diff --git a/src/components/blocks/GridGroup.astro b/src/components/blocks/GridGroup.astro
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+++ b/src/components/blocks/GridGroup.astro
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+---
+// GridGroup — gap:1px hairline-separated card grid wrapper.
+//
+// The separator technique is deliberate house style: a `gap: 1px` over a
+// coloured parent background fakes borders without `border` shorthand. Each
+// direct child paints its own background, which is what makes the 1px seam
+// show. Do not "fix" this into `border`.
+//
+// Built from `.agents/templates/components/grid-group.astro` per task 08 of
+// the Astro refactor. The landing page wraps six `RouteCard` instances in
+// this group; the route-grid layout also pushes each card's link to the
+// bottom, which `RouteCard` carries itself so this wrapper stays generic.
+
+interface Props {
+  /** Accessible label for the group, surfaced as `aria-label` on the section. */
+  label: string;
+  /** Number of columns at the widest breakpoint. */
+  columns?: number;
+}
+
+const { label, columns = 3 } = Astro.props;
+---
+
+<section class="group" aria-label={label}>
+  <div class="grid" style={`--columns: ${columns}`}>
+    <slot />
+  </div>
+</section>
+
+<style>
+  .grid {
+    display: grid;
+    grid-template-columns: repeat(var(--columns), 1fr);
+    gap: 1px; /* hairline separators, drawn by the parent background */
+    background: var(--line);
+  }
+
+  /* Children paint their own background, which is what makes the 1px show. */
+  .grid > :global(*) {
+    background: var(--paper);
+  }
+
+  @media (max-width: 800px) {
+    .grid {
+      grid-template-columns: 1fr;
+    }
+  }
+</style>
diff --git a/src/components/blocks/RouteCard.astro b/src/components/blocks/RouteCard.astro
new file mode 100644
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+++ b/src/components/blocks/RouteCard.astro
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+---
+// RouteCard — one chapter card in the landing page's six-up route grid.
+//
+// Markup mirrors `index.html`'s `<article class="card">` block:
+//   <b>{number}</b><h2>{title}</h2><p>{summary}</p><a href={href}>…</a>
+// The `route-grid` wrapper in landing.css used to push each card's link to the
+// bottom with `display:flex; flex-direction:column; margin-top:auto` on the
+// anchor. That responsibility lives on the card itself now, so the card is
+// self-contained — drop it into any gap:1px group and it lays out the same way.
+//
+// Built from `.agents/templates/components/static-block.astro` per task 08 of
+// the Astro refactor. Steps on:
+//   - number   — the "01" … "06" prefix
+//   - title    — the chapter name (h2)
+//   - summary  — the lede line under the title
+//   - href     — link target for the chapter
+//   - cta      — link text (the index page varies this: "Open chapter →",
+//                "Open lab →", "Open desk →"). Defaults to "Open chapter →".
+
+interface Props {
+  /** Two-digit prefix rendered in the chapter surface red, e.g. "01". */
+  number: string;
+  /** Chapter name shown as the card's h2. */
+  title: string;
+  /** One-line summary under the title. */
+  summary: string;
+  /** Link target for the chapter. */
+  href: string;
+  /** Link text. Varies per destination in the current landing page. */
+  cta?: string;
+}
+
+const { number, title, summary, href, cta = 'Open chapter →' } = Astro.props;
+---
+
+<article class="card">
+  <b>{number}</b>
+  <h2>{title}</h2>
+  <p>{summary}</p>
+  <a href={href}>{cta}</a>
+</article>
+
+<style>
+  /* Mirror chapters.css `.card` + landing.css `.route-grid .card` exactly. */
+  .card {
+    display: flex;
+    min-width: 0;
+    flex-direction: column;
+    min-height: 220px;
+    padding: 28px;
+    background: var(--paper);
+  }
+
+  .card b {
+    color: var(--red);
+    /* token-gap: legacy 24px fixed from chapters.css .card b; no --step-* covers 24px; owner design-system-keeper */
+    font-size: 24px;
+    font-family: ui-monospace, monospace;
+  }
+
+  .card h2 {
+    margin: 18px 0 8px;
+    /* token-gap: legacy 25px fixed from chapters.css .card h2; --step-5 is clamp(24px,3vw,38px) and grows at wide viewports; owner design-system-keeper */
+    font-size: 25px;
+    letter-spacing: -0.04em;
+  }
+
+  .card p {
+    margin: 0 0 14px;
+    color: var(--muted);
+  }
+
+  .card a {
+    /* Push the link to the bottom — carried from landing.css
+       `.route-grid .card a { margin-top: auto }`. */
+    margin-top: auto;
+    color: var(--blue);
+    font-weight: 700;
+    text-decoration: none;
+  }
+
+  .card a:focus-visible {
+    outline: 3px solid var(--red);
+    outline-offset: 2px;
+  }
+
+  @media (max-width: 560px) {
+    .card {
+      min-height: 0;
+    }
+  }
+</style>