Sometime when you upgrade Magento to latest version you will have this error in the console

Password Protect CMS Page

to protect any page with a password in an easy way you can add this script to the top of the page

<script type="text/javascript">
    var password = 'password123'
    var retVal = prompt("Enter your password : ", "your password here");
    if(retVal !== password)
    {
        location.assign('');
    }
</script>

One of the best code I saw is the below code which is a good way to change the URL without refresh the page, here is the code

How many times you tried to install Magento 2 and later you could not see the website working !!, How many times you tried to search for these sentences 

"Magento 2 css not working"

"Magento 2 js not working"

"Magento 2 404 page not found" because of the static files?

Now here is the solution, and easily it is the missed .htaccess (for apache)

by quick look at this path "{magento root}/pub/static", you will see that you missed the .htaccess file

To change the time please copy this file 

vendor\magento\module-ui\view\frontend\web\js\view\messages.js

to your them to be in this path

app\design\frontend\{vendor}\{theme}\Magento_Ui\web\js\view\messages.js

then modify this function 

You can use this script to detect the screen size as you want