--- a/layout/style/nsCSSPropList.h
+++ b/layout/style/nsCSSPropList.h
@@ -488,17 +488,18 @@ CSS_PROP_SHORTHAND(
     "")
 CSS_PROP_BACKGROUND(
     background-attachment,
     background_attachment,
     BackgroundAttachment,
     CSS_PROPERTY_PARSE_VALUE_LIST |
         CSS_PROPERTY_APPLIES_TO_FIRST_LETTER_AND_FIRST_LINE |
         CSS_PROPERTY_APPLIES_TO_PLACEHOLDER |
-        CSS_PROPERTY_VALUE_LIST_USES_COMMAS,
+        CSS_PROPERTY_VALUE_LIST_USES_COMMAS |
+        CSS_PROPERTY_APPLIES_TO_CUE,
     "",
     VARIANT_KEYWORD, // used by list parsing
     kImageLayerAttachmentKTable,
     CSS_PROP_NO_OFFSET,
     eStyleAnimType_Discrete)
 CSS_PROP_BACKGROUND(
     background-blend-mode,
     background_blend_mode,
@@ -514,59 +515,63 @@ CSS_PROP_BACKGROUND(
     eStyleAnimType_Discrete)
 CSS_PROP_BACKGROUND(
     background-clip,
     background_clip,
     BackgroundClip,
     CSS_PROPERTY_PARSE_VALUE_LIST |
         CSS_PROPERTY_APPLIES_TO_FIRST_LETTER_AND_FIRST_LINE |
         CSS_PROPERTY_APPLIES_TO_PLACEHOLDER |
-        CSS_PROPERTY_VALUE_LIST_USES_COMMAS,
+        CSS_PROPERTY_VALUE_LIST_USES_COMMAS |
+        CSS_PROPERTY_APPLIES_TO_CUE,
     "",
     VARIANT_KEYWORD, // used by list parsing
     kBackgroundClipKTable,
     CSS_PROP_NO_OFFSET,
     eStyleAnimType_Discrete)
 CSS_PROP_BACKGROUND(
     background-color,
     background_color,
     BackgroundColor,
     CSS_PROPERTY_PARSE_VALUE |
         CSS_PROPERTY_APPLIES_TO_FIRST_LETTER_AND_FIRST_LINE |
         CSS_PROPERTY_APPLIES_TO_PLACEHOLDER |
         CSS_PROPERTY_IGNORED_WHEN_COLORS_DISABLED |
-        CSS_PROPERTY_HASHLESS_COLOR_QUIRK,
+        CSS_PROPERTY_HASHLESS_COLOR_QUIRK |
+        CSS_PROPERTY_APPLIES_TO_CUE,
     "",
     VARIANT_HC,
     nullptr,
     offsetof(nsStyleBackground, mBackgroundColor),
     eStyleAnimType_ComplexColor)
 CSS_PROP_BACKGROUND(
     background-image,
     background_image,
     BackgroundImage,
     CSS_PROPERTY_PARSE_VALUE_LIST |
         CSS_PROPERTY_APPLIES_TO_FIRST_LETTER_AND_FIRST_LINE |
         CSS_PROPERTY_APPLIES_TO_PLACEHOLDER |
         CSS_PROPERTY_VALUE_LIST_USES_COMMAS |
         CSS_PROPERTY_IGNORED_WHEN_COLORS_DISABLED |
-        CSS_PROPERTY_START_IMAGE_LOADS,
+        CSS_PROPERTY_START_IMAGE_LOADS |
+        CSS_PROPERTY_APPLIES_TO_CUE,
     "",
     VARIANT_IMAGE, // used by list parsing
     nullptr,
     CSS_PROP_NO_OFFSET,
     eStyleAnimType_Discrete)
 CSS_PROP_BACKGROUND(
     background-origin,
     background_origin,
     BackgroundOrigin,
     CSS_PROPERTY_PARSE_VALUE_LIST |
         CSS_PROPERTY_APPLIES_TO_FIRST_LETTER_AND_FIRST_LINE |
         CSS_PROPERTY_APPLIES_TO_PLACEHOLDER |
-        CSS_PROPERTY_VALUE_LIST_USES_COMMAS,
+        CSS_PROPERTY_VALUE_LIST_USES_COMMAS |
+        CSS_PROPERTY_APPLIES_TO_CUE,
     "",
     VARIANT_KEYWORD, // used by list parsing
     kBackgroundOriginKTable,
     CSS_PROP_NO_OFFSET,
     eStyleAnimType_Discrete)
 CSS_PROP_SHORTHAND(
     background-position,
     background_position,
@@ -577,59 +582,63 @@ CSS_PROP_SHORTHAND(
 CSS_PROP_BACKGROUND(
     background-position-x,
     background_position_x,
     BackgroundPositionX,
     CSS_PROPERTY_PARSE_FUNCTION |
         CSS_PROPERTY_APPLIES_TO_FIRST_LETTER_AND_FIRST_LINE |
         CSS_PROPERTY_APPLIES_TO_PLACEHOLDER |
         CSS_PROPERTY_VALUE_LIST_USES_COMMAS |
-        CSS_PROPERTY_STORES_CALC,
+        CSS_PROPERTY_STORES_CALC |
+        CSS_PROPERTY_APPLIES_TO_CUE,
     "",
     0,
     kImageLayerPositionKTable,
     CSS_PROP_NO_OFFSET,
     eStyleAnimType_Custom)
 CSS_PROP_BACKGROUND(
     background-position-y,
     background_position_y,
     BackgroundPositionY,
     CSS_PROPERTY_PARSE_FUNCTION |
         CSS_PROPERTY_APPLIES_TO_FIRST_LETTER_AND_FIRST_LINE |
         CSS_PROPERTY_APPLIES_TO_PLACEHOLDER |
         CSS_PROPERTY_VALUE_LIST_USES_COMMAS |
-        CSS_PROPERTY_STORES_CALC,
+        CSS_PROPERTY_STORES_CALC |
+        CSS_PROPERTY_APPLIES_TO_CUE,
     "",
     0,
     kImageLayerPositionKTable,
     CSS_PROP_NO_OFFSET,
     eStyleAnimType_Custom)
 CSS_PROP_BACKGROUND(
     background-repeat,
     background_repeat,
     BackgroundRepeat,
     CSS_PROPERTY_PARSE_FUNCTION |
         CSS_PROPERTY_APPLIES_TO_FIRST_LETTER_AND_FIRST_LINE |
         CSS_PROPERTY_APPLIES_TO_PLACEHOLDER |
-        CSS_PROPERTY_VALUE_LIST_USES_COMMAS,
+        CSS_PROPERTY_VALUE_LIST_USES_COMMAS |
+        CSS_PROPERTY_APPLIES_TO_CUE,
     "",
     VARIANT_KEYWORD, // used by list parsing
     kImageLayerRepeatKTable,
     CSS_PROP_NO_OFFSET,
     eStyleAnimType_Discrete)
 CSS_PROP_BACKGROUND(
     background-size,
     background_size,
     BackgroundSize,
     CSS_PROPERTY_PARSE_FUNCTION |
         CSS_PROPERTY_APPLIES_TO_FIRST_LETTER_AND_FIRST_LINE |
         CSS_PROPERTY_APPLIES_TO_PLACEHOLDER |
         CSS_PROPERTY_VALUE_LIST_USES_COMMAS |
         CSS_PROPERTY_VALUE_NONNEGATIVE |
-        CSS_PROPERTY_STORES_CALC,
+        CSS_PROPERTY_STORES_CALC |
+        CSS_PROPERTY_APPLIES_TO_CUE,
     "",
     0,
     kImageLayerSizeKTable,
     CSS_PROP_NO_OFFSET,
     eStyleAnimType_Custom)
 CSS_PROP_DISPLAY(
     -moz-binding,
     _moz_binding,
@@ -1264,17 +1273,18 @@ CSS_PROP_SHORTHAND(
     "")
 CSS_PROP_POSITION(
     bottom,
     bottom,
     Bottom,
     CSS_PROPERTY_PARSE_VALUE |
         CSS_PROPERTY_STORES_CALC |
         CSS_PROPERTY_UNITLESS_LENGTH_QUIRK |
-        CSS_PROPERTY_GETCS_NEEDS_LAYOUT_FLUSH,
+        CSS_PROPERTY_GETCS_NEEDS_LAYOUT_FLUSH |
+        CSS_PROPERTY_APPLIES_TO_CUE,
     "",
     VARIANT_AHLP | VARIANT_CALC,
     nullptr,
     offsetof(nsStylePosition, mOffset),
     eStyleAnimType_Sides_Bottom)
 CSS_PROP_XUL(
     -moz-box-align,
     _moz_box_align,
@@ -1439,17 +1449,18 @@ CSS_PROP_SVG(
 CSS_PROP_COLOR(
     color,
     color,
     Color,
     CSS_PROPERTY_PARSE_VALUE |
         CSS_PROPERTY_APPLIES_TO_FIRST_LETTER_AND_FIRST_LINE |
         CSS_PROPERTY_APPLIES_TO_PLACEHOLDER |
         CSS_PROPERTY_IGNORED_WHEN_COLORS_DISABLED |
-        CSS_PROPERTY_HASHLESS_COLOR_QUIRK,
+        CSS_PROPERTY_HASHLESS_COLOR_QUIRK |
+        CSS_PROPERTY_APPLIES_TO_CUE,
     "",
     VARIANT_HC,
     nullptr,
     offsetof(nsStyleColor, mColor),
     eStyleAnimType_Color)
 CSS_PROP_VISIBILITY(
     color-adjust,
     color_adjust,
@@ -1851,17 +1862,18 @@ CSS_PROP_SHORTHAND(
     "")
 CSS_PROP_FONT(
     font-family,
     font_family,
     FontFamily,
     CSS_PROPERTY_PARSE_VALUE |
         CSS_PROPERTY_VALUE_PARSER_FUNCTION |
         CSS_PROPERTY_APPLIES_TO_FIRST_LETTER_AND_FIRST_LINE |
-        CSS_PROPERTY_APPLIES_TO_PLACEHOLDER,
+        CSS_PROPERTY_APPLIES_TO_PLACEHOLDER |
+        CSS_PROPERTY_APPLIES_TO_CUE,
     "",
     0,
     nullptr,
     CSS_PROP_NO_OFFSET,
     eStyleAnimType_Discrete)
 CSS_PROP_FONT(
     font-feature-settings,
     font_feature_settings,
@@ -1902,17 +1914,18 @@ CSS_PROP_FONT(
 CSS_PROP_FONT(
     font-size,
     font_size,
     FontSize,
     CSS_PROPERTY_PARSE_VALUE |
         CSS_PROPERTY_VALUE_NONNEGATIVE |
         CSS_PROPERTY_APPLIES_TO_FIRST_LETTER_AND_FIRST_LINE |
         CSS_PROPERTY_APPLIES_TO_PLACEHOLDER |
-        CSS_PROPERTY_UNITLESS_LENGTH_QUIRK,
+        CSS_PROPERTY_UNITLESS_LENGTH_QUIRK |
+        CSS_PROPERTY_APPLIES_TO_CUE,
     "",
     VARIANT_HKLP | VARIANT_SYSFONT | VARIANT_CALC,
     kFontSizeKTable,
     // Note that mSize is the correct place for *reading* the computed value,
     // but setting it requires setting mFont.size as well.
     offsetof(nsStyleFont, mSize),
     eStyleAnimType_nscoord)
 CSS_PROP_FONT(
@@ -1929,29 +1942,31 @@ CSS_PROP_FONT(
     offsetof(nsStyleFont, mFont.sizeAdjust),
     eStyleAnimType_float)
 CSS_PROP_FONT(
     font-stretch,
     font_stretch,
     FontStretch,
     CSS_PROPERTY_PARSE_VALUE |
         CSS_PROPERTY_APPLIES_TO_FIRST_LETTER_AND_FIRST_LINE |
-        CSS_PROPERTY_APPLIES_TO_PLACEHOLDER,
+        CSS_PROPERTY_APPLIES_TO_PLACEHOLDER |
+        CSS_PROPERTY_APPLIES_TO_CUE,
     "",
     VARIANT_HK | VARIANT_SYSFONT,
     kFontStretchKTable,
     offsetof(nsStyleFont, mFont.stretch),
     eStyleAnimType_Custom)
 CSS_PROP_FONT(
     font-style,
     font_style,
     FontStyle,
     CSS_PROPERTY_PARSE_VALUE |
         CSS_PROPERTY_APPLIES_TO_FIRST_LETTER_AND_FIRST_LINE |
-        CSS_PROPERTY_APPLIES_TO_PLACEHOLDER,
+        CSS_PROPERTY_APPLIES_TO_PLACEHOLDER |
+        CSS_PROPERTY_APPLIES_TO_CUE,
     "",
     VARIANT_HK | VARIANT_SYSFONT,
     kFontStyleKTable,
     CSS_PROP_NO_OFFSET,
     eStyleAnimType_Discrete)
 CSS_PROP_FONT(
     font-synthesis,
     font_synthesis,
@@ -1973,107 +1988,115 @@ CSS_PROP_SHORTHAND(
     "")
 CSS_PROP_FONT(
     font-variant-alternates,
     font_variant_alternates,
     FontVariantAlternates,
     CSS_PROPERTY_PARSE_VALUE |
         CSS_PROPERTY_VALUE_PARSER_FUNCTION |
         CSS_PROPERTY_APPLIES_TO_FIRST_LETTER_AND_FIRST_LINE |
-        CSS_PROPERTY_APPLIES_TO_PLACEHOLDER,
+        CSS_PROPERTY_APPLIES_TO_PLACEHOLDER |
+        CSS_PROPERTY_APPLIES_TO_CUE,
     "",
     0,
     kFontVariantAlternatesKTable,
     CSS_PROP_NO_OFFSET,
     eStyleAnimType_Discrete)
 CSS_PROP_FONT(
     font-variant-caps,
     font_variant_caps,
     FontVariantCaps,
     CSS_PROPERTY_PARSE_VALUE |
         CSS_PROPERTY_APPLIES_TO_FIRST_LETTER_AND_FIRST_LINE |
-        CSS_PROPERTY_APPLIES_TO_PLACEHOLDER,
+        CSS_PROPERTY_APPLIES_TO_PLACEHOLDER |
+        CSS_PROPERTY_APPLIES_TO_CUE,
     "",
     VARIANT_HMK,
     kFontVariantCapsKTable,
     CSS_PROP_NO_OFFSET,
     eStyleAnimType_Discrete)
 CSS_PROP_FONT(
     font-variant-east-asian,
     font_variant_east_asian,
     FontVariantEastAsian,
     CSS_PROPERTY_PARSE_VALUE |
         CSS_PROPERTY_VALUE_PARSER_FUNCTION |
         CSS_PROPERTY_APPLIES_TO_FIRST_LETTER_AND_FIRST_LINE |
-        CSS_PROPERTY_APPLIES_TO_PLACEHOLDER,
+        CSS_PROPERTY_APPLIES_TO_PLACEHOLDER |
+        CSS_PROPERTY_APPLIES_TO_CUE,
     "",
     0,
     kFontVariantEastAsianKTable,
     CSS_PROP_NO_OFFSET,
     eStyleAnimType_Discrete)
 CSS_PROP_FONT(
     font-variant-ligatures,
     font_variant_ligatures,
     FontVariantLigatures,
     CSS_PROPERTY_PARSE_VALUE |
         CSS_PROPERTY_VALUE_PARSER_FUNCTION |
         CSS_PROPERTY_APPLIES_TO_FIRST_LETTER_AND_FIRST_LINE |
-        CSS_PROPERTY_APPLIES_TO_PLACEHOLDER,
+        CSS_PROPERTY_APPLIES_TO_PLACEHOLDER |
+        CSS_PROPERTY_APPLIES_TO_CUE,
     "",
     0,
     kFontVariantLigaturesKTable,
     CSS_PROP_NO_OFFSET,
     eStyleAnimType_Discrete)
 CSS_PROP_FONT(
     font-variant-numeric,
     font_variant_numeric,
     FontVariantNumeric,
     CSS_PROPERTY_PARSE_VALUE |
         CSS_PROPERTY_VALUE_PARSER_FUNCTION |
         CSS_PROPERTY_APPLIES_TO_FIRST_LETTER_AND_FIRST_LINE |
-        CSS_PROPERTY_APPLIES_TO_PLACEHOLDER,
+        CSS_PROPERTY_APPLIES_TO_PLACEHOLDER |
+        CSS_PROPERTY_APPLIES_TO_CUE,
     "",
     0,
     kFontVariantNumericKTable,
     CSS_PROP_NO_OFFSET,
     eStyleAnimType_Discrete)
 CSS_PROP_FONT(
     font-variant-position,
     font_variant_position,
     FontVariantPosition,
     CSS_PROPERTY_PARSE_VALUE |
         CSS_PROPERTY_APPLIES_TO_FIRST_LETTER_AND_FIRST_LINE |
-        CSS_PROPERTY_APPLIES_TO_PLACEHOLDER,
+        CSS_PROPERTY_APPLIES_TO_PLACEHOLDER |
+        CSS_PROPERTY_APPLIES_TO_CUE,
     "",
     VARIANT_HMK,
     kFontVariantPositionKTable,
     CSS_PROP_NO_OFFSET,
     eStyleAnimType_Discrete)
 CSS_PROP_FONT(
     font-variation-settings,
     font_variation_settings,
     FontVariationSettings,
     CSS_PROPERTY_PARSE_VALUE |
         CSS_PROPERTY_VALUE_PARSER_FUNCTION |
         CSS_PROPERTY_VALUE_LIST_USES_COMMAS |
         CSS_PROPERTY_APPLIES_TO_FIRST_LETTER_AND_FIRST_LINE |
-        CSS_PROPERTY_APPLIES_TO_PLACEHOLDER,
+        CSS_PROPERTY_APPLIES_TO_PLACEHOLDER |
+        CSS_PROPERTY_APPLIES_TO_CUE,
     "layout.css.font-variations.enabled",
     0,
     nullptr,
     CSS_PROP_NO_OFFSET,
     eStyleAnimType_Custom)
 CSS_PROP_FONT(
     font-weight,
     font_weight,
     FontWeight,
     CSS_PROPERTY_PARSE_VALUE |
         CSS_PROPERTY_VALUE_PARSER_FUNCTION |
         CSS_PROPERTY_APPLIES_TO_FIRST_LETTER_AND_FIRST_LINE |
-        CSS_PROPERTY_APPLIES_TO_PLACEHOLDER,
+        CSS_PROPERTY_APPLIES_TO_PLACEHOLDER |
+        CSS_PROPERTY_APPLIES_TO_CUE,
         // NOTE: This property has range restrictions on interpolation!
     "",
     0,
     kFontWeightKTable,
     offsetof(nsStyleFont, mFont.weight),
     eStyleAnimType_Custom)
 CSS_PROP_UIRESET(
     -moz-force-broken-image-icon,
@@ -2261,17 +2284,18 @@ CSS_PROP_POSITION(
 CSS_PROP_POSITION(
     height,
     height,
     Height,
     CSS_PROPERTY_PARSE_VALUE |
         CSS_PROPERTY_VALUE_NONNEGATIVE |
         CSS_PROPERTY_STORES_CALC |
         CSS_PROPERTY_UNITLESS_LENGTH_QUIRK |
-        CSS_PROPERTY_GETCS_NEEDS_LAYOUT_FLUSH,
+        CSS_PROPERTY_GETCS_NEEDS_LAYOUT_FLUSH |
+        CSS_PROPERTY_APPLIES_TO_CUE,
     "",
     VARIANT_AHKLP | VARIANT_CALC,
     kWidthKTable,
     offsetof(nsStylePosition, mHeight),
     eStyleAnimType_Coord)
 CSS_PROP_TEXT(
     hyphens,
     hyphens,
@@ -2410,17 +2434,18 @@ CSS_PROP_FONT(
 #endif // CSS_PROP_LIST_ONLY_COMPONENTS_OF_ALL_SHORTHAND
 CSS_PROP_POSITION(
     left,
     left,
     Left,
     CSS_PROPERTY_PARSE_VALUE |
         CSS_PROPERTY_STORES_CALC |
         CSS_PROPERTY_UNITLESS_LENGTH_QUIRK |
-        CSS_PROPERTY_GETCS_NEEDS_LAYOUT_FLUSH,
+        CSS_PROPERTY_GETCS_NEEDS_LAYOUT_FLUSH |
+        CSS_PROPERTY_APPLIES_TO_CUE,
     "",
     VARIANT_AHLP | VARIANT_CALC,
     nullptr,
     offsetof(nsStylePosition, mOffset),
     eStyleAnimType_Sides_Left)
 CSS_PROP_TEXT(
     letter-spacing,
     letter_spacing,
@@ -2447,17 +2472,18 @@ CSS_PROP_SVGRESET(
 CSS_PROP_TEXT(
     line-height,
     line_height,
     LineHeight,
     CSS_PROPERTY_PARSE_VALUE |
         CSS_PROPERTY_VALUE_NONNEGATIVE |
         CSS_PROPERTY_APPLIES_TO_FIRST_LETTER_AND_FIRST_LINE |
         CSS_PROPERTY_APPLIES_TO_PLACEHOLDER |
-        CSS_PROPERTY_GETCS_NEEDS_LAYOUT_FLUSH,
+        CSS_PROPERTY_GETCS_NEEDS_LAYOUT_FLUSH |
+        CSS_PROPERTY_APPLIES_TO_CUE,
     "",
     VARIANT_HLPN | VARIANT_KEYWORD | VARIANT_NORMAL | VARIANT_SYSFONT | VARIANT_CALC,
     kLineHeightKTable,
     offsetof(nsStyleText, mLineHeight),
     eStyleAnimType_Coord)
 CSS_PROP_SHORTHAND(
     list-style,
     list_style,
@@ -3075,17 +3101,18 @@ CSS_PROP_LOGICAL(
     eStyleAnimType_None)
 CSS_PROP_EFFECTS(
     opacity,
     opacity,
     Opacity,
     CSS_PROPERTY_PARSE_VALUE |
         CSS_PROPERTY_APPLIES_TO_PLACEHOLDER |
         CSS_PROPERTY_CAN_ANIMATE_ON_COMPOSITOR |
-        CSS_PROPERTY_CREATES_STACKING_CONTEXT,
+        CSS_PROPERTY_CREATES_STACKING_CONTEXT |
+        CSS_PROPERTY_APPLIES_TO_CUE,
     "",
     VARIANT_HN,
     nullptr,
     offsetof(nsStyleEffects, mOpacity),
     eStyleAnimType_float)
 CSS_PROP_POSITION(
     order,
     order,
@@ -3124,17 +3151,18 @@ CSS_PROP_SHORTHAND(
     Outline,
     CSS_PROPERTY_PARSE_FUNCTION,
     "")
 CSS_PROP_OUTLINE(
     outline-color,
     outline_color,
     OutlineColor,
     CSS_PROPERTY_PARSE_VALUE |
-        CSS_PROPERTY_IGNORED_WHEN_COLORS_DISABLED,
+        CSS_PROPERTY_IGNORED_WHEN_COLORS_DISABLED |
+        CSS_PROPERTY_APPLIES_TO_CUE,
     "",
     VARIANT_HC,
     nullptr,
     offsetof(nsStyleOutline, mOutlineColor),
     eStyleAnimType_ComplexColor)
 CSS_PROP_OUTLINE(
     outline-offset,
     outline_offset,
@@ -3198,28 +3226,30 @@ CSS_PROP_OUTLINE(
     0,
     nullptr,
     offsetof(nsStyleOutline, mOutlineRadius),
     eStyleAnimType_Corner_TopRight)
 CSS_PROP_OUTLINE(
     outline-style,
     outline_style,
     OutlineStyle,
-    CSS_PROPERTY_PARSE_VALUE,
+    CSS_PROPERTY_PARSE_VALUE |
+        CSS_PROPERTY_APPLIES_TO_CUE,
     "",
     VARIANT_HK,
     kOutlineStyleKTable,
     CSS_PROP_NO_OFFSET,
     eStyleAnimType_Discrete)
 CSS_PROP_OUTLINE(
     outline-width,
     outline_width,
     OutlineWidth,
     CSS_PROPERTY_PARSE_VALUE |
-        CSS_PROPERTY_VALUE_NONNEGATIVE,
+        CSS_PROPERTY_VALUE_NONNEGATIVE |
+        CSS_PROPERTY_APPLIES_TO_CUE,
     "",
     VARIANT_HKL | VARIANT_CALC,
     kBorderWidthKTable,
     offsetof(nsStyleOutline, mOutlineWidth),
     eStyleAnimType_nscoord)
 CSS_PROP_SHORTHAND(
     overflow,
     overflow,
@@ -3513,17 +3543,18 @@ CSS_PROP_USERINTERFACE(
     eStyleAnimType_Discrete)
 CSS_PROP_DISPLAY(
     position,
     position,
     Position,
     CSS_PROPERTY_PARSE_VALUE |
         // For position: sticky/fixed
         CSS_PROPERTY_CREATES_STACKING_CONTEXT |
-        CSS_PROPERTY_ABSPOS_CB,
+        CSS_PROPERTY_ABSPOS_CB |
+        CSS_PROPERTY_APPLIES_TO_CUE,
     "",
     VARIANT_HK,
     kPositionKTable,
     CSS_PROP_NO_OFFSET,
     eStyleAnimType_Discrete)
 CSS_PROP_LIST(
     quotes,
     quotes,
@@ -3550,17 +3581,18 @@ CSS_PROP_DISPLAY(
     eStyleAnimType_Discrete)
 CSS_PROP_POSITION(
     right,
     right,
     Right,
     CSS_PROPERTY_PARSE_VALUE |
         CSS_PROPERTY_STORES_CALC |
         CSS_PROPERTY_UNITLESS_LENGTH_QUIRK |
-        CSS_PROPERTY_GETCS_NEEDS_LAYOUT_FLUSH,
+        CSS_PROPERTY_GETCS_NEEDS_LAYOUT_FLUSH |
+        CSS_PROPERTY_APPLIES_TO_CUE,
     "",
     VARIANT_AHLP | VARIANT_CALC,
     nullptr,
     offsetof(nsStylePosition, mOffset),
     eStyleAnimType_Sides_Right)
 CSS_PROP_TEXT(
     ruby-align,
     ruby_align,
@@ -3570,17 +3602,18 @@ CSS_PROP_TEXT(
     VARIANT_HK,
     kRubyAlignKTable,
     CSS_PROP_NO_OFFSET,
     eStyleAnimType_Discrete)
 CSS_PROP_TEXT(
     ruby-position,
     ruby_position,
     RubyPosition,
-    CSS_PROPERTY_PARSE_VALUE,
+    CSS_PROPERTY_PARSE_VALUE |
+        CSS_PROPERTY_APPLIES_TO_CUE,
     "",
     VARIANT_HK,
     kRubyPositionKTable,
     CSS_PROP_NO_OFFSET,
     eStyleAnimType_Discrete)
 #ifndef CSS_PROP_LIST_ONLY_COMPONENTS_OF_ALL_SHORTHAND
 #ifndef CSS_PROP_LIST_EXCLUDE_INTERNAL
 CSS_PROP_FONT(
@@ -3900,17 +3933,18 @@ CSS_PROP_TABLE(
     kTableLayoutKTable,
     CSS_PROP_NO_OFFSET,
     eStyleAnimType_Discrete)
 CSS_PROP_TEXT(
     text-align,
     text_align,
     TextAlign,
     CSS_PROPERTY_PARSE_VALUE | CSS_PROPERTY_VALUE_PARSER_FUNCTION |
-      CSS_PROPERTY_APPLIES_TO_PLACEHOLDER,
+      CSS_PROPERTY_APPLIES_TO_PLACEHOLDER |
+      CSS_PROPERTY_APPLIES_TO_CUE,
     "",
     // When we support aligning on a string, we can parse text-align
     // as a string....
     VARIANT_HK /* | VARIANT_STRING */,
     kTextAlignKTable,
     CSS_PROP_NO_OFFSET,
     eStyleAnimType_Discrete)
 CSS_PROP_TEXT(
@@ -3933,17 +3967,18 @@ CSS_PROP_SVG(
     kTextAnchorKTable,
     CSS_PROP_NO_OFFSET,
     eStyleAnimType_Discrete)
 CSS_PROP_TEXT(
     text-combine-upright,
     text_combine_upright,
     TextCombineUpright,
     CSS_PROPERTY_PARSE_VALUE |
-        CSS_PROPERTY_VALUE_PARSER_FUNCTION,
+        CSS_PROPERTY_VALUE_PARSER_FUNCTION |
+        CSS_PROPERTY_APPLIES_TO_CUE,
     "layout.css.text-combine-upright.enabled",
     0,
     kTextCombineUprightKTable,
     CSS_PROP_NO_OFFSET,
     eStyleAnimType_Discrete)
 CSS_PROP_SHORTHAND(
     text-decoration,
     text_decoration,
@@ -3952,42 +3987,45 @@ CSS_PROP_SHORTHAND(
     "")
 CSS_PROP_TEXTRESET(
     text-decoration-color,
     text_decoration_color,
     TextDecorationColor,
     CSS_PROPERTY_PARSE_VALUE |
         CSS_PROPERTY_APPLIES_TO_FIRST_LETTER_AND_FIRST_LINE |
         CSS_PROPERTY_APPLIES_TO_PLACEHOLDER |
-        CSS_PROPERTY_IGNORED_WHEN_COLORS_DISABLED,
+        CSS_PROPERTY_IGNORED_WHEN_COLORS_DISABLED |
+        CSS_PROPERTY_APPLIES_TO_CUE,
     "",
     VARIANT_HC,
     nullptr,
     offsetof(nsStyleTextReset, mTextDecorationColor),
     eStyleAnimType_ComplexColor)
 CSS_PROP_TEXTRESET(
     text-decoration-line,
     text_decoration_line,
     TextDecorationLine,
     CSS_PROPERTY_PARSE_VALUE |
         CSS_PROPERTY_VALUE_PARSER_FUNCTION |
         CSS_PROPERTY_APPLIES_TO_FIRST_LETTER_AND_FIRST_LINE |
-        CSS_PROPERTY_APPLIES_TO_PLACEHOLDER,
+        CSS_PROPERTY_APPLIES_TO_PLACEHOLDER |
+        CSS_PROPERTY_APPLIES_TO_CUE,
     "",
     0,
     kTextDecorationLineKTable,
     CSS_PROP_NO_OFFSET,
     eStyleAnimType_Discrete)
 CSS_PROP_TEXTRESET(
     text-decoration-style,
     text_decoration_style,
     TextDecorationStyle,
     CSS_PROPERTY_PARSE_VALUE |
         CSS_PROPERTY_APPLIES_TO_FIRST_LETTER_AND_FIRST_LINE |
-        CSS_PROPERTY_APPLIES_TO_PLACEHOLDER,
+        CSS_PROPERTY_APPLIES_TO_PLACEHOLDER |
+        CSS_PROPERTY_APPLIES_TO_CUE,
     "",
     VARIANT_HK,
     kTextDecorationStyleKTable,
     CSS_PROP_NO_OFFSET,
     eStyleAnimType_Discrete)
 CSS_PROP_SHORTHAND(
     text-emphasis,
     text_emphasis,
@@ -4051,17 +4089,18 @@ CSS_PROP_TEXT(
     VARIANT_HLP | VARIANT_CALC,
     nullptr,
     offsetof(nsStyleText, mTextIndent),
     eStyleAnimType_Coord)
 CSS_PROP_VISIBILITY(
     text-orientation,
     text_orientation,
     TextOrientation,
-    CSS_PROPERTY_PARSE_VALUE,
+    CSS_PROPERTY_PARSE_VALUE |
+        CSS_PROPERTY_APPLIES_TO_CUE,
     "",
     VARIANT_HK,
     kTextOrientationKTable,
     CSS_PROP_NO_OFFSET,
     eStyleAnimType_Discrete)
 CSS_PROP_TEXTRESET(
     text-overflow,
     text_overflow,
@@ -4087,17 +4126,18 @@ CSS_PROP_TEXT(
 CSS_PROP_TEXT(
     text-shadow,
     text_shadow,
     TextShadow,
     CSS_PROPERTY_PARSE_FUNCTION |
         CSS_PROPERTY_APPLIES_TO_FIRST_LETTER_AND_FIRST_LINE |
         CSS_PROPERTY_APPLIES_TO_PLACEHOLDER |
         CSS_PROPERTY_VALUE_LIST_USES_COMMAS |
-        CSS_PROPERTY_IGNORED_WHEN_COLORS_DISABLED,
+        CSS_PROPERTY_IGNORED_WHEN_COLORS_DISABLED |
+        CSS_PROPERTY_APPLIES_TO_CUE,
         // NOTE: some components must be nonnegative
     "",
     0,
     nullptr,
     offsetof(nsStyleText, mTextShadow),
     eStyleAnimType_Shadow)
 CSS_PROP_TEXT(
     -moz-text-size-adjust,
@@ -4170,17 +4210,18 @@ CSS_PROP_FONT(
 #endif // CSS_PROP_LIST_ONLY_COMPONENTS_OF_ALL_SHORTHAND
 CSS_PROP_POSITION(
     top,
     top,
     Top,
     CSS_PROPERTY_PARSE_VALUE |
         CSS_PROPERTY_STORES_CALC |
         CSS_PROPERTY_UNITLESS_LENGTH_QUIRK |
-        CSS_PROPERTY_GETCS_NEEDS_LAYOUT_FLUSH,
+        CSS_PROPERTY_GETCS_NEEDS_LAYOUT_FLUSH |
+        CSS_PROPERTY_APPLIES_TO_CUE,
     "",
     VARIANT_AHLP | VARIANT_CALC,
     nullptr,
     offsetof(nsStylePosition, mOffset),
     eStyleAnimType_Sides_Top)
 #ifndef CSS_PROP_LIST_EXCLUDE_INTERNAL
 CSS_PROP_DISPLAY(
     -moz-top-layer,
@@ -4403,31 +4444,33 @@ CSS_PROP_VISIBILITY(
     CSS_PROP_NO_OFFSET,
     eStyleAnimType_Discrete)  // reflow for collapse
 CSS_PROP_TEXT(
     white-space,
     white_space,
     WhiteSpace,
     CSS_PROPERTY_PARSE_VALUE |
         // This is required by the UA stylesheet and can't be overridden.
-        CSS_PROPERTY_APPLIES_TO_PLACEHOLDER,
+        CSS_PROPERTY_APPLIES_TO_PLACEHOLDER |
+        CSS_PROPERTY_APPLIES_TO_CUE,
     "",
     VARIANT_HK,
     kWhitespaceKTable,
     CSS_PROP_NO_OFFSET,
     eStyleAnimType_Discrete)
 CSS_PROP_POSITION(
     width,
     width,
     Width,
     CSS_PROPERTY_PARSE_VALUE |
         CSS_PROPERTY_VALUE_NONNEGATIVE |
         CSS_PROPERTY_STORES_CALC |
         CSS_PROPERTY_UNITLESS_LENGTH_QUIRK |
-        CSS_PROPERTY_GETCS_NEEDS_LAYOUT_FLUSH,
+        CSS_PROPERTY_GETCS_NEEDS_LAYOUT_FLUSH |
+        CSS_PROPERTY_APPLIES_TO_CUE,
     "",
     VARIANT_AHKLP | VARIANT_CALC,
     kWidthKTable,
     offsetof(nsStylePosition, mWidth),
     eStyleAnimType_Coord)
 CSS_PROP_DISPLAY(
     will-change,
     will_change,

--- a/layout/style/nsCSSProps.h
+++ b/layout/style/nsCSSProps.h
@@ -276,16 +276,18 @@ static_assert((CSS_PROPERTY_PARSE_PROPER
 // absolutely positioned elements.
 // This should be set for any properties that can cause an element to be
 // such a containing block, as implemented in
 // nsStyleDisplay::IsAbsPosContainingBlock.
 // It does not need to be set for properties that also have
 // CSS_PROPERTY_FIXPOS_CB set.
 #define CSS_PROPERTY_ABSPOS_CB                    (1<<30)
 
+#define CSS_PROPERTY_APPLIES_TO_CUE               (1U<<31)
+
 /**
  * Types of animatable values.
  */
 enum nsStyleAnimType {
   // requires a custom implementation in
   // StyleAnimationValue::ExtractComputedValue
   eStyleAnimType_Custom,
 

--- a/layout/style/nsRuleNode.cpp
+++ b/layout/style/nsRuleNode.cpp
@@ -2323,16 +2323,18 @@ GetPseudoRestriction(nsStyleContext *aCo
   nsIAtom *pseudoType = aContext->GetPseudo();
   if (pseudoType) {
     if (pseudoType == nsCSSPseudoElements::firstLetter) {
       pseudoRestriction = CSS_PROPERTY_APPLIES_TO_FIRST_LETTER;
     } else if (pseudoType == nsCSSPseudoElements::firstLine) {
       pseudoRestriction = CSS_PROPERTY_APPLIES_TO_FIRST_LINE;
     } else if (pseudoType == nsCSSPseudoElements::placeholder) {
       pseudoRestriction = CSS_PROPERTY_APPLIES_TO_PLACEHOLDER;
+    } else if (pseudoType == nsCSSPseudoElements::cue) {
+      pseudoRestriction = CSS_PROPERTY_APPLIES_TO_CUE;
     }
   }
   return pseudoRestriction;
 }
 
 static void
 UnsetPropertiesWithoutFlags(const nsStyleStructID aSID,
                             nsRuleData* aRuleData,