How to add new CSS file to new PHP file

Question

I've made a new template file for Wordpress constructing the elements of the page via PHP and Wordpress recognizes the template as such.

Then I wanted to include a CSS file for said template (same folder) and went with the standard:

<link rel="stylesheet" type="text/css" href="style.css">

but for some reason the PHP file does not load the linked CSS settings. if I add

<? include('style.css') ?>

the content of it gets printed onto the page, meaning the php file can read it. So why doesn't it load the CSS settings?

Thanks for any help

Answer 1

CSS links are relative to the current request URI, not your PHP file. Use an absolute path like:

<link rel="stylesheet" href="<?php bloginfo( 'template_url' ) ?>/themesubfolder/style.css" />

Answer 2

Add below code to your functions.php

    function add_script_and_style() {
      // for .css add 
       wp_enqueue_style('my-style', get_template_directory_uri() . '/my_style.css');

       // for .js add
       wp_enqueue_script( 'my-js', get_template_directory_uri() .'/filename.js', false );
    }

    add_action( 'wp_enqueue_scripts', 'add_script_and_style' );

Extra Info: Wordpress standard way to do

wp_enqueue_style function for .css file

AND wp_enqueue_scripts function for .js script file.

Thank you