Please note what I said. You can't use a relative href to a style sheet in WordPress.
Also, since you're using the standard style sheet name, you don't need to include it anyway. WordPress automatically uses style.css if it's located in the child theme's directory. You just need to make sure that the file contains the mandatory comments block as the first lines in style.css and that it includes the parent's style sheet by containing the following @import statement immediately after the mandatory comment block:
After the @import statement you add the style rules specific to your child.
Your child theme folder should contain the mandatory style sheet with the contents I detail above in this post, plus any template files that are different from the parent theme's equivalents and any template files that do not exist in the parent such as template files for custom page types.
A minimal child theme contains only the style.css file formatted as above, with just the comments and the @import statement. Such a minimal child theme would look and behave exactly like its parent.