Fix framework layout and image transforms

crates/obscura-render/src/dom.rs

@@ -3709,6 +3709,84 @@ fn build_any(
     build(tree, id, taffy_tree, id_map, words, engine, ifc_items, styles).into_iter().collect()
 }
 
+/// Build the direct children of a genuine flex/grid container.
+///
+/// CSS wraps every contiguous run of in-flow text in one anonymous flex/grid
+/// item whose contents form an inline formatting context. Splitting a text
+/// node into one taffy item per word is only valid inside our flex-wrap IFC
+/// stand-in; doing it at this outer level makes `flex-wrap:nowrap` lay an
+/// entire paragraph on one line (MDN's contributor quote). Fold text runs to
+/// one measured/shaped anonymous item and leave authored element children as
+/// their own flex/grid items.
+#[allow(clippy::too_many_arguments)]
+fn build_flex_grid_children(
+    tree: &DomTree,
+    parent: NodeId,
+    dom_children: &[NodeId],
+    taffy_tree: &mut TaffyTree<usize>,
+    id_map: &mut HashMap<taffy::NodeId, NodeId>,
+    words: &mut HashMap<taffy::NodeId, (NodeId, String)>,
+    engine: &mut crate::inline::TextEngine,
+    ifc_items: &mut IfcRegistry,
+    styles: &HashMap<NodeId, crate::LayoutStyle>,
+) -> Vec<taffy::NodeId> {
+    let mut children = Vec::new();
+    let mut index = 0;
+    while index < dom_children.len() {
+        let is_text = tree.get_node(dom_children[index]).map_or(false, |node| {
+            matches!(node.data, obscura_dom::tree::NodeData::Text { .. })
+        });
+        if !is_text {
+            children.extend(build_any(
+                tree,
+                dom_children[index],
+                taffy_tree,
+                id_map,
+                words,
+                engine,
+                ifc_items,
+                styles,
+            ));
+            index += 1;
+            continue;
+        }
+
+        let start = index;
+        while index < dom_children.len()
+            && tree.get_node(dom_children[index]).map_or(false, |node| {
+                matches!(node.data, obscura_dom::tree::NodeData::Text { .. })
+            })
+        {
+            index += 1;
+        }
+        let run = &dom_children[start..index];
+        if let Some(item) = engine.try_build_run(tree, parent, run, styles) {
+            let style = taffy::Style {
+                display: taffy::style::Display::Block,
+                ..Default::default()
+            };
+            if let Ok(leaf) = taffy_tree.new_leaf_with_context(style, item) {
+                ifc_items.runs.entry(parent).or_default().push(item);
+                children.push(leaf);
+                continue;
+            }
+        }
+        for &text in run {
+            children.extend(build_any(
+                tree,
+                text,
+                taffy_tree,
+                id_map,
+                words,
+                engine,
+                ifc_items,
+                styles,
+            ));
+        }
+    }
+    children
+}
+
 /// Is `id` a `display: inline` element with no box appearance or sizing of
 /// its own — safe to flatten into its parent's child list instead of giving
 /// it an independent (and, for wrapping auto-width containers, buggy) flex
@@ -4862,6 +4940,20 @@ fn build(
 
     let mut child_ids: Vec<taffy::NodeId> = if has_float_child {
         build_children_with_float_zone(tree, id, &dom_children, taffy_tree, id_map, words, engine, ifc_items, styles)
+    } else if matches!(style.display, crate::Display::Flex | crate::Display::Grid)
+        && !style.internal_flex_container
+    {
+        build_flex_grid_children(
+            tree,
+            id,
+            &dom_children,
+            taffy_tree,
+            id_map,
+            words,
+            engine,
+            ifc_items,
+            styles,
+        )
     } else {
         dom_children.into_iter().flat_map(|cid| build_any(tree, cid, taffy_tree, id_map, words, engine, ifc_items, styles)).collect()
     };
@@ -6236,6 +6328,26 @@ mod tests {
         assert!((second.y - first.y - 100.0).abs() < 0.1, "{second:?}");
     }
 
+    #[test]
+    fn direct_flex_text_is_one_wrapping_anonymous_item() {
+        // Chromium 140: the pseudo is one flex item and the direct text run
+        // is one anonymous flex item with a 276px inline formatting context.
+        // The sentence wraps to three 20px lines; treating every word as an
+        // outer flex item instead produces one overflowing 20px line.
+        let tree = parse_html(
+            "<style>\
+             *{box-sizing:border-box}body{margin:0}\
+             #quote{display:flex;gap:8px;width:300px;font:16px/20px 'Liberation Sans'}\
+             #quote::before{content:'';display:block;width:16px;height:16px;flex-shrink:0}\
+             </style>\
+             <div id=\"quote\">This anonymous text item must wrap inside the remaining flex space instead of overflowing.</div>",
+        );
+        let laid = layout_dom(&tree, (500.0, 200.0));
+        let quote = laid.rects[&tree.get_element_by_id("quote").unwrap()];
+        assert!((quote.width - 300.0).abs() < 0.1, "{quote:?}");
+        assert!((quote.height - 60.0).abs() < 0.1, "{quote:?}");
+    }
+
     #[test]
     fn empty_document_is_safe() {
         // html5ever always synthesizes html/head/body, so an empty document
@@ -6360,20 +6472,11 @@ mod tests {
         let tree = parse_html(
             r#"<div id="cta" style="display:flex;text-transform:uppercase">get started</div>"#,
         );
-        let text = tree
-            .descendants(tree.document())
-            .into_iter()
-            .find(|id| tree.get_node(*id).is_some_and(|node| node.is_text()))
-            .unwrap();
         let laid = layout_dom(&tree, (1280.0, 720.0));
-        let painted = laid
+        let cta = tree.get_element_by_id("cta").unwrap();
-            .text_runs
+        let items = &laid.run_ifc_items[&cta];
-            .get(&text)
+        assert_eq!(items.len(), 1);
-            .unwrap()
+        assert_eq!(laid.text_engine.item_text(items[0]), "GET STARTED");
-            .iter()
-            .map(|(_, word)| word.as_str())
-            .collect::<String>();
-        assert_eq!(painted, "GET STARTED");
         assert_eq!(
             transform_word_leaf_text("hELLO wORLD", crate::TextTransform::Capitalize),
             "HELLO WORLD"
@@ -6383,17 +6486,14 @@ mod tests {
     #[test]
     fn word_leaves_use_the_computed_line_height() {
         let tree = parse_html(
-            r#"<div style="display:flex;font:16px/32px monospace">code</div>"#,
+            r#"<div id="code" style="display:flex;font:16px/32px monospace">code</div>"#,
         );
-        let text = tree
+        let mut laid = layout_dom(&tree, (1280.0, 720.0));
-            .descendants(tree.document())
+        let code = tree.get_element_by_id("code").unwrap();
-            .into_iter()
+        let items = &laid.run_ifc_items[&code];
-            .find(|id| tree.get_node(*id).is_some_and(|node| node.is_text()))
+        assert_eq!(items.len(), 1);
-            .unwrap();
+        let (_, height) = laid.text_engine.measure(items[0], Some(1280.0));
-        let laid = layout_dom(&tree, (1280.0, 720.0));
+        assert_eq!(height, 32.0);
-        let runs = laid.text_runs.get(&text).unwrap();
-        assert_eq!(runs.len(), 1);
-        assert_eq!(runs[0].0.height, 32.0);
     }
 
     #[test]

crates/obscura-render/src/inline.rs

@@ -563,6 +563,16 @@ impl TextEngine {
         self.items.is_empty()
     }
 
+    #[cfg(test)]
+    pub(crate) fn item_text(&self, idx: usize) -> String {
+        self.items[idx]
+            .buffer
+            .lines
+            .iter()
+            .map(|line| line.text())
+            .collect()
+    }
+
     /// Build an inline formatting context for `id`'s subtree if it is one we
     /// can collapse to shaped text (see [`is_pure_text_ifc`]); returns the
     /// item index to store as the leaf's taffy context. `None` means the

crates/obscura-render/src/lib.rs

@@ -577,12 +577,19 @@ pub struct LayoutStyle {
     /// absolute and fixed descendants. Kept as a bitset so `filter:none`
     /// cannot clear a transform/containment trigger from another property.
     pub containing_block_triggers: u16,
-    /// `transform: scale(sx[, sy])` / `scaleX` / `scaleY`, captured as (sx, sy).
+    /// `transform: scale(sx[, sy])` / `scaleX` / `scaleY`, or the individual
-    /// Parsed and stored so a value that mixes scale with translate still yields
+    /// `scale` property, captured as (sx, sy). Raster-image paint applies it to
-    /// its translate part; scale is not yet folded into paint geometry (doing so
+    /// the element's subtree together with [`LayoutStyle::transform_projection`].
-    /// correctly would require scaling every descendant's size and text, outside
-    /// the paint-time translate-offset model used here).
     pub transform_scale: Option<(f32, f32)>,
+    /// The affine x/y projection of authored `rotate`, `rotateX`, `rotateY`,
+    /// and `rotateZ` transform functions. CSS transforms without perspective
+    /// remain affine when their input plane has z=0, so this preserves modern
+    /// 3D-tilted image cards without introducing a full scene graph.
+    /// Stored as `[a, b, c, d]` for `x'=a*x+c*y`, `y'=b*x+d*y`.
+    pub transform_projection: Option<[f32; 4]>,
+    /// Authored `transform-origin`, unresolved so percentages use the final
+    /// border-box dimensions. `None` is the CSS initial value, 50% 50%.
+    pub transform_origin: Option<(Dimension, Dimension)>,
     /// `box-shadow` (first layer only). Painted behind the element's own
     /// background/border box: cards, buttons, menus, and modals across the
     /// modern web rely on it for depth, and without it those elements paint

crates/obscura-render/src/paint.rs

@@ -74,6 +74,10 @@ pub fn paint_dom_scrolled(
         laid = layout_dom_with_web_fonts(tree, viewport, &intrinsic, &fonts);
     }
     apply_document_scroll(tree, &mut laid, viewport, scroll);
+    // Only raster images inside an actually rotated/scaled subtree receive an
+    // affine entry. Ordinary pages pay one fast style scan and allocate no
+    // matrix map; transformed pages do matrix work only along those subtrees.
+    let projected_images = collect_projected_image_transforms(tree, &laid);
     let root_font_size = tree
         .query_selector("html")
         .ok()
@@ -251,12 +255,16 @@ pub fn paint_dom_scrolled(
         // ubiquitous 1x1 clipped "visually hidden" accessibility pattern
         // actually invisible instead of painting text wherever it lands).
         let clip = laid.clip_rects.get(&nid).copied().flatten();
+        let projected_image = projected_images.get(&nid).copied();
+        let cull_rect = projected_image
+            .map(|transform| transform.map_rect(rect))
+            .unwrap_or(rect);
         let visible_rect = match clip {
-            Some(c) => match rect.intersect(&c) {
+            Some(c) => match cull_rect.intersect(&c) {
                 Some(r) => r,
                 None => continue,
             },
-            None => rect,
+            None => cull_rect,
         };
         let box_rect = match Rect::from_xywh(visible_rect.x, visible_rect.y, visible_rect.width, visible_rect.height) {
             Some(r) => r,
@@ -365,6 +373,7 @@ pub fn paint_dom_scrolled(
                         crate::ObjectFit::Fill,
                         &mut pixmap,
                         &mut image_cache,
+                        None,
                     );
                 }
             }
@@ -447,7 +456,16 @@ pub fn paint_dom_scrolled(
                 // half-scrolled carousel slide's image otherwise bleeds over
                 // the viewport edge).
                 let painted =
-                    paint_image(&src, base_url, &rect, &visible_rect, style.object_fit, &mut pixmap, &mut image_cache);
+                    paint_image(
+                        &src,
+                        base_url,
+                        &rect,
+                        &visible_rect,
+                        style.object_fit,
+                        &mut pixmap,
+                        &mut image_cache,
+                        projected_image,
+                    );
                 // Fall back when the image itself did not paint, following
                 // what browsers show for a broken image: a non-empty alt
                 // renders as text in place of the image (no placeholder box),
@@ -768,6 +786,175 @@ fn apply_document_scroll(
     }
 }
 
+#[derive(Clone, Copy, Debug)]
+struct ImageAffine {
+    a: f32,
+    b: f32,
+    c: f32,
+    d: f32,
+    e: f32,
+    f: f32,
+}
+
+impl ImageAffine {
+    const IDENTITY: Self = Self {
+        a: 1.0,
+        b: 0.0,
+        c: 0.0,
+        d: 1.0,
+        e: 0.0,
+        f: 0.0,
+    };
+
+    /// Compose `self(other(point))`.
+    fn then(self, other: Self) -> Self {
+        Self {
+            a: self.a * other.a + self.c * other.b,
+            b: self.b * other.a + self.d * other.b,
+            c: self.a * other.c + self.c * other.d,
+            d: self.b * other.c + self.d * other.d,
+            e: self.a * other.e + self.c * other.f + self.e,
+            f: self.b * other.e + self.d * other.f + self.f,
+        }
+    }
+
+    fn around(origin: (f32, f32), linear: [f32; 4]) -> Self {
+        let [a, b, c, d] = linear;
+        Self {
+            a,
+            b,
+            c,
+            d,
+            e: origin.0 - a * origin.0 - c * origin.1,
+            f: origin.1 - b * origin.0 - d * origin.1,
+        }
+    }
+
+    fn map(self, x: f32, y: f32) -> (f32, f32) {
+        (
+            self.a * x + self.c * y + self.e,
+            self.b * x + self.d * y + self.f,
+        )
+    }
+
+    fn map_rect(self, rect: crate::Rect) -> crate::Rect {
+        let points = [
+            self.map(rect.x, rect.y),
+            self.map(rect.x + rect.width, rect.y),
+            self.map(rect.x, rect.y + rect.height),
+            self.map(rect.x + rect.width, rect.y + rect.height),
+        ];
+        let left = points.iter().map(|point| point.0).fold(f32::INFINITY, f32::min);
+        let top = points.iter().map(|point| point.1).fold(f32::INFINITY, f32::min);
+        let right = points
+            .iter()
+            .map(|point| point.0)
+            .fold(f32::NEG_INFINITY, f32::max);
+        let bottom = points
+            .iter()
+            .map(|point| point.1)
+            .fold(f32::NEG_INFINITY, f32::max);
+        crate::Rect {
+            x: left,
+            y: top,
+            width: (right - left).max(0.0),
+            height: (bottom - top).max(0.0),
+        }
+    }
+
+    fn tiny_skia(self) -> Transform {
+        Transform::from_row(self.a, self.b, self.c, self.d, self.e, self.f)
+    }
+
+    fn is_identity(self) -> bool {
+        (self.a - 1.0).abs() < f32::EPSILON
+            && self.b.abs() < f32::EPSILON
+            && self.c.abs() < f32::EPSILON
+            && (self.d - 1.0).abs() < f32::EPSILON
+            && self.e.abs() < f32::EPSILON
+            && self.f.abs() < f32::EPSILON
+    }
+}
+
+/// Accumulate rotation/scale matrices through transformed subtrees, storing
+/// entries only for raster `<img>` descendants. Translation remains on
+/// `DomLayout::translates`, whose offsets already include root scroll.
+fn collect_projected_image_transforms(
+    tree: &DomTree,
+    layout: &crate::DomLayout,
+) -> std::collections::HashMap<obscura_dom::tree::NodeId, ImageAffine> {
+    if !layout.styles.values().any(|style| {
+        style.transform_projection.is_some() || style.transform_scale.is_some()
+    }) {
+        return std::collections::HashMap::new();
+    }
+
+    fn walk(
+        tree: &DomTree,
+        layout: &crate::DomLayout,
+        id: obscura_dom::tree::NodeId,
+        parent: ImageAffine,
+        active: bool,
+        out: &mut std::collections::HashMap<obscura_dom::tree::NodeId, ImageAffine>,
+    ) {
+        let style = layout.styles.get(&id);
+        let own_active = style.is_some_and(|style| {
+            style.transform_projection.is_some() || style.transform_scale.is_some()
+        });
+        let mut combined = parent;
+        if own_active {
+            let style = style.unwrap();
+            let projection = style
+                .transform_projection
+                .unwrap_or([1.0, 0.0, 0.0, 1.0]);
+            let (scale_x, scale_y) = style.transform_scale.unwrap_or((1.0, 1.0));
+            let linear = [
+                scale_x * projection[0],
+                scale_y * projection[1],
+                scale_x * projection[2],
+                scale_y * projection[3],
+            ];
+            if let Some(rect) = layout.rects.get(&id) {
+                let offset = layout.translates.get(&id).copied().unwrap_or((0.0, 0.0));
+                let (origin_x, origin_y) = style.transform_origin.unwrap_or((
+                    crate::Dimension::Percent(0.5),
+                    crate::Dimension::Percent(0.5),
+                ));
+                let origin = (
+                    rect.x + offset.0 + crate::dom::resolve_translate(origin_x, rect.width),
+                    rect.y + offset.1 + crate::dom::resolve_translate(origin_y, rect.height),
+                );
+                combined = parent.then(ImageAffine::around(origin, linear));
+            }
+        }
+
+        let transformed = active || own_active;
+        if transformed
+            && !combined.is_identity()
+            && tree.get_node(id).is_some_and(|node| {
+                node.as_element()
+                    .is_some_and(|element| element.local.as_ref() == "img")
+            })
+        {
+            out.insert(id, combined);
+        }
+        for child in tree.children(id) {
+            walk(tree, layout, child, combined, transformed, out);
+        }
+    }
+
+    let mut out = std::collections::HashMap::new();
+    walk(
+        tree,
+        layout,
+        tree.document(),
+        ImageAffine::IDENTITY,
+        false,
+        &mut out,
+    );
+    out
+}
+
 /// A closed rounded-rectangle path, corners approximated by quadratic curves
 /// (visually indistinguishable from true arcs at typical UI radii). `r` is
 /// clamped so it never exceeds half the shorter side.
@@ -2155,6 +2342,7 @@ fn paint_in_flow_generated_box(
                 crate::ObjectFit::Fill,
                 pixmap,
                 image_cache,
+                None,
             );
         }
     }
@@ -2343,6 +2531,7 @@ fn paint_positioned_pseudo(
                 crate::ObjectFit::Fill,
                 pixmap,
                 image_cache,
+                None,
             );
         }
     }
@@ -2694,6 +2883,7 @@ fn paint_image(
     object_fit: crate::ObjectFit,
     pixmap: &mut Pixmap,
     cache: &mut std::collections::HashMap<String, Option<Vec<u8>>>,
+    transform: Option<ImageAffine>,
 ) -> bool {
     if rect.width <= 0.0 || rect.height <= 0.0 {
         return false;
@@ -2745,7 +2935,9 @@ fn paint_image(
         dest.y as i32,
         content.as_ref(),
         &tiny_skia::PixmapPaint::default(),
-        Transform::identity(),
+        transform
+            .map(ImageAffine::tiny_skia)
+            .unwrap_or_else(Transform::identity),
         clip.as_ref(),
     );
     true
@@ -4175,6 +4367,39 @@ mod tests {
         );
     }
 
+    #[test]
+    fn projected_image_transform_enters_overflow_clip() {
+        // Chromium reduction: without the projected rotate/scale, this image is
+        // wholly left of the clip. Its transformed right edge reaches x=53.14.
+        let tree = parse_html(
+            r#"<html><body style="margin:0">
+               <div style="position:relative;width:120px;height:100px;overflow:hidden">
+                 <div style="position:absolute;left:-60px;top:50px;transform-origin:0 0;
+                             transform:rotateX(60deg) rotateZ(-45deg);scale:200%">
+                   <img alt="" src="data:image/svg+xml,%3Csvg%20xmlns='http://www.w3.org/2000/svg'%20width='40'%20height='40'%3E%3Crect%20width='40'%20height='40'%20fill='red'/%3E%3C/svg%3E"
+                        style="display:block;width:40px;height:40px">
+                 </div>
+               </div>
+               </body></html>"#,
+        );
+        let pixmap = paint_dom(&tree, (160.0, 120.0), None).expect("pixmap");
+
+        assert!(
+            (0..100).any(|y| (0..120).any(|x| {
+                let pixel = pixmap.pixel(x, y).expect("inside viewport");
+                pixel.red() > 220 && pixel.green() < 40 && pixel.blue() < 40
+            })),
+            "projected image should enter the overflow clip"
+        );
+        assert!(
+            (0..120).all(|y| (120..160).all(|x| {
+                let pixel = pixmap.pixel(x, y).expect("outside clip");
+                pixel.red() > 240 && pixel.green() > 240 && pixel.blue() > 240
+            })),
+            "projected image must remain clipped to its overflow ancestor"
+        );
+    }
+
     #[test]
     fn translate_offscreen_box_is_not_painted() {
         // translate(-10000px,0) shoves the box far off the left edge (the old

crates/obscura-render/src/style.rs

@@ -1020,6 +1020,8 @@ fn apply_value(style: &mut LayoutStyle, name: &str, value: &str) {
         "grid-row-start" => set_grid_placement_side(style, value, false, true),
         "grid-row-end" => set_grid_placement_side(style, value, false, false),
         "transform" => parse_transform(style, value),
+        "transform-origin" => style.transform_origin = parse_transform_origin(value),
+        "scale" => parse_individual_scale(style, value),
         "filter" => set_containing_block_trigger(
             style,
             crate::CB_TRIGGER_FILTER,
@@ -1225,6 +1227,8 @@ pub(crate) fn supports_declaration(name: &str, value: &str) -> bool {
             | "grid-row-start"
             | "grid-row-end"
             | "transform"
+            | "transform-origin"
+            | "scale"
             | "filter"
             | "backdrop-filter"
             | "-webkit-backdrop-filter"
@@ -1449,12 +1453,11 @@ fn content_alignment_pair(
     None
 }
 
-/// Parse the subset of `transform` obscura applies at paint time: `translate`,
+/// Parse the transform functions used by the scoped paint model. Translation
-/// `translateX`, `translateY` (px and %, stored unresolved so % can resolve
+/// stays unresolved until the final border box is known. Scale is captured
-/// against the element's own border box later) and `scale`/`scaleX`/`scaleY`.
+/// separately, while rotations are multiplied as 3×3 matrices and projected
-/// `rotate`, `skew`, `matrix`, and `perspective` are ignored (left unhandled)
+/// onto the input z=0 plane; this exactly represents rotateX/Y/Z chains that
-/// rather than erroring, so a value that mixes them still contributes its
+/// do not introduce perspective.
-/// translate and scale parts.
 fn parse_transform(style: &mut LayoutStyle, value: &str) {
     let v = value.trim();
     if v.is_empty() {
@@ -1466,6 +1469,7 @@ fn parse_transform(style: &mut LayoutStyle, value: &str) {
     if v.eq_ignore_ascii_case("none") {
         style.transform_translate = None;
         style.transform_scale = None;
+        style.transform_projection = None;
         set_containing_block_trigger(style, crate::CB_TRIGGER_TRANSFORM, false);
         return;
     }
@@ -1477,6 +1481,12 @@ fn parse_transform(style: &mut LayoutStyle, value: &str) {
     let zero = crate::Dimension::Px(0.0);
     let (mut tx, mut ty): (Option<crate::Dimension>, Option<crate::Dimension>) = (None, None);
     let (mut sx, mut sy): (Option<f32>, Option<f32>) = (None, None);
+    let mut rotation = [
+        1.0f32, 0.0, 0.0,
+        0.0, 1.0, 0.0,
+        0.0, 0.0, 1.0,
+    ];
+    let mut has_rotation = false;
     for (func, args) in functions {
         let parts: Vec<&str> = args.split(',').map(|s| s.trim()).filter(|s| !s.is_empty()).collect();
         match func.to_ascii_lowercase().as_str() {
@@ -1517,7 +1527,27 @@ fn parse_transform(style: &mut LayoutStyle, value: &str) {
                     sy = Some(a);
                 }
             }
-            // rotate / skew / matrix / perspective: not modeled, skip.
+            "rotate" | "rotatez" => {
+                if let Some(angle) = parts.first().and_then(|value| angle_degrees(value)) {
+                    rotation = matrix3_mul(rotation, rotate_z_matrix(angle));
+                    has_rotation = true;
+                }
+            }
+            "rotatex" => {
+                if let Some(angle) = parts.first().and_then(|value| angle_degrees(value)) {
+                    rotation = matrix3_mul(rotation, rotate_x_matrix(angle));
+                    has_rotation = true;
+                }
+            }
+            "rotatey" => {
+                if let Some(angle) = parts.first().and_then(|value| angle_degrees(value)) {
+                    rotation = matrix3_mul(rotation, rotate_y_matrix(angle));
+                    has_rotation = true;
+                }
+            }
+            // Skew, matrix, and perspective remain outside the scoped affine
+            // image projection. Other supported functions in the same value
+            // still take effect.
             _ => {}
         }
     }
@@ -1527,6 +1557,118 @@ fn parse_transform(style: &mut LayoutStyle, value: &str) {
     if sx.is_some() || sy.is_some() {
         style.transform_scale = Some((sx.unwrap_or(1.0), sy.unwrap_or(1.0)));
     }
+    style.transform_projection = has_rotation.then_some([
+        rotation[0],
+        rotation[3],
+        rotation[1],
+        rotation[4],
+    ]);
+}
+
+fn matrix3_mul(left: [f32; 9], right: [f32; 9]) -> [f32; 9] {
+    let mut out = [0.0; 9];
+    for row in 0..3 {
+        for column in 0..3 {
+            out[row * 3 + column] = (0..3)
+                .map(|inner| left[row * 3 + inner] * right[inner * 3 + column])
+                .sum();
+        }
+    }
+    out
+}
+
+fn rotate_x_matrix(angle: f32) -> [f32; 9] {
+    let (sin, cos) = angle.to_radians().sin_cos();
+    [1.0, 0.0, 0.0, 0.0, cos, -sin, 0.0, sin, cos]
+}
+
+fn rotate_y_matrix(angle: f32) -> [f32; 9] {
+    let (sin, cos) = angle.to_radians().sin_cos();
+    [cos, 0.0, sin, 0.0, 1.0, 0.0, -sin, 0.0, cos]
+}
+
+fn rotate_z_matrix(angle: f32) -> [f32; 9] {
+    let (sin, cos) = angle.to_radians().sin_cos();
+    [cos, -sin, 0.0, sin, cos, 0.0, 0.0, 0.0, 1.0]
+}
+
+fn angle_degrees(value: &str) -> Option<f32> {
+    fn primitive(value: &str) -> Option<f32> {
+        let value = value.trim().to_ascii_lowercase();
+        if let Some(number) = value.strip_suffix("deg") {
+            number.trim().parse().ok()
+        } else if let Some(number) = value.strip_suffix("grad") {
+            number.trim().parse::<f32>().ok().map(|value| value * 0.9)
+        } else if let Some(number) = value.strip_suffix("rad") {
+            number
+                .trim()
+                .parse::<f32>()
+                .ok()
+                .map(f32::to_degrees)
+        } else if let Some(number) = value.strip_suffix("turn") {
+            number.trim().parse::<f32>().ok().map(|value| value * 360.0)
+        } else if value == "0" {
+            Some(0.0)
+        } else {
+            None
+        }
+    }
+
+    let value = value.trim();
+    let Some(inner) = value
+        .strip_prefix("calc(")
+        .and_then(|value| value.strip_suffix(')'))
+    else {
+        return primitive(value);
+    };
+    if let Some((angle, factor)) = inner.split_once('*') {
+        return Some(primitive(angle)? * factor.trim().parse::<f32>().ok()?);
+    }
+    if let Some((angle, divisor)) = inner.split_once('/') {
+        let divisor = divisor.trim().parse::<f32>().ok()?;
+        return (divisor != 0.0).then(|| primitive(angle).map(|angle| angle / divisor)).flatten();
+    }
+    primitive(inner)
+}
+
+fn parse_transform_origin(value: &str) -> Option<(crate::Dimension, crate::Dimension)> {
+    let mut x = None;
+    let mut y = None;
+    for token in value.split_whitespace().take(2) {
+        match token.to_ascii_lowercase().as_str() {
+            "left" => x = Some(crate::Dimension::Percent(0.0)),
+            "right" => x = Some(crate::Dimension::Percent(1.0)),
+            "top" => y = Some(crate::Dimension::Percent(0.0)),
+            "bottom" => y = Some(crate::Dimension::Percent(1.0)),
+            "center" if x.is_none() => x = Some(crate::Dimension::Percent(0.5)),
+            "center" => y = Some(crate::Dimension::Percent(0.5)),
+            _ if x.is_none() => x = Some(dimension_value(token)),
+            _ => y = Some(dimension_value(token)),
+        }
+    }
+    if x.is_none() && y.is_none() {
+        return None;
+    }
+    Some((
+        x.unwrap_or(crate::Dimension::Percent(0.5)),
+        y.unwrap_or(crate::Dimension::Percent(0.5)),
+    ))
+}
+
+fn parse_individual_scale(style: &mut LayoutStyle, value: &str) {
+    if value.trim().eq_ignore_ascii_case("none") {
+        style.transform_scale = None;
+        return;
+    }
+    let values: Vec<f32> = value
+        .split_whitespace()
+        .take(2)
+        .filter_map(scale_number)
+        .collect();
+    let Some(&x) = values.first() else { return };
+    let y = values.get(1).copied().unwrap_or(x);
+    style.transform_scale = Some((x, y));
+    set_containing_block_trigger(style, crate::CB_TRIGGER_TRANSFORM, true);
 }
 
 fn non_none_value(value: &str) -> bool {
@@ -3233,9 +3375,9 @@ fn edges(value: &str) -> Option<Edges> {
 /// Split a 1-or-2 value shorthand into (start, end); a single value applies to
 /// both. Used by the logical-property axes (`margin-inline`, `padding-block`).
 fn two(value: &str) -> (&str, &str) {
-    let mut it = value.split_whitespace();
+    let values = split_ws_paren(value);
-    let a = it.next().unwrap_or("0");
+    let a = values.first().copied().unwrap_or("0");
-    let b = it.next().unwrap_or(a);
+    let b = values.get(1).copied().unwrap_or(a);
     (a, b)
 }
 
@@ -3349,7 +3491,7 @@ fn set_padding_px(padding: &mut Edges, idx: usize, px: f32) {
 
 /// `padding: <t> <r>? <b>? <l>?`, percentage-aware per side.
 fn apply_padding_shorthand(style: &mut LayoutStyle, value: &str) {
-    let toks: Vec<&str> = value.split_whitespace().collect();
+    let toks = split_ws_paren(value);
     let (t, r, b, l) = match toks.as_slice() {
         [a] => (*a, *a, *a, *a),
         [v, h] => (*v, *h, *v, *h),
@@ -3379,7 +3521,7 @@ fn percent_fraction(tok: &str) -> Option<f32> {
 /// `margin: <t> <r>? <b>? <l>?` with per-side `auto` (so `margin: 0 auto`
 /// centers).
 fn apply_margin_shorthand(style: &mut LayoutStyle, value: &str) {
-    let toks: Vec<&str> = value.split_whitespace().collect();
+    let toks = split_ws_paren(value);
     let (t, r, b, l) = match toks.as_slice() {
         [a] => (*a, *a, *a, *a),
         [v, h] => (*v, *h, *v, *h),

crates/obscura-render/tests/layout_test.rs

@@ -1698,6 +1698,40 @@ fn selected_picture_source_dimensions_override_fallback_image_ratio() {
     assert_eq!(narrow.styles[&image].aspect_ratio, Some(1.0));
 }
 
+#[test]
+fn responsive_escaped_utility_classes_apply_logical_padding() {
+    let tree = parse_html(
+        r#"
+        <style>
+          :root { --spacing: .25rem }
+          *, ::before, ::after { box-sizing: border-box }
+          @media (min-width: 40rem) {
+            .sm\:px-2 { padding-inline: calc(var(--spacing) * 2) }
+            .sm\:py-4 { padding-block: calc(var(--spacing) * 4) }
+          }
+        </style>
+        <a id="cell" class="sm:px-2 sm:py-4"
+           style="display:block;width:270px">
+          <span id="child" style="display:block;height:20px"></span>
+        </a>
+        "#,
+    );
+    let cell_id = tree.get_element_by_id("cell").unwrap();
+    assert_eq!(
+        tree.query_selector(r".sm\:px-2").unwrap(),
+        Some(cell_id),
+        "the escaped utility selector must decode to the literal class token"
+    );
+    let layout = layout_dom(&tree, (1280.0, 900.0));
+    let cell = layout.rects[&cell_id];
+    let child = layout.rects[&tree.get_element_by_id("child").unwrap()];
+
+    assert!((cell.width - 270.0).abs() < 0.01, "{cell:?}");
+    assert!((cell.height - 52.0).abs() < 0.01, "{cell:?}");
+    assert!((child.x - cell.x - 8.0).abs() < 0.01, "{child:?}");
+    assert!((child.y - cell.y - 16.0).abs() < 0.01, "{child:?}");
+}
+
 /// HTML width/height attributes are provisional presentational hints. Once
 /// the image is decoded, its natural dimensions replace that mapped ratio.
 #[test]