contain Strictness Levels Lookup
Supported containment keyword expansion; not style encapsulation or assumption that content stays visible outside paint bounds. Explicit supplied computed/layout context only; not a browser cascade/layout engine or cross-browser guarantee.
Description
Containment separates selected effects on layout, painting, sizing and style.
Containment separates selected effects on layout, painting, sizing and style.1
A stored containment label does not establish that it suits an actual component. Use contain Strictness Levels Lookup to look up a supported term.
When to use contain Strictness Levels Lookup
Use contain Strictness Levels Lookup to look up a supported term. Choose the exact supported token from the table; preserve its punctuation and capitalization.
How to use contain Strictness Levels Lookup and understand its results
- Choose the exact supported token from the table; preserve its punctuation and capitalization.
- Enter Contain using the field table and validation rules below, then run the tool.
- Read Meaning and interpret units, signs, ordering and placeholders as explained below.
- If the tool reports an input error, correct that field and rerun. A successful false result, empty match list or unknown-evidence placeholder has the specific meaning described here; check the limitations before applying the result.
| Input field | Meaning | Value type | Requirement |
|---|---|---|---|
| contain | Contain | string | Required; constraints below |
Enter one of the exact supported contain tokens in the table below. The implementation performs a case-sensitive lookup and returns the stored meaning without interpreting a stylesheet, audio recording or performance. Unsupported tokens, added whitespace and alternate capitalization are input errors. The entries describe a bounded vocabulary rather than every valid value in the wider topic.
meaning = storedTable[exactSupportedToken] Field order, units and branch conditions follow the implementation explanation above.
| Exact supported token | Stored meaning |
|---|---|
| none | no containment requested |
| layout | layout containment |
| paint | paint containment |
| size | size containment in both dimensions |
| inline-size | inline-axis size containment |
| style | style containment effects |
| content | layout style paint containment |
| strict | size layout style paint containment |
| Output field | Meaning | Value type |
|---|---|---|
| meaning | Stored explanation for the exact supported token. | string |
{
"input": {
"contain": "strict"
},
"output": {
"meaning": "size layout style paint containment"
}
}Limitations and assumptions
A stored containment label does not establish that it suits an actual component. Apply the exact scope and assumptions described above.
All listed fields require explicit values. Unexpected fields, incorrect types, nonfinite numbers and sparse arrays fail validation. Domain-specific bounds, alignments and supported tokens are stated above; extremely large inputs or outputs can also be rejected. These errors differ from successful results such as false, no matches or unknown evidence.
Alternative or Complementary methods
Use isolation Stacking Context Fix Note for a related task: Isolation can create a stacking context and restrict blending with the outside backdrop.
Use @layer revert-layer Cascade Order Lookup for a related task: Cascade layers have ordering rules that differ for normal and important declarations.
References
-
contain Strictness Levels Lookup — tool.io
Similar or alternative tools
- isolation Stacking Context Fix Note
Isolation can create a stacking context and restrict blending with the outside backdrop.
- @layer revert-layer Cascade Order Lookup
Cascade layers have ordering rules that differ for normal and important declarations.