Change the sidebar widths depending on page

gistfile1.php

add_filter( 'generate_right_sidebar_width','generate_right_sidebar_width_custom', 50 );
function generate_right_sidebar_width_custom()
{
	if ( is_page( 'page-slug' ) ) {
		return '20'; // 20% for yourURL.com/page-slug
	}
	
	if ( is_page( 'another-slug' ) ) {
		return '30'; // 30% for yourURL.com/another-slug
	}
	
	// If neither of the above are true, return your default value
	return '25'; // 25% or whatever your default is
}

add_filter( 'generate_left_sidebar_width','generate_left_sidebar_width_custom', 50 );
function generate_left_sidebar_width_custom()
{
	if ( is_page( 'custom-slug' ) ) {
		return '50'; // 50% for yourURL.com/custom-slug
	}
	
	if ( is_page( 'one-more-slug' ) ) {
		return '15'; // 15% for yourURL.com/one-more-slug
	}
	
	// If neither of the above are true, return your default value
	return '25'; // 25% or whatever your default is
}