Styling of Custom Plugin in wordpress -

i have made simple contact form plugin manually , want style without inline styling. made css file style.css styling doesn't worked me. in advance help.

if trying style backend (admin side) can use wp_enqueue_style . check below code . add code in plugin page.

define('plugin_url', plugins_url('', __file__ ) . '/');  add_action( 'admin_enqueue_scripts','my_plgin_style' );  function my_plgin_style(){ wp_enqueue_style('pluginstyle', plugin_url .'style.css'); }