diff --git a/.changepacks/changepack_log_css_output_edges.json b/.changepacks/changepack_log_css_output_edges.json
new file mode 100644
index 000000000..5d5645a5f
--- /dev/null
+++ b/.changepacks/changepack_log_css_output_edges.json
@@ -0,0 +1,8 @@
+{
+ "changes": {
+ "bindings/devup-ui-wasm/package.json": "Patch",
+ "apps/landing/package.json": "Patch"
+ },
+ "note": "Preserve unitless legacy vendor numbers, classify vendor time values as milliseconds and emit the Opera vendor prefix correctly; reject nested responsive arrays and known dead unprefixed CSS property names with source-located build errors, while preserving supported experimental CSS, unknown properties and documented shorthands.",
+ "date": "2026-10-01T00:00:00.000Z"
+}
diff --git a/apps/landing/src/app/(detail)/docs/api/box/page.mdx b/apps/landing/src/app/(detail)/docs/api/box/page.mdx
index a81f55be1..b5c25c831 100644
--- a/apps/landing/src/app/(detail)/docs/api/box/page.mdx
+++ b/apps/landing/src/app/(detail)/docs/api/box/page.mdx
@@ -64,12 +64,12 @@ However, the following properties are exceptions and **are not multiplied by 4**
- `grid-column`, `grid-column-start`, `grid-column-end`
- `grid-row`, `grid-row-start`, `grid-row-end`
- `animation-iteration-count`
-- `tab-size`, `moz-tab-size`, `-webkit-line-clamp`
+- `tab-size`, `-moz-tab-size`, `-webkit-line-clamp`
- `grid-area`
- `column-count`, `columns`, `orphans`, `widows`, `zoom`
- `border-image`, `border-image-outset`, `border-image-slice`, `border-image-width`
- `mask-border`, `mask-border-outset`, `mask-border-slice`, `mask-border-width`
-- `box-flex`, `box-flex-group`, `box-ordinal-group`, `initial-letter`, `max-lines`, `shape-image-threshold`
+- `initial-letter`, `max-lines`, `shape-image-threshold`
- `fill-opacity`, `flood-opacity`, `stop-opacity`, `stroke-opacity`, `stroke-width`, `stroke-dashoffset`, `stroke-miterlimit`
### Rendering as Another Element
diff --git a/apps/landing/src/app/(detail)/docs/api/button/page.mdx b/apps/landing/src/app/(detail)/docs/api/button/page.mdx
index 1eb82336b..dfe315649 100644
--- a/apps/landing/src/app/(detail)/docs/api/button/page.mdx
+++ b/apps/landing/src/app/(detail)/docs/api/button/page.mdx
@@ -61,10 +61,10 @@ However, the following properties are exceptions and **are not multiplied by 4**
- `grid-column`, `grid-column-start`, `grid-column-end`
- `grid-row`, `grid-row-start`, `grid-row-end`
- `animation-iteration-count`
-- `tab-size`, `moz-tab-size`, `-webkit-line-clamp`
+- `tab-size`, `-moz-tab-size`, `-webkit-line-clamp`
- `grid-area`
- `column-count`, `columns`, `orphans`, `widows`, `zoom`
- `border-image`, `border-image-outset`, `border-image-slice`, `border-image-width`
- `mask-border`, `mask-border-outset`, `mask-border-slice`, `mask-border-width`
-- `box-flex`, `box-flex-group`, `box-ordinal-group`, `initial-letter`, `max-lines`, `shape-image-threshold`
+- `initial-letter`, `max-lines`, `shape-image-threshold`
- `fill-opacity`, `flood-opacity`, `stop-opacity`, `stroke-opacity`, `stroke-width`, `stroke-dashoffset`, `stroke-miterlimit`
diff --git a/apps/landing/src/app/(detail)/docs/api/center/page.mdx b/apps/landing/src/app/(detail)/docs/api/center/page.mdx
index 0ac65ae80..ca80b77bb 100644
--- a/apps/landing/src/app/(detail)/docs/api/center/page.mdx
+++ b/apps/landing/src/app/(detail)/docs/api/center/page.mdx
@@ -84,12 +84,12 @@ However, the following properties are exceptions and **are not multiplied by 4**
- `grid-column`, `grid-column-start`, `grid-column-end`
- `grid-row`, `grid-row-start`, `grid-row-end`
- `animation-iteration-count`
-- `tab-size`, `moz-tab-size`, `-webkit-line-clamp`
+- `tab-size`, `-moz-tab-size`, `-webkit-line-clamp`
- `grid-area`
- `column-count`, `columns`, `orphans`, `widows`, `zoom`
- `border-image`, `border-image-outset`, `border-image-slice`, `border-image-width`
- `mask-border`, `mask-border-outset`, `mask-border-slice`, `mask-border-width`
-- `box-flex`, `box-flex-group`, `box-ordinal-group`, `initial-letter`, `max-lines`, `shape-image-threshold`
+- `initial-letter`, `max-lines`, `shape-image-threshold`
- `fill-opacity`, `flood-opacity`, `stop-opacity`, `stroke-opacity`, `stroke-width`, `stroke-dashoffset`, `stroke-miterlimit`
diff --git a/apps/landing/src/app/(detail)/docs/api/grid/page.mdx b/apps/landing/src/app/(detail)/docs/api/grid/page.mdx
index 01c06c307..4f9a5b446 100644
--- a/apps/landing/src/app/(detail)/docs/api/grid/page.mdx
+++ b/apps/landing/src/app/(detail)/docs/api/grid/page.mdx
@@ -76,12 +76,12 @@ However, the following properties are exceptions and **are not multiplied by 4**
- `grid-column`, `grid-column-start`, `grid-column-end`
- `grid-row`, `grid-row-start`, `grid-row-end`
- `animation-iteration-count`
-- `tab-size`, `moz-tab-size`, `-webkit-line-clamp`
+- `tab-size`, `-moz-tab-size`, `-webkit-line-clamp`
- `grid-area`
- `column-count`, `columns`, `orphans`, `widows`, `zoom`
- `border-image`, `border-image-outset`, `border-image-slice`, `border-image-width`
- `mask-border`, `mask-border-outset`, `mask-border-slice`, `mask-border-width`
-- `box-flex`, `box-flex-group`, `box-ordinal-group`, `initial-letter`, `max-lines`, `shape-image-threshold`
+- `initial-letter`, `max-lines`, `shape-image-threshold`
- `fill-opacity`, `flood-opacity`, `stop-opacity`, `stroke-opacity`, `stroke-width`, `stroke-dashoffset`, `stroke-miterlimit`
diff --git a/apps/landing/src/app/(detail)/docs/api/v-stack/page.mdx b/apps/landing/src/app/(detail)/docs/api/v-stack/page.mdx
index fb7b8b524..63a833815 100644
--- a/apps/landing/src/app/(detail)/docs/api/v-stack/page.mdx
+++ b/apps/landing/src/app/(detail)/docs/api/v-stack/page.mdx
@@ -82,12 +82,12 @@ However, the following properties are exceptions and **are not multiplied by 4**
- `grid-column`, `grid-column-start`, `grid-column-end`
- `grid-row`, `grid-row-start`, `grid-row-end`
- `animation-iteration-count`
-- `tab-size`, `moz-tab-size`, `-webkit-line-clamp`
+- `tab-size`, `-moz-tab-size`, `-webkit-line-clamp`
- `grid-area`
- `column-count`, `columns`, `orphans`, `widows`, `zoom`
- `border-image`, `border-image-outset`, `border-image-slice`, `border-image-width`
- `mask-border`, `mask-border-outset`, `mask-border-slice`, `mask-border-width`
-- `box-flex`, `box-flex-group`, `box-ordinal-group`, `initial-letter`, `max-lines`, `shape-image-threshold`
+- `initial-letter`, `max-lines`, `shape-image-threshold`
- `fill-opacity`, `flood-opacity`, `stop-opacity`, `stroke-opacity`, `stroke-width`, `stroke-dashoffset`, `stroke-miterlimit`
diff --git a/bindings/devup-ui-wasm/src/css_output_edge_tests.rs b/bindings/devup-ui-wasm/src/css_output_edge_tests.rs
new file mode 100644
index 000000000..4d6676352
--- /dev/null
+++ b/bindings/devup-ui-wasm/src/css_output_edge_tests.rs
@@ -0,0 +1,290 @@
+use super::{
+ ImportAlias, Output, code_extract_without_source_map_internal, set_debug, with_style_sheet_mut,
+};
+use css::{class_map::reset_class_map, file_map::reset_file_map};
+use rstest::rstest;
+use serial_test::serial;
+use sheet::StyleSheet;
+use std::collections::BTreeMap;
+use std::collections::HashMap;
+
+fn compile(source: &str) -> Result