
+                   PHYSICAL_SIZES if logical_side in LOGICAL_SIZES else \
+                   LOGICAL_CORNERS
         return [self.name.replace(logical_side, physical_side).replace("inset-", "")
                 for physical_side in physical]
 
diff --git a/components/style/properties/helpers.mako.rs b/components/style/properties/helpers.mako.rs
index b37842ddc57..2139ff2be71 100644
--- a/components/style/properties/helpers.mako.rs
+++ b/components/style/properties/helpers.mako.rs
@@ -4,7 +4,7 @@
 
 <%!
     from data import Keyword, to_rust_ident, to_camel_case
-    from data import LOGICAL_SIDES, PHYSICAL_SIDES, LOGICAL_SIZES, SYSTEM_FONT_LONGHANDS
+    from data import LOGICAL_CORNERS, PHYSICAL_CORNERS, LOGICAL_SIDES, PHYSICAL_SIDES, LOGICAL_SIZES, SYSTEM_FONT_LONGHANDS
 %>
 
 <%def name="predefined_type(name, type, initial_value, parse_method='parse',
@@ -842,12 +842,16 @@
     <%
         side = None
         size = None
+        corner = None
         maybe_side = [s for s in LOGICAL_SIDES if s in name]
         maybe_size = [s for s in LOGICAL_SIZES if s in name]
+        maybe_corner = [s for s in LOGICAL_CORNERS if s in name]
         if len(maybe_side) == 1:
             side = maybe_side[0]
         elif len(maybe_size) == 1:
             size = maybe_size[0]
+        elif len(maybe_corner) == 1:
+            corner = maybe_corner[0]
         def phys_ident(side, phy_side):
             return to_rust_ident(name.replace(side, phy_side).replace("inset-", ""))
     %>
@@ -860,6 +864,15 @@
                 }
             % endfor
         }
+    % elif corner is not None:
+        use crate::logical_geometry::PhysicalCorner;
+        match wm.${to_rust_ident(corner)}_physical_corner() {
+            % for phy_corner in PHYSICAL_CORNERS:
+                PhysicalCorner::${to_camel_case(phy_corner)} => {
+                    ${caller.inner(physical_ident=phys_ident(corner, phy_corner))}
+                }
+            % endfor
+        }
     % elif size is not None:
         <%
             # (horizontal, vertical)