Theme development

I liked this theme here: Yahoo Pure.CSS Framework, but I can not find a guide to creating child themes on this database. Maybe someone will tell you where to look

Hi,

I have a block with an image inserted within the Highlighted Region.

I have tried targeting the block id and the image with CSS, but I cannot get its width to enlarge.

I have even targeted the image source of my block as follows and it still won't enlarge:

How can I adapt the search bar length in Bartik.

I'm not familiar with theming. everything else works great but i would like to have the same length of the search bar as the sidebar two.

or could it even be responsive.

Thank for Help
Lothar

I'm testing on Drupal 8.37 the free Drupal Theme - Custom Theme
it worked fine so far. but now i don't get to the login panel or window.

can somebody tell me, how can I access as an admin directly from the browser the back-end without having a login panel

Thank you for help.

Searched all over for this in my php theme files and all over the admin interface.

when clicking, Account settings > manage fields

Where can I edit the help text for the username/password field? Currently there is help text being generated on hover of the input field, displaying in a black box. Is there anyway to change the behavior of this within Drupal without having to modify tpl.php files?

Unlike created fields, there is no 'edit' button next to these default fields. (username/password)

I have spend days of reading through a ton of documentations & tutorials about theming. The topic is really hard for me scince I have never ever had anything to do with frontend. My knowledge about theming, HTML and php is basically 0, i know a bit of how CSS works.

Please dont ask why I start with front end development then, I just have to.