Fixed multiple bugs

【Contents of fixes】
■Optimization of breadcrumb list
■Adjusted each content style of content builder.
■The slug settings of custom post types are now reflected in the slug of the category.
 Example: If the slug of a custom post type is “sample”, the slug of the category will be “sample_category”.
 ※You will need to click “Save changes” in the permalink settings after changing the slug setting.

The following are the files that have been modified for this update.
【Modified file】
functions.php
style.css
template-parts/breadcrumb.php