Mary Rose Elbambo

BlockGlow adds a “BlockGlow — Custom CSS” panel to the inspector of every block. Use it to scope custom CSS to a single block instance. The plugin stores CSS in the uploads folder (under uploads/blockglow/) and enqueues the generated CSS file when rendering on the front end. If the uploads directory isn’t writable or file write fails, BlockGlow will fall back to outputting inline styles.
Key features:
<ul>
<li>Adds two block attributes to every block: <code>blockglowCustomCSS</code> and <code>blockglowId</code>.</li>
<li>Inspector panel with a CodeMirror-backed code editor (if WordPress provides it) or a fallback textarea supporting Tab and Shift+Tab outdent.</li>
<li>Live preview inside the block editor: custom CSS is scoped to the block in the editor so you can see the effect while editing.</li>
<li>CSS files are saved to <code>wp-content/uploads/blockglow/blockglow-<id>.css</code> and enqueued on the front end as a linked stylesheet; files are removed automatically when you clear the Custom CSS field.</li>
<li>Graceful fallback to inline styles when file writing isn’t possible.</li>
</ul>
How scoping works:
BlockGlow creates a unique <code>blockglowId</code> for each block instance and scopes your CSS with a wrapper selector like:
<pre><code>[data-blockglow-id="bg-xxxxxxx"] { /* your declarations */ }
</code></pre>
For convenience you can use <code>&</code> as the wrapper shorthand in the editor. Example:
<pre><code>& .my-class { color: red; }
</code></pre>
The plugin will replace <code>&</code> with the wrapper selector for both editor preview and front-end output.
<h3>Support</h3>
If you find issues or want improvements (for example: limiting who can edit per-block CSS, collecting styles into a single head include, or adding an admin UI to manage generated CSS files), open an issue in the repository or reply here and I will assist.

BlockGlow — Per-block Custom CSS

Adds a "Custom CSS" inspector panel to every Gutenberg block and saves per-block CSS files to uploads for front-end enqueuing.

Access Keys

AccessPress Custom CSS is a FREE plugin to add your own custom css to your site that will override plugins and theme’s default stylesheets. With this plugin you can put custom css code without editing your theme and/or your plugins files (really useful in case of any theme/plugin update). This is very easy to use plugin.
<h4>Features:</h4>
<ul>
<li>Add your custom css to a site.</li>
<li>Syntax Highlighter supports(by CodeMirror) color and tab support for write a good css code.</li>
<li>Lightweight – Installs in seconds.</li>
<li>User friendly – very easy to configure and setup.</li>
<li>Super support – get support via email/support forum/online chat.</li>
</ul>
AccessPress Custom CSS works best with every WordPress theme. Its even more remarkable when used with popular themes like VMagazine and AccessPress Parallax.
<h4>Some Useful Links</h4>
<ul>
<li>Support Email: support@accesspressthemes.com</li>
<li>Support Forum Link: http://accesspressthemes.com/support/</li>
<li>Youtube channel link: https://www.youtube.com/watch?v=TjZNcVG3fDE</li>
<li>Facebook link: https://www.facebook.com/AccessPressThemes</li>
</ul>

BlockGlow — Per-block Custom CSS vs AccessPress Custom CSS