Tara theme gives you an easy way to add custom CSS styles that override theme default styles. This feature is designed to meet the needs of administrators who would like to add their own CSS to their Drupal website.
Styles created with this feature will render only when your website default theme is Tara.
How to add custom CSS
Custom CSS can be added from theme settings page.
Home Administration Appearance Appearance settings Tara
Enable custom css option and enter your custom css codes.