Theme Junkie

This plugin will enable a <a href="https://www.theme-junkie.com/plugins/theme-junkie-custom-css/" rel="nofollow ugc">custom css manager</a> on administration page to add Custom CSS code to your WordPress website. It will automatically override any theme or plugin default styles. It also very useful if you want to add customization to your website but do not want to edit your theme or plugin css files.
It comes with two ways to add the custom css code:
1. Setting 
You can go to Appearance → Custom CSS, then you will see a big box/textarea. Put your css code there.
2. Customizer – Live Preview 
If you want to see the live preview while you adding the custom css code, then you can go to Appearance → Customize, after that open the Custom CSS section tab.
<h4>Features Include:</h4>
<ul>
<li>No configuration needed</li>
<li>Live preview</li>
<li>Easy-to-use</li>
<li>Child theme alternative to add customization</li>
<li>Uninstall procedure</li>
</ul>
<h4>Plugin Info</h4>
<ul>
<li>Developed by <a href="https://www.theme-junkie.com/?utm_source=wporg&utm_medium=text_link&utm_campaign=Site%20Promotion" rel="nofollow ugc">Theme Junkie</a></li>
<li>Check out the <a href="https://github.com/themejunkie/theme-junkie-custom-css" rel="nofollow ugc">Github</a> repo to contribute.</li>
</ul>

TJ Custom CSS

Simply works

Easily to add any Custom CSS code to your WordPress website.

Maxxi E

Khaos Quotes is a robust solution for displaying quotes on your WordPress site. Unlike simple quote plugins, Khaos Quotes focuses on visual customization and ease of management.
Key Features:
<ul>
<li>Quote Management: Add, edit, and delete quotes easily from the admin panel.</li>
<li>Live Preview: See exactly how your quote styling looks while you edit settings.</li>
<li>Visual Customization: Control font size, colors, text strokes (outlines), background colors with opacity, and borders.</li>
<li>Custom Fonts: Upload your own <code>.woff</code> or <code>.woff2</code> font files, or use Google Fonts via URL.</li>
<li>Import/Export: backup your quote library or move it to another site using the built-in JSON system.</li>
<li>Usage: Simply use the shortcode <code>[khaos_random_quote]</code> to display a random quote, or <code>[khaos_random_quote id="5"]</code> to display a specific one.</li>
</ul>

Khaos Quotes

A powerful quote management plugin with live preview, extensive styling options, font uploads, and JSON import/export.

TJ Custom CSS vs Khaos Quotes