/* base-css-contract: v1
   base.css — the floor under the neutral markup (#1001, spec §4.8 + §7.3, decision D16).

   Two jobs, and neither of them is "look good":

     1. A FLOOR, so a theme sheet only has to write what makes it DIFFERENT. Paragraph rhythm, line
        length and "the words are not glued to the edge of the screen" have nothing to do with which
        of the 30 themes is applied, and nobody should write them 30 times.
     2. A FALLBACK, so a page with NO theme sheet is still a page. That is not hypothetical: on dev
        the template overlay is on (deploy/config/manager.dev.json `local.templatePath`), so an old
        site that rebuilds — publishing a blog post is enough — gets today's neutral markup while its
        own theme has no sheet for it. Without this file that page has no spacing at all.

   🔴 NOTHING HERE IS IN A CASCADE LAYER, AND THAT IS THE MECHANISM (spec §4.8, measured twice
   wrong before it was measured right). Tailwind 3.4 compiles to an UNLAYERED bundle (`@layer` in the
   real product CSS: 0 hits), and unlayered rules beat everything inside any layer. So:

     base   .hero__title { … }   a class, (0,1,0) — beats preflight's `h1` (0,0,1) on specificity
     theme  .hero__title { … }   also a class — same specificity, loaded LATER, so it wins on order

   Put base in `@layer base` and the first line stops being true: preflight then beats it, and the
   fallback arm — the only reason this file exists — is exactly where that happens.

   🔴 EVERY SELECTOR HERE IS A SINGLE CLASS. Not a preference: raise the specificity even once
   (`[data-block="hero"] .hero__title` is (0,2,0)) and a theme's `.hero__title` can never override
   it again, whatever the load order. `scripts/base-css-lint.js` refuses anything else.

   🔴 WHAT MAY GO IN HERE, PRACTICALLY: a property a sheet does not set is a property base still
   decides — on the THEMED page too. So the test for a new rule is "would every sheet want to state
   this itself?", and the safe set is the properties the sheets already do state. Checked against all
   three phase-1 sheets before this file was written:

     .hero          display / gap / padding      all three set them → base leaks nothing
     .hero__body    max-width                    all three set it
     .hero__title   font-size / line-height      all three set them
     .hero__sub     margin-top / line-height     all three set them
     .hero__cta     margin-top                   all three set it

   The two deliberate leftovers are `overflow-wrap` and `min-width: 0`: no sheet sets either, both
   only prevent overflow, and a sheet that wanted the overflow back can say so.

   🔴 WHAT IS DELIBERATELY NOT HERE:
   · a max-width on `.hero` — none of the sheets resets it, so it would silently un-full-bleed every
     one of them (hero-media-top paints a band across the whole viewport).
   · `.hero__deco { display: … }` — no sheet sets `display` on it, so anything here would decide it
     for all of them, including hiding a decoration the sheet drew.
   · `.hero__img` / `.hero__cta { display }` — already owned by the structure layer in globals.css
     (#991). One owner per property.

   📌 Phase 2 moves the blocks one at a time and each of those tickets brings its own base rules with
   it. Today: hero (#1008), cta-banner (#1018) and page-header (#1019). */

/* 🔴 这份文件是拼出来的 —— 手改会被下一次 `node scripts/block-build/build-blocks.js` 覆盖，
   而 `scripts/block-build/generated-fresh.test.js` 会在那之前就把它点名。要改一个块的地板，
   改 `blocks/<块>/floor.css`。#1387（设计文档 D20）。

   🔴 有 47 条规则原来一条同时写了好几个块（`.contact-form, .quote-form, …`）。一块一份
   `floor.css` 之后它们按块拆开了，而**解释它们的那段注释只留在按字典序第一个块的 floor.css 里**
   —— 每个块各抄一份的话这份文件要多 43 KB，而它是 `layout.tsx` 直接 <link> 给访客的。
   在别的块里看到一组没有来由的规则时，去那一组里名字最靠前的那个块的 `floor.css` 找。 */