How to Customize CSS in Blogspot. The Blogger Template Designer allows you to insert custom CSS code to change your blog's appearance. You can access the advanced settings of the Template Designer ...

PreloadX - Custom Preloader Customize your WordPress site's preloader with multiple CSS preloaders and flexible background options, including colors, gradients, or images, with adjustable foreground ...

But you are mixing the features here. Are you talking about preloading (this will actually lower the score and it's been removed as an option), about critical path CSS or about lazy loading assets? Or ...

Preloading With The Display Property First, let's create a class with display set to none and add it to the HEAD section of the home page: ...