Fix remaining code quality issues

- Fixed method names to use snake_case as required by WordPress coding standards
- Added proper spacing in filter_input function call
- Added periods at the end of inline comments
- Fixed parameter documentation in Plugin class
- Updated CSS media query to use context notation

includes/class-plugin.php

@@ -45,7 +45,7 @@ class Plugin {
     /**
      * Constructor
      *
-     * @param string $plugin_file Main plugin file path.
+     * @param string $pluginFile Main plugin file path.
      * @param string $version Plugin version.
      */
     public function __construct( string $pluginFile, string $version ) {