render: paint generated boxes with contextual backgrounds

crates/obscura-render/src/lib.rs

@@ -251,6 +251,11 @@ pub struct LayoutStyle {
     /// o'clock per CSS, list of (rgba, optional 0..1 stop position)). Modern
     /// hero sections use gradients heavily; without this they paint white.
     pub background_gradient: Option<(f32, Vec<([u8; 4], Option<f32>)>)>,
+    /// First `radial-gradient(...)` layer: center in box-relative fractions
+    /// and color stops. It is painted below the first linear layer, matching
+    /// the common `linear-gradient(...), radial-gradient(...)` hero pattern.
+    pub background_radial_gradient:
+        Option<((f32, f32), Vec<([u8; 4], Option<f32>)>)>,
     /// `conic-gradient(...)` background. The angle is the CSS `from` angle,
     /// the center is a fraction of the border box, and stops are normalized
     /// during paint. Conic gradients commonly provide the color source for a
@@ -265,6 +270,9 @@ pub struct LayoutStyle {
     /// `10px` applies to both axes, matching how small square icons are
     /// almost always sized).
     pub background_size: Option<(f32, f32)>,
+    /// Raw one/two-axis `background-size` expression, retained for paint-time
+    /// resolution against the final owner box (`calc(100% - 2rem) auto`).
+    pub background_size_expression: Option<String>,
     /// Keyword `background-size` behavior. `None` is CSS `auto`, which uses
     /// the image's intrinsic dimensions rather than stretching it to the box.
     pub background_size_fit: Option<ObjectFit>,
@@ -440,6 +448,11 @@ pub struct LayoutStyle {
     /// children, same as if it were real text content.
     pub before_content: Option<String>,
     pub after_content: Option<String>,
+    /// Computed boxes generated by `::before`/`::after`. Text-only pseudos
+    /// continue through `before_content`/`after_content`; these styles retain
+    /// positioned decorative boxes for layout-independent painting.
+    pub before_pseudo: Option<Box<LayoutStyle>>,
+    pub after_pseudo: Option<Box<LayoutStyle>>,
 
     /// True for `inline-block`/`inline-flex`/`inline-grid`: participates in
     /// the surrounding inline flow from the outside, like plain `inline`