CSS Flex: how to center items vertically and horizontally - YouTube
Align items and justify content - Create Web Page Layouts With CSS - OpenClassrooms
CSS Gap Space with Flexbox
layout - Fill remaining vertical space with CSS using display:flex - Stack Overflow
html - Center divs in body horizontally and vertically with flexbox - Stack Overflow
CSS Flexbox tutorial: How to use flexbox properties
align-items | CSS-Tricks - CSS-Tricks
CSS Guide: Flexbox Cheatsheet and Free Resources
The Flexbox Guide
The Ultimate Guide to Flexbox
html - Flexbox fill available space vertically - Stack Overflow
How to Align Items in a Flex Container - Vertical Centering - Silva Web Designs
css - flexbox vertically split container in HALF - Stack Overflow
flexbox - CSS flex box with vertical content equal full screen distribution - Stack Overflow
CSS Flex Align Vertical: Tutorial (Examples + Illustrations)
Bootstrap Flexbox - examples & tutorial
CSS Flexbox
