Pattern CSS – Inline Block Styles


The missing inline CSS editor for blocks. Very powerful with synced patterns. Pairs well with global styles.

How to

  • Every block will have a new “Additional CSS” settings panel.
  • To target a block, you must use the [block] selector.
  • To target any element inside the block, use the normal CSS selector.
  • Use !important to override your theme styles (use sparingly)


  • Smart loading. Only loads the CSS when the block is present
  • No lock in. The styles are attached to the block attributes
  • Scopes styles to the block so that parent/sibling blocks are not affected
  • It’s fast. CSS is minified and optimized in the browser
  • It’s safe. Invalid, non-spec CSS is never persisted (validated via webassembly sandbox)
  • Supports reusable (synced or not-synced) patterns
  • See changes on the page as you make them
  • Combines adjacent rules (to decrease size)
  • Minifies colors and math functions to simplify according to spec
  • Supports CSS nesting

Star it on GitHub
DM me on Twitter @kevinbatdorf

Basic Example

/* Target the block directly */
[block] {
  background: antiquewhite;
  padding: 2rem;
/* Target any inner elements */
a {
  text-decoration-color: burlywood;
  text-decoration-thickness: 2px;
  text-decoration-style: solid !important;
a:hover {
  text-decoration-color: darkgoldenrod;

/* Output: */
.pcss-a1b7b016{background:#faebd7;padding:2rem}.pcss-a1b7b016 a{text-decoration-color:#deb887;text-decoration-thickness:2px;text-decoration-style:solid!important}.pcss-a1b7b016 a:hover{text-decoration-color:#b8860b}

Supports Media Queries

@media (prefers-color-scheme: dark) {
  [block] {
    border-color: blue;

/* Output: */
@media (prefers-color-scheme:dark){.pcss-cddaa023{border-color:#00f}}

Combines Rules

[block] {
  color: red;
.bar {
  color: red;

/* Output: */
.pcss-3aa0f0fc,.pcss-3aa0f0fc .bar{color:red}

Fixes redundant properties

[block] {
  padding-top: 5px;
  padding-left: 50px;
  padding-bottom: 15px;
  padding-right: 5px;

/* Output: */
.pcss-3aa0f0fc{padding:5px 5px 15px 50px}

Supports CSS nesting

[block] {
  padding: 1rem;
  a {
    color: red;
  background: white;
  /* Including media queries */
  @media (prefers-color-scheme: dark) {
    background: black;

/* Output: */
.pcss-f526bb2d{background:#fff;padding:1rem;& a{color:red}@media (prefers-color-scheme:dark){&{color:#fff;background:#000}}}

Check browser support for CSS nesting


  • Add styles not available in the editor
  • Supports reusable and synced patterns too
  • Will warn you if your CSS is invalid


  1. Activate the plugin through the ‘Plugins’ screen in WordPress


Error about application/wasm mime type

Your server needs to be able to identify the mime type being used. See here:

Can I use something other than [block]?

You can add a custom selector via a PHP constant. It requires setting a type (type, attribute, etc) and the name.

Here’s an example for “foo { color: red }”, where foo will be replaced with .pcss-h3Hso39bsK (or something similar):

Add this to functions.php:

define('PATTERN_CSS_SELECTOR_OVERRIDE', ['name' => 'foo', 'type' => 'type']);


Read all 2 reviews

Contributors & Developers

“Pattern CSS – Inline Block Styles” is open source software. The following people have contributed to this plugin.


“Pattern CSS – Inline Block Styles” has been translated into 1 locale. Thank you to the translators for their contributions.

Translate “Pattern CSS – Inline Block Styles” into your language.

Interested in development?

Browse the code, check out the SVN repository, or subscribe to the development log by RSS.


1.2.3 – 2024-05-09

  • Removed globals like @import, @font-face, and @keyframes (and others)

1.2.2 – 2024-04-19

  • Fixed an issue where CSS media queries using <= were stripped out
  • Removed loading the viewer for users without the edit_css cap
  • Removed the tag stripping output – now only privlidged users can use
  • Updated tests to run on modern WP (by disabling the iframe)

1.2.1 – 2024-02-22

  • Removed the example code and added a useful default
  • Render blocks now work – now adds the id to the main class list

1.2.0 – 2024-02-20

  • Feature: Adds support for CSS nesting
  • Removes the code example on focus and adds it back on blur (if empty)
  • Lets users define an additional block selector
  • Adds a notice that the site logo isn’t currently supported

1.1.0 – 2024-02-18

  • Prevent adding classes to blocks unless CSS is added
  • Force the settings area to the bottom (mainly for custom blocks)

1.0.1 – 2023-11-04

  • Fixed a bug where the it would crash on the pattern manager page

1.0.0 – 2023-07-15

  • Feature: Now supports reusable blocks/patterns
  • Update: Removed the “per page” functionality to limit the scope of this plugin to blocks and reusable patterns only
  • Performance: Added global loading strategy to prevent per block n+1 loading issues
  • Improvement: Added the option to update the CSS selector used for scoping (useful for duplicating blocks)
  • Improvement: Added some examples when no CSS is present
  • Improvement: Removed the public className attribute requirement from the Additional Settings area
  • Improvement: Instead of saving as meta on a post, it now pulls from the attribute directly during page load (via the pre_render_block filter).
  • Fix: Now it will only show on post types with the public setting set to true