Scroll the document by default; a bounded region is a page's own opt-in

AGENTS.md

@@ -278,6 +278,16 @@ Revisit only if the stated reason stops holding.
   it means disclosure rather than popup: the nav tree. `shell.ejs` hand-rolls the same block for the
   profile menu (its trigger composes escaped user values and its one item is a CSRF POST form) — keep
   the two in step.
+- **The document scrolls; a bounded scroll region is opt-in.** `.app` is `min-height: 100dvh`, not
+  a `100dvh` box with `overflow: hidden`: the sidebar is `position: sticky` at full height and the
+  topbar sticks too, so both stay put while the content column flows with the page. A page that wants
+  a region scrolling inside it — a board of full-height columns, a table whose header stays put —
+  gives that region a height and scrolls within it; `.table-wrap` is `overflow-x: auto` and nothing
+  more until a page does. The inverse default clipped the first long page that did not know the rule
+  (2026-09-06), silently, in every engine: nothing in a test or a console says a page is unreachable
+  below the fold. Document scrolling is also what keeps find-in-page, anchor links, keyboard paging,
+  print and reader mode working. The `visual.spec.ts` wheel test holds this; scrollIntoView would not,
+  since a script can scroll an overflow-hidden box and a reader cannot.
 - **`ICON_NAMES` (`src/ui/icons.ts`) is a host-owned registry, not a frozen plugin contract**, so it
   is deliberately not re-exported from `@plainpages/plugin-api`. The palette may narrow when the last reference
   to an id goes, and a plugin needing one gets it re-registered in the same change. Accepted cost: an

README.md

@@ -933,6 +933,10 @@ recovery / front pages — so it looks identical signed in or out and just shows
 anonymous visitor. The sidebar collapses to a burger on a narrow screen; a page wanting a
 chrome-free layout opts out with the shell's `menu: false`.
 
+**The document scrolls.** The sidebar and topbar stay put on their own, and a page is reachable
+below the fold without adding a scroll region. A region that should scroll *inside* the page — a
+board of full-height columns, a table whose header stays put — sets its own height and `overflow`.
+
 ## Building blocks
 
 Plainpages is a **component library, not a page generator** — reusable EJS partials + TS helpers,

e2e-tests/visual.spec.ts

@@ -28,6 +28,20 @@ test.beforeEach(async ({ context }) => {
   await context.addCookies([{ name: SESSION_COOKIE, url: BASE_URL, value: devSession() }]);
 });
 
+// The shell must never clip a page: a body that does not scroll itself has to reach the reader
+// through the document. A key press, not scrollIntoView — a script can scroll an overflow-hidden
+// box, a reader cannot. End rather than the wheel: Firefox's synthetic wheel never reaches the
+// document.
+test("a page taller than the window scrolls, so its last control can be reached", async ({ page }) => {
+  await page.setViewportSize({ width: 1280, height: 240 });
+  await page.goto("/dashboard");
+
+  const last = page.locator(".form-actions .btn").last();
+  await expect(last).not.toBeInViewport();
+  await page.keyboard.press("End");
+  await expect(last).toBeInViewport();
+});
+
 test("captures the live pages for review", async ({ page }) => {
   await page.goto("/dashboard");
   await expect(page.locator(".sidebar")).toBeVisible();

public/css/styles.css

@@ -111,7 +111,7 @@ html:has(#theme-light:checked) {
 
 /* ---------- 2. RESET ---------------------------------------- */
 *, *::before, *::after { box-sizing: border-box; }
-html, body { height: 100%; }
+html, body { min-height: 100%; }
 body { margin: 0; background: var(--bg); color: var(--text);
   -webkit-font-smoothing: antialiased; }
 button { font: inherit; color: inherit; }
@@ -148,19 +148,20 @@ summary { list-style: none; cursor: pointer; }
 .ico-sm { width: 14px; height: 14px; }
 
 /* ---------- 3. APP GRID ------------------------------------- */
+/* Not a viewport-height box: the document scrolls, so a page is reachable below the fold without
+   bringing a scroll region of its own (AGENTS.md → UI). */
 .app {
   display: grid;
   grid-template-columns: var(--nav-w) minmax(0, 1fr);
-  height: 100dvh;
-  overflow: hidden;
+  min-height: 100dvh;
 }
 
 /* ---------- 4. SIDEBAR -------------------------------------- */
 .sidebar {
   grid-column: 1;
+  position: sticky; top: 0; height: 100dvh; align-self: start;
   display: flex;
   flex-direction: column;
-  min-height: 0;
   background: var(--surface);
   border-right: 1px solid var(--border);
 }
@@ -331,12 +332,13 @@ span.nav-self { cursor: default; }                 /* static / non-clickable */
 .content {
   grid-column: 2;
   display: flex; flex-direction: column;
-  min-width: 0; min-height: 0;
+  min-width: 0;
   background: var(--bg);
 }
 
 /* topbar (page title + hamburger on mobile) */
 .topbar {
+  position: sticky; top: 0; z-index: 20;
   flex: 0 0 auto; height: 48px;
   display: flex; align-items: center; gap: 12px;
   padding: 0 16px; border-bottom: 1px solid var(--border);
@@ -559,7 +561,8 @@ span.nav-self { cursor: default; }                 /* static / non-clickable */
 .pill-clear:hover { text-decoration: underline; }
 
 /* ---------- 9. TABLE --------------------------------------- */
-.table-wrap { flex: 1 1 auto; min-height: 0; overflow: auto; }
+/* A bounded region is opt-in: give this a height and the header below stays put inside it. */
+.table-wrap { overflow-x: auto; }
 table.table {
   width: 100%; border-collapse: separate; border-spacing: 0;
   font-size: var(--fz); font-variant-numeric: tabular-nums;
@@ -723,4 +726,4 @@ th[aria-sort="descending"] .sort-ico { transform: rotate(180deg); }
 .app-bare { grid-template-columns: minmax(0, 1fr); }
 .app-bare .content { grid-column: 1; }
 /* Auth/landing rendered inside the app shell: a roomy, centered column in the content area. */
-.shell-auth { flex: 1 1 auto; overflow-y: auto; display: flex; justify-content: center; align-items: flex-start; padding: 40px 20px 80px; }
+.shell-auth { flex: 1 1 auto; display: flex; justify-content: center; align-items: flex-start; padding: 40px 20px 80px; }