Theme development

For a new site I wanted to start clean and subtheme the new Claro. Now how do I make it responsive. From the Claro wiki page I read this:

responsive: give emphasis to what matters; use hierarchy to explain the relation between elements; use predictable patterns; elements adapt and react to inputs.

I have been chasing some issues that arose when an update went bad.

I have the site up and operational now on a generic theme, but for some reason the admin theme is not working.  I get the following when attempting anything that uses the admin theme.  Any and all help greatly appreciated.

The website encountered an unexpected error. Please try again later.

bartik design is still as it was in 2008, it's really unusable at this point and cannot be used without creating a child theme and overriding the styling. 

How long do you plan to keep this going?

We have a total of 328 custom blocks in our Drupal 8 site. I'm not sure at which block count (330, 340, or 350), but at a certain point when a new block is added I am unable to move/drag it. I'm having to constantly delete or prematurely expire custom blocks because I reach that threshold. I cannot find any documentation that states there is a limit to how many custom blocks I can have on a Drupal site. Has anyone else experienced this? If so, what is the fix?

Hello there,

I start to develop drupal five months ago. So I am really new to this drupal development.

So I want to know is there anyway I can change the radio button something beautiful like in modern websites

Because i want to use my form more user friendly with new UIs. I tried to edit radios.html.twig file, but it has a class like this.

<div{{ attributes.addClass('radio') }}>{{ children }}</div>

So this is not like 

Hello all,

I am a bit of a newer developer and I have done some work designing pages in Bootstrap Studio and configuring modules in Drupal in the past, however, for the project I am working on now my client wants to have more specific customization of pages (such as nodes), things like coloring, theming, padding of elements, etc. 

I have been searching online and through the source a bit to try and figure out what tools I need to get started and some of the procedures but I am not quite sure where to get started.