Access your blog Theme > and click on Customize > In the left menu, click Advanced.
Header:
- to shrink a header on scroll change Fixed Header value to 2px.
- to increase/decrease your logo size change logo size value to the desired size.
- to disable the popup search form change Popup Search value to 1px.
- to disable live search results while typing in the search query change Live Search Results value to 1px.
Layout:
- to disable sticky sidebar on scroll change Fixed Layout value to 1px.
- to set dark mod as default change Dark Mode Default value to 1px.
- to disable the popup search form change Popup Search value to 1px.
- to disable live search results while typing in the search query change Live Search Results value to 1px.
You can apply the same to other options.