Which simple CMS to choose for a landing or mini-site?

Question

CMS

We need the most simple CMS with the following set of functions:
1) The most simple templating (header / menu / content / footer)
2) Creating and editing pages, html / php, CNC support.
3) The simplest file manager for uploading pictures or documents (uploaded - received a link to the picture - inserted into the page)
4) Preferably not a separate admin panel, but editing (or at least switching to it) directly from the pages.
A nice addition would be the ability to create a "product catalog" with an arbitrary set of fields.
Thank you!

Answer 1

Landing can be done without CMS, using some kind of landing generator or wordpress.

Answer 2

www.getmdl.io