WordPress child theme css changes does not effect my site. Could you please help ?

I think I found a solution to kind of the same problem. First check your functions.php in the child theme folder, and try to add only the following:

<?php
function my_theme_enqueue_styles() {

    $parent_style = 'parent-style'; // This is 'twentyfifteen-style' for the Twenty Fifteen theme.

    wp_enqueue_style( $parent_style, get_template_directory_uri() . '/style.css' );
    wp_enqueue_style( 'child-style',
        get_stylesheet_directory_uri() . '/style.css',
        array( $parent_style ),
        wp_get_theme()->get('Version')
    );
}
add_action( 'wp_enqueue_scripts', 'my_theme_enqueue_styles' );
?>

Where parent-style is the same $handle used in the parent theme when it registers its stylesheet. For example, if the parent theme is twentyfifteen, by looking in its functions.php for its wp_enqueue_style() call, you can see the tag it uses there is 'twentyfifteen-style'.

You can find these instructions in https://codex.wordpress.org/Child_Themes

Second step, is to check your style.css in the child theme folder and add correctly the header as shown in the WP Codex

/*
 Theme Name:   Twenty Fifteen Child
 Theme URI:    http://example.com/twenty-fifteen-child/
 Description:  Twenty Fifteen Child Theme
 Author:       John Doe
 Author URI:   http://example.com
 Template:     twentyfifteen
 Version:      1.0.0
 License:      GNU General Public License v2 or later
 License URI:  http://www.gnu.org/licenses/gpl-2.0.html
 Tags:         light, dark, two-columns, right-sidebar, responsive-layout, accessibility-ready
 Text Domain:  twenty-fifteen-child
*/

Change the example text above with your details relevant to the theme, specially put importance to Theme URI. Also here comes the trick, the Version number. Every time you change something to your child .css change the version in the text above to an increment or as you like. Changing this helps to enqueue correctly.

Everything is explained in the WP Codex link I mentioned above. Hope this helps, since it worked for me.

Cant change css :( tried both solutions did not work. @2017

Hi Mop, Could you please paste screen shot for Child theme and Parent Theme header. And one more thing , please check your child theme folder name.

Regards, Saikat