fix: Extract inline CSS from certificate pages for clean theme integration

- Extracted 200+ lines of inline CSS from certificate-reports-content.php and generate-certificates-content.php to dedicated external CSS files
- Created assets/css/hvac-certificate-reports.css and assets/css/hvac-generate-certificates.css with comprehensive styling for certificate pages
- Updated HVAC_Scripts_Styles to conditionally load specific certificate CSS files based on page URL detection
- Removed all inline <style> tags from certificate content templates to prevent theme integration conflicts
- Maintained complete visual styling compatibility while improving code organization and theme integration
- Certificate pages now follow clean external CSS pattern consistent with other plugin pages

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

includes/class-hvac-scripts-styles.php

@@ -162,6 +162,25 @@ class HVAC_Scripts_Styles {
                 array('hvac-certificates'),
                 $this->version
             );
+            
+            // Load specific certificate page styles
+            if (strpos($_SERVER['REQUEST_URI'], 'certificate-reports') !== false) {
+                wp_enqueue_style(
+                    'hvac-certificate-reports',
+                    HVAC_PLUGIN_URL . 'assets/css/hvac-certificate-reports.css',
+                    array('hvac-certificates'),
+                    $this->version
+                );
+            }
+            
+            if (strpos($_SERVER['REQUEST_URI'], 'generate-certificates') !== false) {
+                wp_enqueue_style(
+                    'hvac-generate-certificates',
+                    HVAC_PLUGIN_URL . 'assets/css/hvac-generate-certificates.css',
+                    array('hvac-certificates'),
+                    $this->version
+                );
+            }
         }
         
         // Organizers pages styles