The specific PHP file for the transparent header functionality in Astra might not be directly accessible for editing. Astra likely uses a combination of functions and templates to achieve the effect.

However, there are generally two main locations where theme PHP files reside in WordPress:

1. Theme's root directory: This directory contains the main theme files, including style.css, functions.php, and potentially other template files. The transparent header functionality might be implemented using a combination of these files.
2. templates directory: Some themes have a dedicated templates directory containing specific page templates like header.php or page.php. While the transparent header itself might not be in a single file, these template files of https://carxstreetapkz.com/ could include logic to control header behavior.

Finding the relevant files:

Unfortunately, without directly examining the Astra theme code, it's difficult to pinpoint the exact file responsible. However, here's what you can try:

• Astra Documentation: Astra's documentation might offer clues on how the transparent header is achieved. Search their documentation for terms like "transparent header" or "header customization".
• Child Theme Exploration (For Advanced Users): If you're comfortable with code, you can create a child theme for Astra. This allows you to explore the parent theme's files (including functions.php and template files) to see how the transparent header might be implemented.

Important Note: Modifying core theme files directly is not recommended as it can be overwritten during theme updates. A child theme is the safer approach for adding custom code.