CSS Important Suffix Formatter

Description

Replace a top-level important suffix using an explicit flag without duplicating it; restricted comment-free balanced CSS values.

CSS combines token syntax, property-specific value rules and layout/cascade processing. These are separate layers: splitting a declaration does not establish that its value is valid, and arithmetic on resolved lengths does not perform browser layout. Each tool here handles an explicit numeric representation or a stated lexical subset.

Replace a top-level important suffix using an explicit flag without duplicating it; restricted comment-free balanced CSS values.

When to use this tool

Use this tool to replace a top-level important suffix using an explicit flag without duplicating it; restricted comment-free balanced CSS values.

How to use the tool and how it works

Enter value, important using the input definitions below.
Run the operation. Resolve malformed-input errors before interpreting the result.
Read result.value. Interpret signs, units, ordering and null values using the rules below.

Parse and remove an existing recognized terminal importance suffix, then append exactly one space plus !important only when the supplied flag is true.^{[1, 2]}

Input field	Meaning and units	Accepted input
value	CSS-subset value text; quoted strings and grouping follow the stated lexical rules.	Text, at most 8,192 UTF-16 code units; the stated grammar and narrower limits also apply.
important	Whether the formatted value should end with a single !important annotation.	Boolean true or false.

Output field	Interpretation
result	Object containing the fields below.
result.value	Parsed or formatted CSS-subset value string.

json

{
  "input": {
    "value": "red !important",
    "important": false
  },
  "output": {
    "result": {
      "value": "red"
    }
  }
}

Limitations and assumptions

Only the restricted balanced comment-free value dialect is supported; this does not change selector specificity or the surrounding cascade.
Lengths and times must already be resolved to consistent numeric units. Lexical helpers intentionally support smaller grammars than a full browser CSS parser; malformed supported-subset input causes an error.
Every declared top-level input is required and unknown fields are rejected. Ordinary strings are limited to 8,192 UTF-16 code units and lists to 128 entries, with tighter operation-specific bounds where stated. JSON text has bounded nesting and node counts.
Numeric outputs must be finite and within the absolute safe-integer magnitude; exact larger integers use decimal text. Source positions are zero-based UTF-16 offsets and span ends are exclusive unless a different convention is explicitly stated.

Alternative or Complementary methods

Use a full CSS parser or browser style/layout APIs when escape handling, error recovery, computed styles or the full cascade matter. These tools expose focused transformations and audits of supplied data.

References

CSS Syntax Level 3 — W3C
Tool behavior and example: CSS Important Suffix Formatter — tool.io

Similar or alternative tools

CSS Important Suffix Parser
Parse an unquoted top-level terminal important suffix in a balanced restricted CSS value; comments are rejected.
CSS Duplicate Property Table
Audit declaration property duplicates with ordinary ASCII property folding and case-sensitive custom-property names; not a cascade engine.