First page issues

[vessemer]

1. It's not obvious at least for me :( how to proceed to the next pages:

2. The slicing range button appears far beneath the view element:

Checklist before submitting

• I have confirmed this using the officially supported Docker Compose setup using the local.yml configuration and ensured that I built the containers again and they reflect the most recent version of the project at the HEAD commit on the master branch
• I have searched through the other currently open issues and am confident this is not a duplicate of an existing bug
• I provided a minimal code snippet or list of steps that reproduces the bug.
• I provided screenshots where appropriate
• I filled out all the relevant sections of this template

[louisgv]

Another issue with this page is that the "Start New Case" button is being placed in a bad position. E.g, right behind the image and is easily hidden by the imagery if the screen is small.

For #288 , I moved the button to the header as a temporary solution.