excep tonly one css, don’t load any css

If this code works as excpected and you want to only limit it to front page you need to add a check for front page, like this

function pm_remove_all_styles() {
    if (!is_front_page()) return; // add this

    global $wp_styles;
    $wp_styles->queue = array();
    wp_register_script('hekimscripts_input', get_template_directory_uri() . '/js/stylespure.css', array(), '2.7.1'); // input css
     wp_enqueue_script('hekimscripts_input'); // Enqueue it!
}
add_action('wp_print_styles', 'pm_remove_all_styles', 100);