Help With Child Theme

Hello

Is it possible anyone can tell us where we are going wrong in setting up a child theme for our site please? We have tried all we can think of but can’t get it to work.

The Theme we are using is Whisper

We have set up a child theme folder called – Whisper Child in the themes folder.
We have added functions.php from the original theme and a style.css which contains the following:

/*
Theme Name: Whisper Child
Theme URI: our web address /themes/whisper/
Description: TEST
Author: DC
Version: 1.0
Template: whisper
*/

@import url(“../whisper/style.css”);

/* =Theme customization starts here
——————————————————- */

We have activated the child theme and the site appears fine in a browser.

When we try adding css to the style.css file it seems to have no effect on the site. We must be missing something…
Can anyone advise us how to get the child theme working please?

Any help much appreciated.