Style Engine – Custom CSS & JavaScript

Apply custom CSS and JavaScript to websites globally or per domain. Lightweight, local-only, and fully user-controlled.

<p><strong>Style Engine</strong> lets you apply your own CSS and JavaScript rules to websites. Built for developers, designers, and power users who want precise UI control without touching server-side code.</p> <p>Apply custom CSS and JavaScript to websites globally or per domain. Lightweight, local-only, and fully user-controlled.</p> <p><strong>Key features</strong></p> <ul> <li><strong>Global rules:</strong> Apply CSS/JS to all websites (typography tweaks, accessibility improvements, debugging overlays).</li> <li><strong>Per-website rules:</strong> Domain-isolated rule sets with independent enable/disable controls.</li> <li><strong>SPA navigation support:</strong> CSS automatically re-applies on route changes; JavaScript re-run can be enabled in Settings.</li> <li><strong>Optional live preview:</strong> Live JavaScript preview while typing in the popup editor (can be disabled in Settings).</li> <li><strong>Backup &amp; Restore:</strong> Export/import your full configuration safely with a local JSON backup.</li> <li><strong>Flexible feedback:</strong> Desktop notifications, inline feedback, or silent mode.</li> <li><strong>Multi-language interface:</strong> English, Spanish, German, French, Italian, Dutch, Polish, Portuguese, Turkish, and Russian.</li> </ul> <p><strong>Common use cases</strong></p> <ul> <li>Create custom dark mode rules for sites that don’t support it.</li> <li>Hide intrusive UI elements (banners, promos, sticky bars) with a few selectors.</li> <li>Automate repetitive tasks with small JavaScript snippets.</li> <li>Normalize fonts, spacing, and layout for a consistent browsing experience.</li> </ul> <p><strong>Privacy &amp; safety</strong></p> <ul> <li><strong>No tracking:</strong> Style Engine does not collect browsing data or analytics.</li> <li><strong>Local-only:</strong> Your rules are stored locally in your browser.</li> <li><strong>User-controlled:</strong> The extension runs only the code you explicitly write and save.</li> <li><strong>No remote code:</strong> No external scripts are downloaded or executed.</li> </ul> <p><strong>Links</strong></p> <ul> <li><strong>Website:</strong> <a href="https://glitchid.com/products/style-engine/" target="_blank" rel="noreferrer noopener">https://glitchid.com/products/style-engine/</a></li> <li><strong>Documentation:</strong> <a href="https://glitchid.com/products/style-engine/documentation/" target="_blank" rel="noreferrer noopener">https://glitchid.com/products/style-engine/documentation/</a></li> <li><strong>Privacy:</strong> <a href="https://glitchid.com/privacy/style-engine-privacy/" target="_blank" rel="noreferrer noopener">https://glitchid.com/privacy/style-engine-privacy/</a></li> <li><strong>Terms:</strong> <a href="https://glitchid.com/terms/style-engine-terms/" target="_blank" rel="noreferrer noopener">https://glitchid.com/terms/style-engine-terms/</a></li> <li><strong>Support:</strong> <a href="mailto:[email protected]">[email protected]</a></li> </ul> <p><strong>Publisher:</strong> <strong>Glitchid</strong></p>