@thi.ng/meta-css

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About
Generating CSS frameworks
Converting meta stylesheets to CSS
Exporting a generated framework as CSS
- Media query variations
Development mode
Documenting a generated framework
- Documentation metadata
Bundled CSS base framework
- Classes by category
  - Accessibility
  - Animation / transition
  - Aspect ratios
  - Background
  - Background color
  - Border color
  - Border radius
  - Border width
  - Box sizing
  - Color scheme
  - Content
  - Cursors
  - Display mode
  - Flex layout
  - Font families
  - Font sizes
  - Font style
  - Font variants
  - Font weights
  - Grid layout
  - Height
  - Icons
  - Letter spacing
  - Line heights
  - Lists
  - Margin
  - Mask
  - Max. height
  - Max. width
  - Min. height
  - Min. width
  - Opacity
  - Overflow
  - Padding
  - Positions
  - Print
  - Scrolling
  - Selection
  - Shadow
  - Svg
  - Text align
  - Text color
  - Text decorations
  - Text transforms
  - Vertical align
  - Visibility
  - Whitespace
  - Width
  - Z-indices
- Templates by category
  - Animation / transition
  - Appearance
  - Aspect ratios
  - Background
  - Background color
  - Border color
  - Color adjustment
  - Color definitions
  - Color scheme
  - Dimensions
  - Font families
  - Fx
  - Grid layout
  - Layout
  - Margin
  - Mask
  - Padding
  - Positions
  - Svg
  - Text color
- Media queries
Status
Related packages
Installation
Dependencies
Usage examples
Authors
License

About

Data-driven CSS framework codegen, transpiler & bundler.

This toolkit (started as experiment in 2016) and the overall design approach and workflows proposed by it are heavily building atop the concept of CSS utility classes (as known from Tachyons, Turret or the newer Tailwind projects). How and where those CSS classes are defined and later applied is however a major defining point of difference to these other existing approaches and will be explained in this document. To remove the need for any complex & bloated CSS-related dependencies (parsers etc.) and to simplify building secondary tooling (e.g. part of this readme is an auto-generated report of the included base framework specs), we're using JSON — rather than CSS — as data format to:

express the generative rules to define all the CSS classes, class templates, declarations, and media query criteria, all of which are forming a framework
as intermediate data format for generated CSS frameworks themselves

The entire toolkit (incl. all bundled dependencies) is currently only 36KB (unzipped)!

This readme aims to provide a thorough overview of this toolchain, its possibilities and some concrete usage examples...

Note: In all cases, final CSS generation itself is handled by thi.ng/hiccup-css. Please see its readme for further useful information.

👷🏻 This is all WIP! See included & linked examples for concrete usage...

Generating CSS frameworks

The generate command is used to generate custom CSS frameworks with (likely) hundreds of utility classes, all derived from a number of extremely compact, parametric JSON rule specs. This process generates all desired, combinatorial versions of various rules/declarations and exports them to a framework JSON file used as intermediary stage for the other commands provided by this toolchain. The syntax/format of the generator rules is explained further on. These framework specs can be split up into multiple files for better handling and organization, can define CSS base declarations (e.g. for normalization purposes), arbitrary media query criteria (all later combinable), shared lookup tables for colors, margins, sizes, timings etc.

The package includes dozens of generator specs for a basic, fully customizable, Tachyons-derived CSS framework. These specs and resulting framework are still being worked on and are used for some example projects in this repo, but are mostly intended as basic starting points for creating other custom frameworks (in the hope some useful specs will be shared back similarly)...

metacss generate --help

Usage: metacss generate [opts] inputs...

Flags:

-p, --pretty            Pretty print output
-v, --verbose           Display extra process information

Main:

-o STR, --out STR       Output file (or stdout)
--prec INT              Number of fractional digits (default: 3)

Framework generation specs & syntax

This section gives an overview of the JSON format used to generate CSS frameworks of dozens (usually hundreds or thousands) of utility classes, including many possible variations (per spec).

Generation specs use a simple JSON structure as shown below. The specs can be split over multiple files and will all be merged by the generate command of the toolchain.

{
    // optional meta data (later used for comment injection in generated CSS)
    "info": {
        "name": "Framework name",
        "version": "0.0.0",
    },
    // optional media queries and their criteria, will be merged from multiple spec files
    "media": {
        "large": { "min-width": "60rem" },
        "dark": { "prefers-color-scheme": "dark" },
        "anim": { "prefers-reduced-motion": false }
    },
    // optional shared values/LUTs (arrays or objects)
    // (local to the current file only)
    "tables": {
        "margins": [0, 0.25, 0.5, 1, 2, 4]
    },
    // optional shared variations (local to current file only)
    "vars": {
        "size": ["width", "height"]
    },
    // optional thi.ng/hiccup-css declarations which will be part of the framework
    // (e.g. for CSS reset purposes), will be merged from multiple spec files
    "decls": [
        ["html", { "box-sizing": "border-box" }]
    ],
    // array of class generation specs
    "specs": [
        //...
    ],
    // array of templated class generation specs
    "tpls": [
        //...
    ]
}

Example generation spec

The following generator document uses a single small generative rule spec to create altogether 21 utility classes for various possible margins (where 21 = 3 margin sizes provided × 7 variations).

For each additional value added to the margins table, 7 more CSS classes will be generated. The name (class) and props (CSS property name) are parametric and will be explained in more detail further below.

{
    "tables": {
        "margins": [0, 0.5, 1]
    },
    "specs": [
        {
            "name": "m<vid><k>",
            "props": "margin<var>",
            "values": "margins",
            "unit": "rem",
            "vars": ["a", "t", "r", "b", "l", "h", "v"]
        }
    ]
}

Assuming the above spec has been saved to file margins.mcss.json...

# the generate cmd can merge specs from multiple input files
# if no `--out` file is given, the result will go to stdout
metacss generate --pretty margins.mcss.json

...this command (with the above spec) will generate the following output (here we're only interested in the entries under classes):

{
    "info": {
        "name": "TODO",
        "version": "0.0.0"
    },
    "media": {},
    "classes": {
        "ma0": { "margin": "0rem" },
        "ma1": { "margin": ".5rem" },
        "ma2": { "margin": "1rem" },
        "mh0": { "margin-left": "0rem", "margin-right": "0rem" },
        "mh1": { "margin-left": ".5rem", "margin-right": ".5rem" },
        "mh2": { "margin-left": "1rem", "margin-right": "1rem" },
        "mv0": { "margin-top": "0rem", "margin-bottom": "0rem" },
        "mv1": { "margin-top": ".5rem", "margin-bottom": ".5rem" },
        "mv2": { "margin-top": "1rem", "margin-bottom": "1rem" },
        "mt0": { "margin-top": "0rem" },
        "mt1": { "margin-top": ".5rem" },
        "mt2": { "margin-top": "1rem" },
        "mr0": { "margin-right": "0rem" },
        "mr1": { "margin-right": ".5rem" },
        "mr2": { "margin-right": "1rem" },
        "mb0": { "margin-bottom": "0rem" },
        "mb1": { "margin-bottom": ".5rem" },
        "mb2": { "margin-bottom": "1rem" },
        "ml0": { "margin-left": "0rem" },
        "ml1": { "margin-left": ".5rem" },
        "ml2": { "margin-left": "1rem" }
    }
}

When later used in stylesheets, we can then refer to each of these classes by their generated names, e.g. ma0 to disable all margins or mh2 to set both left & right margins to 1rem (in this case)...

Generator spec structure

An individual generator spec JSON object can contain the following keys:

ID	Type	Description
`doc`	object, optional	Documentation metadata, see section
`key`	string, optional	Method for deriving keys from current value
`name`	string	Parametric name for the generated CSS class(es)
`props`	string or object	CSS property name(s), possibly parametric
`unit`	string, optional	CSS unit to use for values
`user`	any, optional	Custom, arbitrary user data etc.
`values`	string, array or object	Values to be assigned to CSS properties, possibly parametric
`vars`	string[], optional	Array of variation IDs (see section below)

The number of generated CSS classes per spec is the number of items in values multiplied by the number of variations in var (if any).

Any user data will be stored (as is) with each generated CSS class, but currently has no direct use in the toolchain and is purely intended for additional user-defined custom tooling.

Variations

Variations can be requested by providing an array of valid variation IDs. If used, <vid> or <var> parameters must be used in the name or else naming conflicts will occur.

The following variation presets are available:

ID	Expanded values
`""`	`[""]`
`"a"`	`[""]`
`"b"`	`["-bottom"]`
`"bottom"`	`["bottom"]`
`"h"`	`["-left", "-right"]`
`"l"`	`["-left"]`
`"left"`	`["left"]`
`"r"`	`["-right"]`
`"right"`	`["right"]`
`"t"`	`["-top"]`
`"top"`	`["top"]`
`"v"`	`["-top", "-bottom"]`
`"x"`	`["-x"]`
`"y"`	`["-y"]`

Custom, file-local variations can also be used (parameters in name and props will be explained next), e.g.:

{
    "vars": {
        "svg": ["fill", "stroke"]
    },
    "specs": [
        {
            "name": "<var>-<k>",
            "props": { "<var>": "<v>" },
            "values": { "black": "#000", "white": "#fff", "current": "currentColor" },
            "vars": ["svg"]
        }
    ]
}

This spec will generate the following classes:

{
    "fill-black": { "fill": "#000" },
    "fill-white": { "fill": "#fff" },
    "fill-current": { "fill": "currentColor" },
    "stroke-black": { "stroke": "#000" },
    "stroke-white": { "stroke": "#fff" },
    "stroke-current": { "stroke": "currentColor" }
}

Parametric IDs

The following parameters can (and should) be used in a spec's name and props to generate multiple pattern-based values (more examples below).

<vid> is the ID of the currently processed variation (e.g. a value from the ID column in the above table). If no variations are requested, this value will be an empty string.
<var> is one of the expanded values for the current variation (e.g. 2nd column of variations table). If no variations are defined, this too will be an empty string.
<v> is the currently processed value of a spec's values.
<k> is the (possibly derived) key for the currently processed value of a spec's values collection and will depend on the type of values (see key value generation)

Values

The values are used to populate the props (CSS properties). If values is a string it will be used as table-name to look up in the current spec file's tables, an object storing value collections which should be shared among specs (only in the same file).

Other allowed types of values: string array, numeric array or object of key-value pairs (where values are strings or numbers too). The following examples will all produce the same outcome:

Using a named tables entry:

{
    "tables": {
        "test": ["red", "green", "blue"]
    },
    "specs": [
        {
            "name": "test-<v>",
            "props": "color",
            "values": "test"
        }
    ]
}

Using an array directly (here only showing the spec itself for brevity):

{
    "name": "test-<v>",
    "props": "color",
    "values": ["red", "green", "blue"]
}

Using an object (ignoring the keys, only using the values here):

{
    "name": "test-<v>",
    "props": "color",
    "values": { "r": "red", "g": "green", "b": "blue"}
}

All 3 versions will result in these utility classes:

{
    "test-red": { "color": "red" },
    "test-green": { "color": "green" },
    "test-blue": { "color": "blue" }
}

Properties

The props field is used to define one or more CSS property names and optionally their intended values (both can be parametric). If props is a string, the values assigned to the property will be those given in values (optionally with assigned unit, if provided)

{
    "name": "bg<k>",
    "props": {
        "background-image": "url(<v>)",
        "background-size": "cover",
    },
    "values": ["abc.jpg", "def.jpg", "xyz.jpg"]
}

Will result in these definitions:

{
    "bg0": { "background-image": "url(abc.jpg)", "background-size": "cover" },
    "bg1": { "background-image": "url(def.jpg)", "background-size": "cover" },
    "bg2": { "background-image": "url(xyz.jpg)", "background-size": "cover" }
}

Key value generation

The key field is only used when values is resolving to an array. In this case this field determines how a "key" value (aka the <k> param for string interpolation) will be derived for each value in values:

`key`	`values`	Description	Examples
`v`	`[10, 20, ...]`	Actual array item value	10, 20, ...
`i`	`[10, 20, ...]`	Array item index	0, 1,...
`i+1`	`[10, 20, ...]`	Array item index + 1	1, 2,...

If values resolves to an object, the <k> param will always be the key of the currently processed value.

{
    "name": "test-<k>",
    "props": "test-prop",
    "values": { "abc": 23, "xyz": 42 }
}

The above spec will generate the following (some parts omitted):

{
    "test-abc": { "test-prop": 23 },
    "test-xyz": { "test-prop": 42 },
}

Templated class definitions

As a special case of "normal" generator specs described above, the toolchain also supports the generation of so-called templated classes, which are very much like callable functions and will later accept zero or more arguments when used in a MetaCSS stylesheet.

These template specs are almost identical to the normal spec format, with the exception of not using the key and values fields, since values will only be provided by the user at a later stage, via template arguments.

A simple generator spec for a templated animation, including keyframe definitions and documentation metadata:

{
    "decls": [
        ["@keyframes" ,"shrink", { "height": "var(--shrink-size)" }, { "height": 0 }]
    ],
    "tpls": [
        {
            "name": "shrink",
            "props": {
                "--shrink-size": "{0}",
                "animation": "shrink {1}s ease-out forward"
            },
            "doc": {
                "group": "animation",
                "desc": "Animation which shrinks the height from given value down to zero",
                "args": [
                    "height: initial height (incl. units)",
                    "duration: in seconds"
                ]
            }
        }
    ]
}

In a MetaCSS stylesheet, the template can then be used like a function call, like so:

shrink(4rem, 1)

Here, two arguments are supplied as comma-separated list between the (..) parens. In the template definition the {0}/{1} patterns are indicating where these numbered args will be inserted. Templates support any number of params/arguments and each one can be used multiple times in multiple locations, incl. property names, values, and in documentation (group, desc and args fields).

Template arguments

When templates are compiled, the number of expected args is computed automatically and later checked against the actually given args when the template is used. An error will be thrown if the given number of args differs.

Any commas inside an argument must be escaped using \,, e.g.

// wrong (the comma inside `repeat()` MUST be escaped...)
#test { grid grid-cols(repeat(3, 1fr), 16rem) }

// correct
#test { grid grid-cols(repeat(3\, 1fr), 16rem) }

If a template's props is a string, the optional unit field can be used to auto-assign a CSS unit to provided args. If props is an object, the unit option will be ignored.

Using the example template defined above, the MetaCSS stylesheet #test { shrink(4rem, 0.5) } will then be expanded to:

#test {
    --shrink-size: 4rem;
    animation: shrink 0.5s ease-out forward;
}

Media query definitions

Media queries can be defined via the top-level media object in a spec file. Each query has an ID and an object of one or more query criteria.

The key-value pairs of the conditional object are interpreted as follows and ALWAYS combined using and:

Key/Value pair	Result
`"min-width": "10rem"`	`(min-width: 10rem)`
`"prefers-color-scheme": "dark"`	`(prefers-color-scheme: dark)`
`print: true`	`print`
`print: false`	`not print`
`print: "only"`	`only print`

See media queries in the bundled base specs

Custom declarations

Each of the JSON spec files can provide fixed CSS declarations via the decls key. These declarations are to be given in thi.ng/hiccup-css format and are passed as is to the CSS serializer used by the convert and export commands. Please see /specs/normalize.mcss.json for examples and the thi.ng/hiccup-css readme for detailed reference.

{
    "decls": [
        [":root", { "font-size": "16px" }],
        ["*", { "margin": 0 }]
    ]
}

Converting meta stylesheets to CSS

The convert command is used to compile & bundle actual CSS from user-provided MetaCSS stylesheets (.mcss files) and the JSON framework specs created by the generate command. The meta-stylesheets support any CSS selectors, are nestable and compose full CSS declarations from lists of the utility classes in the generated framework.

Each item (aka utility class name) can be prefixed with an arbitrary number of media query IDs (also custom defined in the framework): e.g. dark:bg-color-black might refer to a CSS class to set a black ground, with the dark: prefix referring to a defined media query which only applies this class when dark mode is enabled...

Selectors, declarations and media query criteria will be deduplicated and merged from multiple input files. The resulting CSS will only contain referenced rules and can be generated in minified or pretty printed formats (it's also possible to force include CSS classes which are otherwise unreferenced). Additionally, multiple .mcss stylesheets can be watched for changes (their definitions getting merged), and existing CSS files can be included (prepended) in the output(s) too.

metacss convert --help

Usage: metacss convert [opts] input [...]

Flags:

-b, --bundle            Bundle inputs (see `out` option)
-d, --no-decls          Don't emit framework decls
--no-header             Don't emit generated header comment
--no-write              Don't write files, use stdout only
-p, --pretty            Pretty print output
-v, --verbose           Display extra process information
-w, --watch             Watch input files for changes

Main:

-e STR, --eval STR      eval meta stylesheet in given string (ignores other
                        inputs & includes)
-f STR, --force STR     [multiple] CSS classes to force include (wildcards are
                        supported, @-prefix will read from file)
-I STR, --include STR   [multiple] Include CSS files (prepend)
-o STR, --out STR       Output file (or stdout)
--scope STR             Suffix for CSS class names
-s STR, --specs STR     [required] Path to generated JSON defs

Notes:

The --no-write flag is only used if --bundle is disabled
The --out file arg is only used if --bundle is enabled
The --scope option can be used to specify a suffix for all CSS classes.

If bundling is disabled (default), each input .mcss file is converted individually and results are written to the same directory, but using .css as file extension (and unless --no-write is enabled). This behavior is intended for local style definitions of web components.

Meta-stylesheets syntax

As mentioned earlier, the convert command transpiles meta-stylesheets into actual CSS. These stylesheets support any CSS selector, support selector nesting and have the following basic syntax:

// line comment
selector {
  class-id1 class-id2 ...
  {
    nested-selector {
      class-id3 ...
      {
        ...
      }
    }
  }
}

Class identifiers & media query prefixes

As indicated by the above file structure, .mcss stylesheets purely consist of CSS selectors and the names of the utility classes defined in a generated framework. For example, using the bundled framework specs, this simple meta-stylesheet body { ma0 monospace blue } creates a CSS rule for body with the definitions of the generated ma0, monospace and blue classes inline-expanded:

body {
    margin: 0rem;
    font-family: Monaco, Menlo, Consolas, 'Courier New', monospace;
    color: #357edd;
}

Media query prefixes

This toolchain doesn't pre-generate media-query-specific versions of any CSS class, and any utility class ID/token can be prefixed with any number of media query IDs (separated by :). These media queries are defined as part of the framework generation specs and when used as a prefix, multiple query IDs can be combined freely. For example, the meta-stylesheet a:hover { dark:bg-color-blue dark:anim:bg-anim2 } will auto-create two separate CSS @media-query blocks for the query IDs dark and (dark AND anim):

@media (prefers-color-scheme: dark) {
    a:hover {
        background-color: #357edd;
    }
}

@media (prefers-color-scheme: dark) and (not (prefers-reduced-motion)) {
    a:hover {
        transition: 0.25s background-color ease-in-out;
    }
}

A more detailed example, split over two files (for merging & bundling):

readme.mcss:

body {
    // no margins
    ma0
    // default colors
    bg-color-white color-black
    // colors for dark mode
    dark:bg-color-black dark:color-white
}

#app { ma3 }

.bt-group-v > a {
    db w-100 l:w-50 ph3 pv2 bwb1
    dark:bg-color-purple dark:color-white dark:b--color-black
    light:bg-color-light-blue light:color-black light:b--color-white

    // nested selectors
    {
        :hover { bg-color-gold color-black anim:bg-anim2 }
        :first-child { brt3 }
        :last-child { brb3 bwb0 }
    }
}

readme2.mcss:

We will merge the definitions in this file with the ones above (i.e. adding & overriding some of the declarations, here: a larger border radius):

#app { pa2 }

.bt-group-v > a {
    {
        // override border radii
        :first-child { brt4 }
        :last-child { brb4 }
    }
}

# if no --out dir is specified, writes result to stdout...
# use previously generated framework for resolving all identifiers & media queries
metacss convert --pretty --specs framework.json readme.mcss readme2.mcss

Resulting merged CSS bundle output:

/*! MetaCSS base v0.0.1 - generated by thi.ng/meta-css @ 2023-12-18T12:22:36.548Z */
body {
    margin: 0rem;
    background-color: #fff;
    color: #000;
}

#app {
    margin: 1rem;
    padding: .5rem;
}

.bt-group-v > a {
    display: block;
    width: 100%;
    padding-left: 1rem;
    padding-right: 1rem;
    padding-top: .5rem;
    padding-bottom: .5rem;
    border-bottom-style: solid;
    border-bottom-width: .125rem;
}

.bt-group-v > a:hover {
    background-color: #ffb700;
    color: #000;
}

.bt-group-v > a:first-child {
    border-top-left-radius: 1rem;
    border-top-right-radius: 1rem;
}

.bt-group-v > a:last-child {
    border-bottom-left-radius: 1rem;
    border-bottom-right-radius: 1rem;
    border-bottom-style: solid;
    border-bottom-width: 0rem;
}

@media (prefers-color-scheme:dark) {

    body {
        background-color: #000;
        color: #fff;
    }

    .bt-group-v > a {
        background-color: #5e2ca5;
        color: #fff;
        border-color: #000;
    }

}

@media (min-width:60rem) {

    .bt-group-v > a {
        width: 50%;
    }

}

@media (prefers-color-scheme:light) {

    .bt-group-v > a {
        background-color: #96ccff;
        color: #000;
        border-color: #fff;
    }

}

@media not (prefers-reduced-motion) {

    .bt-group-v > a:hover {
        transition: 0.2s background-color ease-in-out;
    }

}

Including custom CSS files

One or more existing CSS files can be included & prepended to the output via the --include/-I arg (which can be given multiple times). These files are used verbatim and will not be transformed or reformatted in any way.

Force inclusion of unreferenced classes

Only the CSS classes (and their optionally associated media queries) referenced in a .mcss stylesheet will appear in the export CSS bundle. This ensures that the resulting CSS will only contain what's actually used (same effect as tree-shaking, only vastly more efficient). However, this also means any CSS classes (and optionally, their media query qualifiers) which are otherwise referenced (e.g. from JS/TS source code or HTML docs) will not be included by default and they will need to be listed manually for forced inclusion.

This can be achieved via the --force/-f arg (also can be given multiple times). This option also supports basic *-wildcard patterns, e.g. bg-* to include all classes with prefix bg-. Furthermore, for larger projects it's useful to store these names/patterns in a separate file. For that purpose, use the @ prefix (e.g. -f @includes.txt) to indicate reading from file (only reading from a single file is supported at current)... See the meta-css-basics example project for concrete usage...

Exporting a generated framework as CSS

The export command is intended for those who're mainly interested in the CSS framework generation aspects of this toolchain. This command merely takes an existing generated framework JSON file and serializes it to a single CSS file, e.g. to be then used with other CSS tooling (e.g. postcss).

As with the convert command, additional CSS files can also be included (prepended) in the output file.

If the --only-decls option is used, only the framework declarations but none of the generated utility classes will be exported.

The --scope option can be used to specify a suffix for all CSS classes.

metacss export --help

Usage: metacss export [opts] input

Flags:

-d, --no-decls          Don't emit framework decls
--no-header             Don't emit generated header comment
--only-decls            Only emit framework decls
-p, --pretty            Pretty print output
-v, --verbose           Display extra process information

Main:

-I STR, --include STR   [multiple] Include CSS files (prepend)
-m ID, --media ID       [multiple] Media query IDs (use 'ALL' for all)
-o STR, --out STR       Output file (or stdout)
--scope STR             Suffix for CSS class names

Media query variations

Users can choose to generate variations of all defined utility classes for any of the framework-defined media query IDs. This will create additional suffixed versions of all classes (with their appropriate media query wrappers) and cause a potentially massive output (depending on the overall number/complexity of the generated classes). Again, the idea is that the resulting CSS file will be post-processed with 3rd party CSS tooling...

For example, if the framework contains a CSS class w-50 (e.g. to set the width to 50%) and media queries for different screen sizes (e.g. named ns, l), then the export with said media queries will also generate classes w-50-ns and w-50-l (incl. their corresponding @media wrappers).

Development mode

The develop command is a combination of the generate and convert commands. It creates file watchers for all input files (both for generator specs and MCSS stylesheets) and then auto-generates/compiles/updates results. Together with Vite this command enables a seamless hot-reloading workflow. Using a multi-process runner like mprocs further simplifies this.

For example, using one of the bundled example projects in this repo (more examples):

cd examples/meta-css-basics

# launch both metacss in dev mode and vite's dev server
mprocs 'yarn css:watch' 'yarn start:only'

See that example's package.json for concrete usage/reference.

metacss develop --help

Usage: metacss develop [opts] input [...]

Flags:

-b, --bundle            Bundle inputs (see `out` option)
-d, --no-decls          Don't emit framework decls
--no-header             Don't emit generated header comment
-p, --pretty            Pretty print output
-v, --verbose           Display extra process information
-w, --watch             Watch input files for changes

Main:

-e STR, --eval STR      eval meta stylesheet in given string (ignores other
                        inputs & includes)
-f STR, --force STR     [multiple] CSS classes to force include (wildcards are
                        supported, @-prefix will read from file)
-I STR, --include STR   [multiple] Include CSS files (prepend)
--out-css STR           [required] Output file for CSS bundle
--out-specs STR         [required] Output file for framework
--prec INT              Number of fractional digits (default: 3)
--scope STR             Suffix for CSS class names

Documenting a generated framework

Generator specs and templates can include documentation metadata, which can then be utilized to produce Markdown documentation via the metacss doc command:

metacss doc --help

Usage: metacss doc [opts] input [...]

Flags:

-v, --verbose           Display extra process information

Main:

-l INT, --level INT     Initial heading level (default: 1)
-o STR, --out STR       Output file (or stdout)
-t STR, --title STR     Main title, set to 'none' to disable (default: "meta")

The command allows for customization of the initial heading level and title.

Documentation metadata

All generator specs and templates can include a doc object with this structure:

"doc": {
    "group": "Section name for the group this spec belongs to",
    "desc": "Description of this spec/class/template",
    "args": [
        "argName1: description",
        "argName2: description...",
    ]
}

Note: The args field is only used for documenting templates.

All values in this doc object can contain parameters which will be interpolated when the framework specs are expanded (via the generate command). For example, the following spec:

{
    "doc": { "group": "box sizing", "desc": "<v>" },
    "name": "<v>",
    "props": "box-sizing",
    "values": ["border-box", "content-box"]
}

...will be expanded to produce these CSS classes:

{
    "border-box": {
        "__doc": { "group": "box sizing", "desc": "border-box" },
        "box-sizing": "border-box"
    },
    "content-box": {
        "__doc": { "group": "box sizing", "desc": "content-box" },
        "box-sizing": "content-box"
    }
}

The command is also used to produce the following documentation of the included base framework specs.

Bundled CSS base framework

The package includes a large number of useful generator specs in /specs. These are readily usable (and used by a growing number of example projects in this repo), but also are provided as starting point to define your own custom framework(s)...

Currently, there are 946 CSS utility classes (incl. 70 templates) defined in "MetaCSS base" (v0.12.0):

Classes by category

Accessibility

screen-reader
screen-reader-focus

Animation / transition

22 items:

anim-alternate (direction)
anim-alternate-reverse (direction)
anim-ease (timing function)
anim-ease-in (timing function)
anim-ease-in-out (timing function)
anim-ease-out (timing function)
anim-linear (timing function)
anim-normal (direction)
anim-pause
anim-play
anim-reverse (direction)
transition-all (all)
transition-bg (background-color)
transition-color (color)
transition-ease (timing function)
transition-ease-in (timing function)
transition-ease-in-out (timing function)
transition-ease-out (timing function)
transition-height (height)
transition-linear (timing function)
transition-none (none)
transition-width (width)

Aspect ratios

bg-aspect-ratio-object (To be used on the element forming the background of a bg-aspect-ratio() parent/wrapper)

Background

17 items:

bg-contain
bg-cover
bg-pos-center (center)
bg-pos-e (right)
bg-pos-n (top)
bg-pos-ne (top right)
bg-pos-nw (top left)
bg-pos-s (bottom)
bg-pos-se (bottom right)
bg-pos-sw (bottom left)
bg-pos-w (left)
bg-repeat (repeat)
bg-repeat-none (no-repeat)
bg-repeat-round (round)
bg-repeat-space (space)
bg-repeat-x (repeat-x)
bg-repeat-y (repeat-y)

Background color

38 items:

bg-color-black (#000)
bg-color-blue (#357edd)
bg-color-current (currentcolor)
bg-color-dark-blue (#00449e)
bg-color-dark-gray (#333)
bg-color-dark-green (#137752)
bg-color-dark-pink (#d5008f)
bg-color-dark-red (#e7040f)
bg-color-gold (#ffb700)
bg-color-gray (#777)
bg-color-green (#19a974)
bg-color-hot-pink (#ff41b4)
bg-color-light-blue (#96ccff)
bg-color-light-gray (#eee)
bg-color-light-green (#9eebcf)
bg-color-light-pink (#ffa3d7)
bg-color-light-purple (#a463f2)
bg-color-light-red (#ff725c)
bg-color-light-silver (#aaa)
bg-color-light-yellow (#fbf1a9)
bg-color-lightest-blue (#cdecff)
bg-color-mid-gray (#555)
bg-color-moon-gray (#ccc)
bg-color-navy (#001b44)
bg-color-near-black (#111)
bg-color-near-white (#f4f4f4)
bg-color-orange (#ff6300)
bg-color-pink (#ff80cc)
bg-color-purple (#5e2ca5)
bg-color-red (#ff4136)
bg-color-silver (#999)
bg-color-transparent (transparent)
bg-color-washed-blue (#f6fffe)
bg-color-washed-green (#e8fdf5)
bg-color-washed-red (#ffdfdf)
bg-color-washed-yellow (#fffceb)
bg-color-white (#fff)
bg-color-yellow (#ffd700)

Border color

38 items:

border-color-black (#000)
border-color-blue (#357edd)
border-color-current (currentcolor)
border-color-dark-blue (#00449e)
border-color-dark-gray (#333)
border-color-dark-green (#137752)
border-color-dark-pink (#d5008f)
border-color-dark-red (#e7040f)
border-color-gold (#ffb700)
border-color-gray (#777)
border-color-green (#19a974)
border-color-hot-pink (#ff41b4)
border-color-light-blue (#96ccff)
border-color-light-gray (#eee)
border-color-light-green (#9eebcf)
border-color-light-pink (#ffa3d7)
border-color-light-purple (#a463f2)
border-color-light-red (#ff725c)
border-color-light-silver (#aaa)
border-color-light-yellow (#fbf1a9)
border-color-lightest-blue (#cdecff)
border-color-mid-gray (#555)
border-color-moon-gray (#ccc)
border-color-navy (#001b44)
border-color-near-black (#111)
border-color-near-white (#f4f4f4)
border-color-orange (#ff6300)
border-color-pink (#ff80cc)
border-color-purple (#5e2ca5)
border-color-red (#ff4136)
border-color-silver (#999)
border-color-transparent (transparent)
border-color-washed-blue (#f6fffe)
border-color-washed-green (#e8fdf5)
border-color-washed-red (#ffdfdf)
border-color-washed-yellow (#fffceb)
border-color-white (#fff)
border-color-yellow (#ffd700)

Border radius

27 items:

br0 (0rem)
br1 (.125rem)
br2 (.25rem)
br3 (.5rem)
br4 (1rem)
br-100 (100%)
br-pill (9999px)
brb0 (bottom 0rem)
brb1 (bottom .125rem)
brb2 (bottom .25rem)
brb3 (bottom .5rem)
brb4 (bottom 1rem)
brl0 (left 0rem)
brl1 (left .125rem)
brl2 (left .25rem)
brl3 (left .5rem)
brl4 (left 1rem)
brr0 (right 0rem)
brr1 (right .125rem)
brr2 (right .25rem)
brr3 (right .5rem)
brr4 (right 1rem)
brt0 (top 0rem)
brt1 (top .125rem)
brt2 (top .25rem)
brt3 (top .5rem)
brt4 (top 1rem)

Border width

35 items:

bw0 ( 0rem)
bw1 ( .125rem)
bw2 ( .25rem)
bw3 ( .5rem)
bw4 ( 1rem)
bw5 ( 2rem)
bw-1px ( 1px)
bwb0 (bottom 0rem)
bwb1 (bottom .125rem)
bwb2 (bottom .25rem)
bwb3 (bottom .5rem)
bwb4 (bottom 1rem)
bwb5 (bottom 2rem)
bwb-1px (bottom 1px)
bwl0 (left 0rem)
bwl1 (left .125rem)
bwl2 (left .25rem)
bwl3 (left .5rem)
bwl4 (left 1rem)
bwl5 (left 2rem)
bwl-1px (left 1px)
bwr0 (right 0rem)
bwr1 (right .125rem)
bwr2 (right .25rem)
bwr3 (right .5rem)
bwr4 (right 1rem)
bwr5 (right 2rem)
bwr-1px (right 1px)
bwt0 (top 0rem)
bwt1 (top .125rem)
bwt2 (top .25rem)
bwt3 (top .5rem)
bwt4 (top 1rem)
bwt5 (top 2rem)
bwt-1px (top 1px)

Box sizing

border-box (border-box)
content-box (content-box)

Color scheme

color-scheme-dark (dark)
color-scheme-light (light)
color-scheme-light-dark (light dark)

Content

6 items:

content-data-lang (data-lang attrib)
content-href (href attrib)
content-id (id attrib)
content-name (name attrib)
content-slot (slot attrib)
content-title (title attrib)

Cursors

36 items:

cursor-alias
cursor-auto
cursor-cell
cursor-col
cursor-context
cursor-copy
cursor-cross
cursor-default
cursor-e
cursor-ew
cursor-forbidden
cursor-grab
cursor-grabbing
cursor-help
cursor-in
cursor-move
cursor-n
cursor-ne
cursor-news
cursor-no-drop
cursor-none
cursor-ns
cursor-nw
cursor-nwse
cursor-out
cursor-pointer
cursor-progress
cursor-row
cursor-s
cursor-scroll
cursor-se
cursor-sw
cursor-text
cursor-vtext
cursor-w
cursor-wait

Display mode

11 items:

db (block)
di (inline)
dib (inline-block)
dif (inline-flex)
dig (inline-grid)
dn (none)
dt (table)
dtc (table-cell)
dtr (table-row)
flex (flex)
grid (grid)

Flex layout

25 items:

align-content-center
align-content-end
align-content-space-around
align-content-space-between
align-content-space-evenly
align-content-start
align-content-stretch
flex-column
flex-column-reverse
flex-grow0
flex-grow1
flex-nowrap
flex-row
flex-row-reverse
flex-shrink0
flex-shrink1
flex-wrap
flex-wrap-reverse
justify-content-center
justify-content-end
justify-content-space-around
justify-content-space-between
justify-content-space-evenly
justify-content-start
justify-content-stretch

Font families

6 items:

monospace
sans-serif
serif
system
system-sans-serif
system-serif

Font sizes

9 items:

f-subtitle (5rem)
f-title (6rem)
f1 (3rem)
f2 (2.25rem)
f3 (1.5rem)
f4 (1.25rem)
f5 (1rem)
f6 (.875rem)
f7 (.75rem)

Font style

italic

Font variants

small-caps

Font weights

11 items:

b (700)
fw100
fw200
fw300
fw400
fw500
fw600
fw700
fw800
fw900
normal (400)

Grid layout

46 items:

align-items-center
align-items-end
align-items-start
align-items-stretch
align-self-center
align-self-end
align-self-start
align-self-stretch
gap0 (0rem)
gap1 (.125rem)
gap2 (.25rem)
gap3 (.5rem)
gap4 (1rem)
gap5 (2rem)
gap-1px
gap-2px
gap-4px
gap-8px
grid-cols-1 (1fr)
grid-cols-2 (1fr 1fr)
grid-cols-3 (1fr 1fr 1fr)
grid-cols-4 (repeat(4,1fr))
grid-cols-5 (repeat(5,1fr))
grid-cols-6 (repeat(6,1fr))
grid-cols-7 (repeat(7,1fr))
grid-cols-8 (repeat(8,1fr))
grid-cols-9 (repeat(9,1fr))
grid-cols-10 (repeat(10,1fr))
grid-rows-1 (1fr)
grid-rows-2 (1fr 1fr)
grid-rows-3 (1fr 1fr 1fr)
grid-rows-4 (repeat(4,1fr))
grid-rows-5 (repeat(5,1fr))
grid-rows-6 (repeat(6,1fr))
grid-rows-7 (repeat(7,1fr))
grid-rows-8 (repeat(8,1fr))
grid-rows-9 (repeat(9,1fr))
grid-rows-10 (repeat(10,1fr))
justify-items-center
justify-items-end
justify-items-start
justify-items-stretch
justify-self-center
justify-self-end
justify-self-start
justify-self-stretch

Height

29 items:

h1 (1rem)
h2 (2rem)
h3 (4rem)
h4 (8rem)
h5 (16rem)
h-10 (%)
h-16 (%)
h-17 (%)
h-20 (%)
h-25 (%)
h-30 (%)
h-33 (%)
h-34 (%)
h-40 (%)
h-50 (%)
h-60 (%)
h-66 (%)
h-67 (%)
h-70 (%)
h-75 (%)
h-80 (%)
h-83 (%)
h-84 (%)
h-90 (%)
h-100 (%)
vh-25
vh-50
vh-75
vh-100

Icons

9 items:

icon-1 (3rem)
icon-2 (2.25rem)
icon-3 (1.5rem)
icon-4 (1.25rem)
icon-5 (1rem)
icon-6 (.875rem)
icon-7 (.75rem)
icon-subtitle (5rem)
icon-title (6rem)

Letter spacing

6 items:

ls-0 (0em)
ls-1 (.05em)
ls-2 (.1em)
ls-3 (.2em)
ls--1 (-.025em)
ls--2 (-.05em)

Line heights

5 items:

lh-0 (0)
lh-copy (1.5)
lh-double (2)
lh-solid (1)
lh-title (1.25)

Lists

list

Margin

55 items:

center
ma0 ( 0rem)
ma1 ( .25rem)
ma2 ( .5rem)
ma3 ( 1rem)
ma4 ( 2rem)
ma5 ( 4rem)
mb0 (bottom 0rem)
mb1 (bottom .25rem)
mb2 (bottom .5rem)
mb3 (bottom 1rem)
mb4 (bottom 2rem)
mb5 (bottom 4rem)
mbe-0 (block end 0rem)
mbe-1 (block end .25rem)
mbe-2 (block end .5rem)
mbe-3 (block end 1rem)
mbe-4 (block end 2rem)
mbe-5 (block end 4rem)
mbs-0 (block start 0rem)
mbs-1 (block start .25rem)
mbs-2 (block start .5rem)
mbs-3 (block start 1rem)
mbs-4 (block start 2rem)
mbs-5 (block start 4rem)
mh0 (left 0rem)
mh1 (left .25rem)
mh2 (left .5rem)
mh3 (left 1rem)
mh4 (left 2rem)
mh5 (left 4rem)
ml0 (left 0rem)
ml1 (left .25rem)
ml2 (left .5rem)
ml3 (left 1rem)
ml4 (left 2rem)
ml5 (left 4rem)
mr0 (right 0rem)
mr1 (right .25rem)
mr2 (right .5rem)
mr3 (right 1rem)
mr4 (right 2rem)
mr5 (right 4rem)
mt0 (top 0rem)
mt1 (top .25rem)
mt2 (top .5rem)
mt3 (top 1rem)
mt4 (top 2rem)
mt5 (top 4rem)
mv0 (top 0rem)
mv1 (top .25rem)
mv2 (top .5rem)
mv3 (top 1rem)
mv4 (top 2rem)
mv5 (top 4rem)

Mask

13 items:

mask-clip-border (border-box)
mask-clip-content (content-box)
mask-clip-fill (fill-box)
mask-clip-none (no-clip)
mask-clip-padding (padding-box)
mask-clip-stroke (stroke-box)
mask-clip-view (view-box)
mask-mode-alpha (alpha)
mask-mode-luminance (luminance)
mask-mode-match-source (match-source)
mask-type-alpha (alpha)
mask-type-luminance (luminance)
mask-type-match-source (match-source)

Max. height

25 items:

maxh1 (1rem)
maxh2 (2rem)
maxh3 (4rem)
maxh4 (8rem)
maxh5 (16rem)
maxh-10 (%)
maxh-16 (%)
maxh-17 (%)
maxh-20 (%)
maxh-25 (%)
maxh-30 (%)
maxh-33 (%)
maxh-34 (%)
maxh-40 (%)
maxh-50 (%)
maxh-60 (%)
maxh-66 (%)
maxh-67 (%)
maxh-70 (%)
maxh-75 (%)
maxh-80 (%)
maxh-83 (%)
maxh-84 (%)
maxh-90 (%)
maxh-100 (%)

Max. width

25 items:

maxw1 (1rem)
maxw2 (2rem)
maxw3 (4rem)
maxw4 (8rem)
maxw5 (16rem)
maxw-10 (%)
maxw-16 (%)
maxw-17 (%)
maxw-20 (%)
maxw-25 (%)
maxw-30 (%)
maxw-33 (%)
maxw-34 (%)
maxw-40 (%)
maxw-50 (%)
maxw-60 (%)
maxw-66 (%)
maxw-67 (%)
maxw-70 (%)
maxw-75 (%)
maxw-80 (%)
maxw-83 (%)
maxw-84 (%)
maxw-90 (%)
maxw-100 (%)

Min. height

25 items:

minh1 (1rem)
minh2 (2rem)
minh3 (4rem)
minh4 (8rem)
minh5 (16rem)
minh-10 (%)
minh-16 (%)
minh-17 (%)
minh-20 (%)
minh-25 (%)
minh-30 (%)
minh-33 (%)
minh-34 (%)
minh-40 (%)
minh-50 (%)
minh-60 (%)
minh-66 (%)
minh-67 (%)
minh-70 (%)
minh-75 (%)
minh-80 (%)
minh-83 (%)
minh-84 (%)
minh-90 (%)
minh-100 (%)

Min. width

25 items:

minw1 (1rem)
minw2 (2rem)
minw3 (4rem)
minw4 (8rem)
minw5 (16rem)
minw-10 (%)
minw-16 (%)
minw-17 (%)
minw-20 (%)
minw-25 (%)
minw-30 (%)
minw-33 (%)
minw-34 (%)
minw-40 (%)
minw-50 (%)
minw-60 (%)
minw-66 (%)
minw-67 (%)
minw-70 (%)
minw-75 (%)
minw-80 (%)
minw-83 (%)
minw-84 (%)
minw-90 (%)
minw-100 (%)

Opacity

11 items:

o-0 (0)
o-10 (0.1)
o-20 (0.2)
o-30 (0.3)
o-40 (0.4)
o-50 (0.5)
o-60 (0.6)
o-70 (0.7)
o-80 (0.8)
o-90 (0.9)
o-100 (1)

Overflow

12 items:

overflow-auto
overflow-hidden
overflow-scroll
overflow-visible
overflow-x-auto
overflow-x-hidden
overflow-x-scroll
overflow-x-visible
overflow-y-auto
overflow-y-hidden
overflow-y-scroll
overflow-y-visible

Padding

54 items:

pa0 ( 0rem)
pa1 ( .25rem)
pa2 ( .5rem)
pa3 ( 1rem)
pa4 ( 2rem)
pa5 ( 4rem)
pb0 (bottom 0rem)
pb1 (bottom .25rem)
pb2 (bottom .5rem)
pb3 (bottom 1rem)
pb4 (bottom 2rem)
pb5 (bottom 4rem)
pbe-0 (block end 0rem)
pbe-1 (block end .25rem)
pbe-2 (block end .5rem)
pbe-3 (block end 1rem)
pbe-4 (block end 2rem)
pbe-5 (block end 4rem)
pbs-0 (block start 0rem)
pbs-1 (block start .25rem)
pbs-2 (block start .5rem)
pbs-3 (block start 1rem)
pbs-4 (block start 2rem)
pbs-5 (block start 4rem)
ph0 (left 0rem)
ph1 (left .25rem)
ph2 (left .5rem)
ph3 (left 1rem)
ph4 (left 2rem)
ph5 (left 4rem)
pl0 (left 0rem)
pl1 (left .25rem)
pl2 (left .5rem)
pl3 (left 1rem)
pl4 (left 2rem)
pl5 (left 4rem)
pr0 (right 0rem)
pr1 (right .25rem)
pr2 (right .5rem)
pr3 (right 1rem)
pr4 (right 2rem)
pr5 (right 4rem)
pt0 (top 0rem)
pt1 (top .25rem)
pt2 (top .5rem)
pt3 (top 1rem)
pt4 (top 2rem)
pt5 (top 4rem)
pv0 (top 0rem)
pv1 (top .25rem)
pv2 (top .5rem)
pv3 (top 1rem)
pv4 (top 2rem)
pv5 (top 4rem)

Positions

25 items:

absolute
bottom-0 (0rem)
bottom-1 (1rem)
bottom-2 (2rem)
bottom--1 (-1rem)
bottom--2 (-2rem)
fixed
left-0 (0rem)
left-1 (1rem)
left-2 (2rem)
left--1 (-1rem)
left--2 (-2rem)
relative
right-0 (0rem)
right-1 (1rem)
right-2 (2rem)
right--1 (-1rem)
right--2 (-2rem)
static
sticky
top-0 (0rem)
top-1 (1rem)
top-2 (2rem)
top--1 (-1rem)
top--2 (-2rem)

Print

18 items:

break-after-avoid
break-after-avoid-column
break-after-avoid-page
break-after-column
break-after-left
break-after-page
break-after-recto
break-after-right
break-after-verso
break-before-avoid
break-before-avoid-column
break-before-avoid-page
break-before-column
break-before-left
break-before-page
break-before-recto
break-before-right
break-before-verso

Scrolling

8 items:

ss-always (snap stop)
ss-both (snap type)
ss-center (snap align)
ss-end (snap align)
ss-normal (snap stop)
ss-start (snap align)
ss-x (snap type)
ss-y (snap type)

Selection

noselect

Shadow

17 items:

box-shadow-1 (0 0 2px 0px #0003)
box-shadow-2 (0 0 4px #0003)
box-shadow-3 (0 0 4px 1px #0003)
box-shadow-4 (0 0 8px 2px #0003)
box-shadow-i-1 (0 0 2px 0px #0003)
box-shadow-i-2 (0 0 4px #0003)
box-shadow-i-3 (0 0 4px 1px #0003)
box-shadow-i-4 (0 0 8px 2px #0003)
text-shadow-1 (1px 1px 2px #0003)
text-shadow-2 (1px 1px 4px #0003)
text-shadow-3 (1px 1px 8px #0003)
text-shadow-4 (2px 2px 2px #0003)
text-shadow-5 (2px 2px 4px #0003)
text-shadow-6 (2px 2px 8px #0003)
text-shadow-7 (3px 3px 2px #0003)
text-shadow-8 (3px 3px 4px #0003)
text-shadow-9 (3px 3px 8px #0003)

Svg

76 items:

fill-black (#000)
fill-blue (#357edd)
fill-current (currentcolor)
fill-dark-blue (#00449e)
fill-dark-gray (#333)
fill-dark-green (#137752)
fill-dark-pink (#d5008f)
fill-dark-red (#e7040f)
fill-gold (#ffb700)
fill-gray (#777)
fill-green (#19a974)
fill-hot-pink (#ff41b4)
fill-light-blue (#96ccff)
fill-light-gray (#eee)
fill-light-green (#9eebcf)
fill-light-pink (#ffa3d7)
fill-light-purple (#a463f2)
fill-light-red (#ff725c)
fill-light-silver (#aaa)
fill-light-yellow (#fbf1a9)
fill-lightest-blue (#cdecff)
fill-mid-gray (#555)
fill-moon-gray (#ccc)
fill-navy (#001b44)
fill-near-black (#111)
fill-near-white (#f4f4f4)
fill-orange (#ff6300)
fill-pink (#ff80cc)
fill-purple (#5e2ca5)
fill-red (#ff4136)
fill-silver (#999)
fill-transparent (transparent)
fill-washed-blue (#f6fffe)
fill-washed-green (#e8fdf5)
fill-washed-red (#ffdfdf)
fill-washed-yellow (#fffceb)
fill-white (#fff)
fill-yellow (#ffd700)
stroke-black (#000)
stroke-blue (#357edd)
stroke-current (currentcolor)
stroke-dark-blue (#00449e)
stroke-dark-gray (#333)
stroke-dark-green (#137752)
stroke-dark-pink (#d5008f)
stroke-dark-red (#e7040f)
stroke-gold (#ffb700)
stroke-gray (#777)
stroke-green (#19a974)
stroke-hot-pink (#ff41b4)
stroke-light-blue (#96ccff)
stroke-light-gray (#eee)
stroke-light-green (#9eebcf)
stroke-light-pink (#ffa3d7)
stroke-light-purple (#a463f2)
stroke-light-red (#ff725c)
stroke-light-silver (#aaa)
stroke-light-yellow (#fbf1a9)
stroke-lightest-blue (#cdecff)
stroke-mid-gray (#555)
stroke-moon-gray (#ccc)
stroke-navy (#001b44)
stroke-near-black (#111)
stroke-near-white (#f4f4f4)
stroke-orange (#ff6300)
stroke-pink (#ff80cc)
stroke-purple (#5e2ca5)
stroke-red (#ff4136)
stroke-silver (#999)
stroke-transparent (transparent)
stroke-washed-blue (#f6fffe)
stroke-washed-green (#e8fdf5)
stroke-washed-red (#ffdfdf)
stroke-washed-yellow (#fffceb)
stroke-white (#fff)
stroke-yellow (#ffd700)

Text align

4 items:

tc (center)
tj (justify)
tl (left)
tr (right)

Text color

38 items:

color-black (#000)
color-blue (#357edd)
color-current (currentcolor)
color-dark-blue (#00449e)
color-dark-gray (#333)
color-dark-green (#137752)
color-dark-pink (#d5008f)
color-dark-red (#e7040f)
color-gold (#ffb700)
color-gray (#777)
color-green (#19a974)
color-hot-pink (#ff41b4)
color-light-blue (#96ccff)
color-light-gray (#eee)
color-light-green (#9eebcf)
color-light-pink (#ffa3d7)
color-light-purple (#a463f2)
color-light-red (#ff725c)
color-light-silver (#aaa)
color-light-yellow (#fbf1a9)
color-lightest-blue (#cdecff)
color-mid-gray (#555)
color-moon-gray (#ccc)
color-navy (#001b44)
color-near-black (#111)
color-near-white (#f4f4f4)
color-orange (#ff6300)
color-pink (#ff80cc)
color-purple (#5e2ca5)
color-red (#ff4136)
color-silver (#999)
color-transparent (transparent)
color-washed-blue (#f6fffe)
color-washed-green (#e8fdf5)
color-washed-red (#ffdfdf)
color-washed-yellow (#fffceb)
color-white (#fff)
color-yellow (#ffd700)

Text decorations

no-underline
strike
underline

Text transforms

7 items:

ttc (capitalize)
ttfsk (full-size-kana)
ttfw (full-width)
tti (initial)
ttl (lowercase)
ttn (none)
ttu (uppercase)

Vertical align

4 items:

v-base (baseline)
v-btm (bottom)
v-mid (middle)
v-top (top)

Visibility

collapse
hidden
visible

Whitespace

ws-normal
ws-nowrap
ws-pre

Width

29 items:

vw-25
vw-50
vw-75
vw-100
w1 (1rem)
w2 (2rem)
w3 (4rem)
w4 (8rem)
w5 (16rem)
w-10 (%)
w-16 (%)
w-17 (%)
w-20 (%)
w-25 (%)
w-30 (%)
w-33 (%)
w-34 (%)
w-40 (%)
w-50 (%)
w-60 (%)
w-66 (%)
w-67 (%)
w-70 (%)
w-75 (%)
w-80 (%)
w-83 (%)
w-84 (%)
w-90 (%)
w-100 (%)

Z-indices

8 items:

z-0
z-1
z-2
z-3
z-4
z-5
z-999
z-9999

Templates by category

Animation / transition

15 items:

`anim(body)`

body: CSS value/definition

`anim-delay(delay)`

delay: time (in seconds)

`anim-duration(duration)`

duration: time (in seconds)

`anim-iter(iter)`

iter: number of iterations

`anim-steps(num)`

num: number of steps

Sets animation-timing-function to steps(num)

`bg-anim(duration)`

duration: in seconds

Transition to tween background color

`fade-in(duration)`

duration: in seconds

Animation to change opacity

`fade-out(duration)`

duration: in seconds

Animation to change opacity

`shrink(duration, height)`

duration: in seconds
height: initial height (incl. units)

Animation which shrinks the height from given initial value to zero. Target element must NOT have padding (use a wrapper if necessary).

`spin(duration)`

duration: in seconds

Animation which rotates element a full turn, looping indefinitely

`transition(body)`

body: CSS value/definition

`transition-delay(delay)`

delay: time (in seconds)

`transition-duration(duration)`

duration: time (in seconds)

`transition-property(prop)`

prop: CSS value/definition

`transition-steps(num)`

num: number of steps

Sets transition-timing-function to steps(num)

Appearance

`appearance(mode)`

mode: CSS value

Sets appearance (incl. -webkit prefixed version) to given value

Aspect ratios

`aspect-ratio(width, height)`

width: aspect width
height: aspect height

Sets aspect-ratio CSS property

`bg-aspect-ratio(width, height)`

width: aspect width
height: aspect height

Sets aspect ratio of background. Use with bg-aspect-ratio-object on child element.

Background

`bg-image(url)`

url: image URL

`bg-pos(body)`

body: CSS value/definition

`bg-size(body)`

body: CSS value/definition

Background color

`bg-color(name)`

name: variable name (without -- prefix)

Border color

`border-color(name)`

name: variable name (without -- prefix)

Color adjustment

4 items:

`adjust-hsl(prop, name, hue, sat, lum, alpha)`

prop: CSS target property
name: color variable name (without -- prefix)
hue: offset in degrees
sat: factor
lum: factor
alpha: factor

Assigns an adjusted version of a def-hsl()-defined color to given CSS property.

`adjust-lch(prop, name, luma, chroma, hue, alpha)`

prop: CSS target property
name: color variable name (without -- prefix)
luma: factor
chroma: factor
hue: offset in degrees
alpha: factor

Assigns an adjusted version of a def-lch() defined color to given CSS property.

`adjust-oklch(prop, name, luma, chroma, hue, alpha)`

prop: CSS target property
name: color variable name (without -- prefix)
luma: factor
chroma: factor
hue: offset in degrees
alpha: alpha factor

Assigns an adjusted version of a def-oklch() defined color to given CSS property.

`adjust-rgb(prop, name, red, green, blue, alpha)`

prop: CSS target property
name: color variable name (without -- prefix)
red: factor
green: factor
blue: factor
alpha: factor

Assigns an adjusted version of a def-rgb()-defined color to given CSS property.

Color definitions

4 items:

`def-hsl(name, hue, sat, lum, alpha)`

name: variable name (without -- prefix)
hue: in degrees
sat: in percent
lum: in percent
alpha: in [0,1] range

Defines a hsl() color variable with given name and additional derived vars for each channel (e.g. --name-hue). Use adjust-hsl() to create derived versions from this base color.

`def-lch(name, luma, chroma, hue, alpha)`

name: variable name
luma: in percent
chroma: in percent
hue: in degrees
alpha: in [0,1] range

Defines a lch() color variable with given name and additional derived vars for each channel (e.g. --name-hue). Use adjust-lch() to create derived versions from this base color.

`def-oklch(name, luma, chroma, hue, alpha)`

name: variable name
luma: in percent
chroma: in percent
hue: in degrees
alpha: in [0,1] range

Defines a oklch() color variable with given name and additional derived vars for each channel (e.g. --name-hue). Use adjust-oklch() to create derived versions from this base color.

`def-rgb(name, red, green, blue, alpha)`

name: variable name (without -- prefix)
red: [0,255] range
green: [0,255] range
blue: [0,255] range
alpha: in [0,1] range

Defines a rgb() color variable with given name and additional derived vars for each channel (e.g. --name-red). Use adjust-rgb() to create derived versions from this base color.

Color scheme

5 items:

`bg-light-dark(light, dark)`

light: variable name (without -- prefix)
dark: variable name (without -- prefix)

Sets background-color using CSS light-dark() function

`border-light-dark(light, dark)`

light: variable name (without -- prefix)
dark: variable name (without -- prefix)

Sets border-color using CSS light-dark() function

`fill-light-dark(light, dark)`

light: variable name (without -- prefix)
dark: variable name (without -- prefix)

Sets fill color using CSS light-dark() function

`light-dark(light, dark)`

light: variable name (without -- prefix)
dark: variable name (without -- prefix)

Sets color using CSS light-dark() function

`stroke-light-dark(light, dark)`

light: variable name (without -- prefix)
dark: variable name (without -- prefix)

Sets stroke color using CSS light-dark() function

Dimensions

6 items:

`height(height)`

height: incl. units

Sets height to given value

`max-height(height)`

height: incl. units

Sets max-height to given value

`max-width(width)`

width: incl. units

Sets max-width to given value

`min-height(height)`

height: incl. units

Sets min-height to given value

`min-width(width)`

width: incl. units

Sets min-width to given value

`width(width)`

width: incl. units

Sets width to given value

Font families

`font-family(body)`

body: CSS value/definition

Fx

`bg-blur(radius)`

radius: incl. units

`blur(radius)`

radius: incl. units

Grid layout

`grid-cols(cols)`

cols: CSS cols definitions

`grid-rows(rows)`

rows: CSS rows definitions

Layout

`columns(num)`

num: column count

Margin

7 items:

`ma(size)`

size: incl. units

Sets margin to custom size

`mb(size)`

size: incl. units

Sets margin to custom size

`mh(size)`

size: incl. units

Sets margin to custom size

`ml(size)`

size: incl. units

Sets margin to custom size

`mr(size)`

size: incl. units

Sets margin to custom size

`mt(size)`

size: incl. units

Sets margin to custom size

`mv(size)`

size: incl. units

Sets margin to custom size

Mask

`mask-image(body)`

body: definition (e.g. url or gradient)

Padding

7 items:

`pa(size)`

size: incl. units

Sets padding to custom size

`pb(size)`

size: incl. units

Sets padding to custom size

`ph(size)`

size: incl. units

Sets padding to custom size

`pl(size)`

size: incl. units

Sets padding to custom size

`pr(size)`

size: incl. units

Sets padding to custom size

`pt(size)`

size: incl. units

Sets padding to custom size

`pv(size)`

size: incl. units

Sets padding to custom size

Positions

4 items:

`bottom(coordinate)`

coordinate (incl. units)

`left(coordinate)`

coordinate (incl. units)

`right(coordinate)`

coordinate (incl. units)

`top(coordinate)`

coordinate (incl. units)

Svg

`fill(name)`

name: variable name (without -- prefix)

`stroke(name)`

name: variable name (without -- prefix)

Text color

`color(name)`

name: variable name (without -- prefix)

Media queries

ns: {"min-width":"640px"}
m: {"min-width":"768px"}
l: {"min-width":"1024px"}
xl: {"min-width":"1280px"}
2xl: {"min-width":"1536px"}
dark: {"prefers-color-scheme":"dark"}
light: {"prefers-color-scheme":"light"}
anim: {"prefers-reduced-motion":false}
noanim: {"prefers-reduced-motion":true}
contrast: {"forced-colors":true}

Status

ALPHA - bleeding edge / work-in-progress

Search or submit any issues for this package

Related packages

@thi.ng/hiccup-css - CSS from nested JS data structures

Installation

npx @thi.ng/meta-css --help

Bun is required instead of Node JS. The toolchain itself is distributed as CLI bundle with no runtime dependencies. The following dependencies are only shown for informational purposes and are (partially) included in the bundle.

Package sizes (brotli'd, pre-treeshake): ESM: 13.73 KB

Dependencies

Usage examples

Several projects in this repo's /examples directory are using this package:

Description	Live demo	Source
Interactive & reactive image blurhash generator	Demo	Source
Randomized space-filling, nested grid layout generator	Demo	Source
Basic thi.ng/meta-css usage & testbed	Demo	Source
Procedural stochastic text generation via custom DSL, parse grammar & AST transformation	Demo	Source
Scroll-based, reactive, multi-param CSS animation basics	Demo	Source
Demonstates various rdom usage patterns	Demo	Source
Dynamically loaded images w/ preloader state	Demo	Source
rdom drag & drop example	Demo	Source
Basic usage of the declarative rdom-forms generator	Demo	Source
Lazy loading components via @thi.ng/rdom	Demo	Source
Defining & using basic Web Components (with shadow DOM) via @thi.ng/rdom & @thi.ng/meta-css	Demo	Source
Declarative component-based system with central rstream-based pubsub event bus	Demo	Source
3D wireframe textmode demo	Demo	Source
Multi-layer vectorization & dithering of bitmap images	Demo	Source
Interactively drawing to & reading from a WebGL offscreen render texture	Demo	Source

Authors

Karsten Schmidt

If this project contributes to an academic publication, please cite it as:

@misc{thing-meta-css,
  title = "@thi.ng/meta-css",
  author = "Karsten Schmidt",
  note = "https://thi.ng/meta-css",
  year = 2023
}