Modify Search Field with Template Creator

Hello Cédric, I am frustrated. I have tried to implement your advice. But nothing changes.
 

I give you a screenshot to show you where you must put the code
then let me know

I have implemented it this way but again it has no effect. It must have something to do with this version of the template, because it actually works fine with another template created with the Template Generator. I may have changed the code: input.search-query {
    width: 100% !important;
}
in a different place in the template and I can't find it anymore. It may also be related to the target "Right - Position_6".

Don't stress about it, you certainly have more important things to do. I'll leave it like this for now.

have you updated your template after you added the code ? I don't see the custom.css file in your source code, which means that it is not created at all
it shall be in
YOUR_SITE/templates/YOUR_TEMPLATE/css/custom.css

Please see the attachments!

may be that you are not editing the correct template because the one I see in your page is
/gsv7c-gsvtt

please check and let me know