Set a link in child theme style.css to jump to #main [closed]

The simple answer is NO, You can not! CSS stand for Cascade Style Sheet which mean to style elements in cascade order. CSS can not change the DOM.

There are two ways to achieve it.

  1. Overriding header.php
  2. Using JavaScript or jQuery (Not recommended)

Method 1: Copy the header.php to your child theme and modify href link with what you want!
Example:

<a class="home-link" href="#main" title="<?php echo esc_attr( get_bloginfo( 'name', 'display' ) ); ?>" rel="home">
    <h1 class="site-title"><?php bloginfo( 'name' ); ?></h1>
    <h2 class="site-description"><?php bloginfo( 'description' ); ?></h2>
</a>

Method 2: Personally I will not recommend it. It is better to have less js as much as possible. If you want to go with this solution you can ask this to stackoverflow.com