Why you should make an accessible carrd
A carrd is there to provide information. This information should be easy to find and read.
A quick guide to how to make an accessible carrd
Underline links to distinguish them from regular text.
Label a link as what it is leading to. Examples: youtube.com, an image of a crouton, and a card with accessibility tips. Text links are clearer than image links.
Avoid having link texts that are very few characters. 'x' is very hard to click on and provides no information.
Have text that is distinguishable from the background. As a general rule of thumb, avoid low contrast between the text and background and also avoid neon or otherwise eye-straining text.
For more information on selecting colours for your carrd I've provided the links to 2 sites that adhere to WCAG (Web Content Accessibility Guidelines):
colorsafe is a website that provides colour palettes.
webaim.org has a contrast checker that shows if the background and foreground colours you select pass multiple contrast guidelines.