Put Alerts in the main navigation (after Climate) across the interactive pages
and the SEO/climate pages, so it's a discoverable entry point rather than only the
header bell. The bell stays; this is an additional way in.
The signed-out /alerts gate now leads with a clear "What are weather alerts?"
explainer — what they do, how the percentile threshold works, and an example —
above the sign-in / create-account button, so visitors understand the feature
before signing in.
The extra nav item pushed the inline header past ~800px into a horizontal
scrollbar; trim the tab padding in the 641–1000px band so the row fits again
(phones already collapse into the hamburger).