strip_tags all except some and remove styling from in php ?

// Input string with HTML tags and styling
$input_string = '<p style="color: red">This is <strong>bold text</strong> and <em>italic text</em>.</p>';

// Define the allowed tags
$allowed_tags = '<strong><em>';

// Remove all HTML tags except allowed tags and their attributes
$filtered_string = strip_tags($input_string, $allowed_tags);

// Encode any remaining HTML entities
$filtered_string = htmlspecialchars($filtered_string, ENT_QUOTES, 'UTF-8');

// Output the filtered string
echo $filtered_string;

This is <strong>bold text</strong> and <em>italic text</em>