Front Page with only Right and Left Sidebars

Trying to create front page with just right and left sidebars (also header and footer of course) without content area. I played with Front-page.php and used the code below:

add_filter( 'generate_right_sidebar_width', 'generate_custom_right_sidebar_width' );
function generate_custom_right_sidebar_width()
{
return '25';
}

add_filter( 'generate_left_sidebar_width', 'generate_custom_left_sidebar_width' );
function generate_custom_left_sidebar_width()
{
return '70';
}

As soon as I increase the left sidebar to above 70, sidebars on longer line up.

Appreciate your help. Thank you.