Conditional CSS/JS loading with filemtime() cache busting comes from /inc/core/assets.php, which guards every enqueue with file_exists() checks and context-aware logic.

CSS Architecture

JavaScript Architecture

Header Search Overlay Assets

extrachill_enqueue_navigation_assets() loads nav-menu.js on every page and relies on filemtime() for versions so deployment changes flush caches without touching functions.php.

Shared Tabs & Sidebar Assets

extrachill_register_shared_tabs() leaves the shared tab styles/scripts registered so templates or plugins can enqueue them when needed; the JavaScript manages desktop and accordion behaviors, hash updates, and emits the sharedTabActivated event for integrations.

Sidebar assets (including sidebar.css) load via extrachill_enqueue_sidebar_styles() only when no extrachill_sidebar_content override replaces the sidebar, ensuring widgets render styled content without extra overhead.

View Tracking

The theme does not enqueue a dedicated view-tracking script. View-count storage (ec_post_views) exists for archive sorting, but event capture is handled outside the theme.

Share Assets

inc/core/assets.php registers assets/css/share.css and assets/js/share.js (via extrachill_register_share_assets()), so templates/plugins can enqueue extrachill-share when needed.

Admin/Editor Styles

extrachill_enqueue_admin_styles() enqueues root.css and editor-style.css for post editing screens (post.php, post-new.php), mirroring the frontend design tokens for a consistent editing experience.

Cache Busting & Priorities

Every style and script uses filemtime() on the source file for the version argument, so browsers refresh when files change. The enqueue priorities (5, 10, 20) guarantee root variables load before dependent styles, and the navigation/styles enqueues avoid redundant loading by checking for contextual flags (e.g., is_archive(), is_search(), post types).

Performance Benefits

• Conditional Loading: CSS/JS only executes when necessary (archive styles on archives, sidebar styles when widgets appear)
• Dependency Safety: Root variables come first, ensuring derived styles inherit the correct custom properties
• Cache Busting: Files emit new version numbers whenever their modification time changes
• Minimal Overhead: Each enqueue guards file existence to avoid 404s
• Shared Components: Shared tabs CSS/JS are registered centrally so downstream templates can opt in while keeping their behaviors consistent

Benefit: Browser cache automatically invalidates when files change.

CSS Loading Functions

extrachill_enqueue_root_styles()

Loads root CSS variables and theme colors.

Priority: 5 (loads first)
Dependencies: None
Hook: wp_enqueue_scripts

extrachill_enqueue_main_styles()

Loads badge color styles.

Priority: 10
Dependencies: extrachill-root
Hook: wp_enqueue_scripts

extrachill_modify_default_style()

Loads main theme stylesheet.

Priority: 20 (loads after root)
Dependencies: extrachill-root
Hook: wp_enqueue_scripts

extrachill_enqueue_single_post_styles()

Loads single post styles.

Condition: is_singular('post')
File: /assets/css/single-post.css
Dependencies: extrachill-root, extrachill-style

extrachill_enqueue_archive_styles()

Loads archive page styles.

Condition: is_archive() || is_search() || get_query_var('extrachill_blog_archive')
File: /assets/css/archive.css
Dependencies: extrachill-root, extrachill-style

extrachill_enqueue_search_styles()

Loads search result styles.

Condition: is_search()
File: /assets/css/search.css
Dependencies: extrachill-root, extrachill-style

extrachill_enqueue_shared_tabs()

Registers shared tab styles and scripts so templates or plugins can enqueue them on demand.

Files: shared-tabs.css, shared-tabs.js
Dependencies: extrachill-root for CSS, wp-polyfill and vanilla JS for scripts (no jQuery)

JavaScript Loading

Navigation Scripts

function extrachill_enqueue_navigation_assets() {
    wp_enqueue_style( 'extrachill-nav-styles', ... );
    wp_enqueue_script( 'extrachill-nav-menu', ... );
}

Files: nav-menu.js
Context: All pages
Load Position: Footer (true parameter)

Admin/Editor Styles

function extrachill_enqueue_admin_styles($hook) {
    if ($hook == 'post.php' || $hook == 'post-new.php') {
        wp_enqueue_style( 'extrachill-admin-root', ... );
        wp_enqueue_style( 'extrachill-admin-editor', ... );
    }
}

Hook: admin_enqueue_scripts
Files: root.css, editor-style.css
Context: Post editor pages only

Loading Priority

1. Priority 5: Root CSS variables
2. Priority 10: Badge colors
3. Priority 20: Main stylesheet, page-specific CSS
4. Default: Navigation, utility styles

File Existence Checks

All enqueue functions check file existence before loading:

$css_path = get_stylesheet_directory() . '/assets/css/archive.css';
if ( file_exists( $css_path ) ) {
    wp_enqueue_style( ... );
}

Performance Benefits

Conditional Loading: CSS/JS only loads when needed
Dependency Management: Proper load order ensures root variables available
Cache Busting: Automatic version updates on file changes
Minimal Overhead: File existence checks prevent 404 errors

Disabling Sticky Header

The sticky header can be disabled via filter:

// Disable sticky header
add_filter( 'extrachill_enable_sticky_header', '__return_false' );

Asset Directory Structure

assets/
  /css/
    root.css              # CSS variables, theme colors
    style.css             # Main stylesheet (loaded via get_stylesheet_uri)
    taxonomy-badges.css   # Taxonomy badge colors
    single-post.css       # Single post styles
    archive.css           # Archive page styles
    search.css            # Search result styles
    shared-tabs.css       # Tab interface styles
    share.css             # Social share buttons
    sidebar.css           # Sidebar component styles
    editor-style.css      # Block editor styles
    embed.css             # Embed iframe styles
    network-dropdown.css  # Network dropdown styles
  /js/
    nav-menu.js           # Header search overlay
    shared-tabs.js        # Tab interface logic
    mini-dropdown.js      # Small dropdown helper (dependency for share)
    share.js              # Share button interactions
  /fonts/
    extrachill.svg        # Icon sprite with QR/download icons