Are there best practices for integrating custom CSS styles into a PHP-based forum like phpBB3?

When integrating custom CSS styles into a PHP-based forum like phpBB3, it is recommended to create a custom stylesheet and link it to the forum's overall_header.html file. This way, you can easily manage and update your custom styles without modifying the core forum files. Additionally, using specific CSS classes and IDs in your custom styles will help prevent conflicts with the existing forum styles.

// Create a custom stylesheet file (e.g. custom_styles.css) and place it in the forum's styles directory
// Edit the overall_header.html file in the forum's template directory to link the custom stylesheet

<!-- Add this line within the <head> section of overall_header.html -->
<link href="{T_THEME_PATH}/your_custom_styles.css" rel="stylesheet" type="text/css" />