Hi,
The theme controls the posts layout through its configuration options – you’d need to override the configured value for specific sections by filtering the theme’s options. Something along the lines of:
function child_custom_posts_layouts( $options = array(), $option_name = '' ){
/* possible posts layout values are: 1, 2 or 3 */
if ( is_category( 123 ) ) $options['fluida_magazinelayout'] = 3;
return $options;
}
add_filter( 'option_fluida_settings', 'child_custom_posts_layouts', 11, 2 );
Note that this code is not tested.