How do I embed custom code in a landing page?

In the page builder, any text block has an html editor. You can access the html editor by clicking the <> source button on the text block toolbar.

CSS:

There are several places to add custom css

1. In the brand (assets->brands)
   
2. In the page builder (Styles Tab)
   
3. In Forms via the form editor
   
4. On the row (click the hamburger on the row)
   

   

Javascript:

You cannot embed javascript into content blocks, thus there are several places to embed javascript code

1. Globally (Administration->Account Settings->Landing Pages [Global Script Tag]
   
2. On the page properties tab
   
3. On the confirmation tab in the form editor
   
4. On the row of a page (hamburger on the row->click the gear)