Fix broken anchor

Author: maxschulz-COL

vizro-core/docs/pages/user-guides/custom-css.md

@@ -9,7 +9,7 @@ To make customizations, you need to:
 1. **Change the relevant CSS properties** in your CSS file.
 
 !!! note "For quick visual fixes, you may shortcut by using the `extra` argument"
-    If you want to alter the visual appearance of a single component quickly, or if you are not yet comfortable with creating a CSS file, you could opt for an alternative approach. Many of our models have an `extra` argument, that let's you pass arguments to the underlying Dash component directly. Often these components have a `style` or `className` argument that let's you alter the style directly. You can check the [API reference](../API-reference/models.md) of the model in question. An example of this would be to make the [`Button`][vizro.models.Button] [outlined and green](../user-guides/card-button.md#the-extra-argument-1).
+    If you want to alter the visual appearance of a single component quickly, or if you are not yet comfortable with creating a CSS file, you could opt for an alternative approach. Many of our models have an `extra` argument, that let's you pass arguments to the underlying Dash component directly. Often these components have a `style` or `className` argument that let's you alter the style directly. You can check the [API reference](../API-reference/models.md) of the model in question. An example of this would be to make the [`Button`][vizro.models.Button] [outlined and green](../user-guides/card-button.md).
 
 ## Introduction to Vizro CSS