I used w3.css (w3schools.com) and other ideas on that website. Then I thought about it. - The merged result - is this page.
The future is not going to stand still. So there is a need to keep up with what is going on - the time to so was found (COVID-19).
Dimensionalized.com 
This date block
(view source code)
used JavaScript:
switch and break
for background and colors.
Am I online or offline?
Make the columns in this code match the height of the tallest column.
But the columns will automatically stack on screens smaller than 600px.
Right arrow:
Left arrow:
Up arrow:
Down arrow:
Hello World! ➣
Many years ago I spent a fair bit of time learning Java. Then after that, I started learning JavaScript (2 different languages but same concepts). Now to make use of all that, I then needed to learn HTML and CSS(Cascading Style Sheets). Much time went by to the point where I needed time to upgrade my old skills. So along came COVID-19. Now I had the time, or at least, a little bit of time...
This page that you are looking at, is the first page I started with and just threw everything I learned into it. So it might look a bit busy.
Press the X to close this, -or- you can move it.
This code here is a modified 2+ sets of code..
This page was last updated on:
Jan/18/2021 09:30 pm
This Info Snackbar - tooltips/popups shows a message at the bottom of the screen.
When the image is taller than the element[box] containing it, and if it is floated, it would overflow outside of its container boarder.
Clearfix fixes that problem as you can see.This project(CSS, JavaScript) of updating some of my original skills from years ago (Ctrl + C > Ctrl + v then edit test and refine)
began from to almost every weekday.
To be more precise, during COVID-19, til about the end of May June.
Of course I've had a lot less time since the start of June. ... And here it is, the end of 2020.
.
Input your age and click the button:
Cut into this page is an iFrame (otherwise it messes CSS of this page).
If you ADD to the (My To Do List), it won't stay (Just a Demo).
I did not use the Responsive Iframe code as that is a whole new topic!!
