Confluence sucks for requirements, design capture even for software development but alternatives that are focused purely on design are rare. You should try and expand into design capture for SW development as well.
As in front-end engineering? Or software _architecture_ design? If you mean front-end then this is already something we enable as we have integrations with front-end coding tools like Storybook and have plans to build on that :)
Meant software _architecture_ design :) Usually no one builds frontends in isolation. So will be good to have something e2e in one place.