The ‘custom’ template has HTML placeholders and naming conventions that can help you do this. They are available from the little question mark on the custom template.
[#DETAILS#] will give you the desired show/hide details label.
Please see our guide here: /hc/en-us/articles/360003921454-Can-I-build-my-own-fully-customized-cookie-consent-banner-
Last updated: 5 May 2018