Tagalys resets all CSS rules within the Tagalys namespace .tagalys-namespace, #tagalys-namespace, so none of your CSS rules will carry over into the Tagalys context by default. This is done to prevent unexpected changes to the layout and UI. The Tagalys CSS rules are then inserted via the included JavaScript. You can override any CSS rule by adding your own rule with highter specifity. In general, you can copy the selector for which you want to override a rule and prepend it with html to increase its specificity.