Not bad at all,
Though let me suggest a pep8 linter, it will help your code look really clean.
PyCharm (Built in linting for python)
VSCode (has a pep8 linter extension)
SublimeLinter (pep8 linter extension for Sublime Text)
Not bad at all. Here's some basic things i notice missing:
Box shadow on main content box
corner radius left is dead
inline css image missing (notebook paper thingy)
size scale for top right button
font scale
margin/padding-left for content
inactive/unselected bubble circle
Again i'm just...
Also i'll suggest: if you're serious about this you should probably build an app along with it. Or to connect to it, whatever.
Think of your typical employee, probably not that tech savvy, but is hip enough to know how to use a smart phone.
If there's an app this employee can download to...