Ordinarily, a page inherits every layout above it, meaning that src/routes/a/b/c/+page.svelte inherits four layouts:
src/routes/+layout.sveltesrc/routes/a/+layout.sveltesrc/routes/a/b/+layout.sveltesrc/routes/a/b/c/+layout.svelte
Occasionally, it's useful to break out of the current layout hierarchy. We can do that by adding the @ sign followed by the name of the parent segment to 'reset' to — for example +page@b.svelte would put /a/b/c inside src/routes/a/b/+layout.svelte, while +page@a.svelte would put it inside src/routes/a/+layout.svelte.
Let's reset it all the way to the root layout, by renaming it to +page@.svelte.
The root layout applies to every page of your app, you cannot break out of it.