diff --git a/playwright.foundation.config.ts b/playwright.foundation.config.ts
index d7f4425..dc5b821 100644
--- a/playwright.foundation.config.ts
+++ b/playwright.foundation.config.ts
@@ -2,7 +2,7 @@ import { defineConfig, devices } from "@playwright/test";
 
 export default defineConfig({
   testDir: "./tests/browser",
-  testMatch: ["foundation.spec.ts", "table.spec.ts"],
+  testMatch: ["foundation.spec.ts", "table.spec.ts", "showcase.spec.ts"],
   fullyParallel: false,
   forbidOnly: true,
   retries: 0,
diff --git a/preview/components.html b/preview/components.html
index 3c7271d..3d67b78 100644
--- a/preview/components.html
+++ b/preview/components.html
@@ -28,7 +28,10 @@
   header.site { display: flex; flex-wrap: wrap; align-items: baseline; gap: var(--dds-space-16); padding: var(--dds-space-40) 0 var(--dds-space-24); }
   header.site h1 { font-size: var(--dds-typo-title-1-font-size); line-height: var(--dds-typo-title-1-line-height); font-weight: var(--dds-typo-title-1-font-weight); margin: 0; }
   header.site .src { font-size: var(--dds-typo-label-font-size); color: var(--dds-color-text-muted); margin-left: auto; font-family: var(--dds-font-family-mono); }
-  header.site nav { display: flex; gap: var(--dds-space-16); flex-basis: 100%; margin-top: var(--dds-space-4); }
+  /* wrap: without it the row can't shrink past the sum of each link's
+   * narrowest word, and on a phone every command splits after its "--".
+   * Row gap 8 on 16px lines = 24px pitch, the web target-size floor. */
+  header.site nav { display: flex; flex-wrap: wrap; gap: var(--dds-space-8) var(--dds-space-16); flex-basis: 100%; margin-top: var(--dds-space-4); }
   header.site nav a {
     font-family: var(--dds-font-family-mono);
     font-size: var(--dds-typo-label-font-size);
diff --git a/preview/icons.html b/preview/icons.html
index c6520de..5c37014 100644
--- a/preview/icons.html
+++ b/preview/icons.html
@@ -27,8 +27,11 @@
   header.site { display: flex; flex-wrap: wrap; align-items: baseline; gap: var(--dds-space-16); padding: var(--dds-space-40) 0 var(--dds-space-24); }
   header.site h1 { font-size: var(--dds-typo-title-1-font-size); line-height: var(--dds-typo-title-1-line-height); font-weight: var(--dds-typo-title-1-font-weight); margin: 0; }
   header.site .src { font-size: var(--dds-typo-label-font-size); color: var(--dds-color-text-muted); margin-left: auto; font-family: var(--dds-font-family-mono); }
-  header.site nav { display: flex; gap: var(--dds-space-16); flex-basis: 100%; margin-top: var(--dds-space-4); }
-  header.site nav a { font-family: var(--dds-font-family-mono); font-size: var(--dds-typo-label-font-size); color: var(--dds-color-text-brand); text-decoration: none; }
+  /* wrap: without it the row can't shrink past the sum of each link's
+   * narrowest word, and on a phone every command splits after its "--".
+   * Row gap 8 on 16px lines = 24px pitch, the web target-size floor. */
+  header.site nav { display: flex; flex-wrap: wrap; gap: var(--dds-space-8) var(--dds-space-16); flex-basis: 100%; margin-top: var(--dds-space-4); }
+  header.site nav a { font-family: var(--dds-font-family-mono); font-size: var(--dds-typo-label-font-size); line-height: var(--dds-typo-label-line-height); color: var(--dds-color-text-brand); text-decoration: none; }
   header.site nav a:hover { text-decoration: underline; }
   h2 { font-size: var(--dds-typo-title-2-font-size); line-height: var(--dds-typo-title-2-line-height); font-weight: var(--dds-typo-title-2-font-weight); margin: var(--dds-space-48) 0 var(--dds-space-4); }
   p.note { font-size: var(--dds-typo-body-2-font-size); line-height: var(--dds-typo-body-2-line-height); color: var(--dds-color-text-secondary); margin: 0 0 var(--dds-space-16); max-width: 60em; }
diff --git a/preview/index.html b/preview/index.html
index 03f0709..21a3960 100644
--- a/preview/index.html
+++ b/preview/index.html
@@ -98,7 +98,10 @@
     padding: 2px 8px; border-radius: 9999px;
   }
   header.site .src { font-size: 13px; color: var(--muted); margin-left: auto; }
-  header.site nav { display: flex; gap: 16px; flex-basis: 100%; margin-top: 4px; }
+  /* wrap: without it the row can't shrink past the sum of each link's
+     narrowest word, and on a phone every command splits after its "--".
+     Row gap 8 on 16px lines = 24px pitch, the web target-size floor. */
+  header.site nav { display: flex; flex-wrap: wrap; gap: 8px 16px; flex-basis: 100%; margin-top: 4px; }
   header.site nav a {
     font-family: "Geist Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
     font-size: 13px; line-height: 16px; color: var(--brand-text); text-decoration: none;
diff --git a/tests/browser/showcase.spec.ts b/tests/browser/showcase.spec.ts
new file mode 100644
index 0000000..8fcb73b
--- /dev/null
+++ b/tests/browser/showcase.spec.ts
@@ -0,0 +1,46 @@
+import { expect, test } from "@playwright/test";
+import { fileURLToPath } from "node:url";
+
+// The showcase pages are shipped as-is to devslab.kr/dds/ (the site vendors
+// them), so a phone-width overflow here is a phone-width overflow there.
+// Served from disk under a stand-in origin: icons.html imports icons.js as an
+// ES module, which Chromium refuses over file://.
+const origin = "http://dds.showcase.test";
+const repo = new URL("../../", import.meta.url);
+const pages = ["index", "components", "icons"] as const;
+const widths = [320, 360, 375, 1440] as const;
+
+test.beforeEach(async ({ page }) => {
+  await page.route(`${origin}/**`, (route) => {
+    const path = new URL(route.request().url()).pathname.slice(1);
+    return route.fulfill({ path: fileURLToPath(new URL(path, repo)) });
+  });
+});
+
+for (const name of pages) {
+  for (const width of widths) {
+    test(`preview/${name}.html fits ${width}px and keeps each nav command on one line`, async ({ page }) => {
+      await page.setViewportSize({ width, height: 800 });
+      await page.goto(`${origin}/preview/${name}.html`);
+
+      const { scrollWidth, clientWidth } = await page.evaluate(() => ({
+        scrollWidth: document.documentElement.scrollWidth,
+        clientWidth: document.documentElement.clientWidth,
+      }));
+      expect(scrollWidth, "the page must not scroll sideways").toBeLessThanOrEqual(clientWidth);
+
+      // A nowrap nav squeezes each link to its narrowest word, so "> ./dds
+      // --components" stacks as "> ./dds --" / "components". Wrapping between
+      // links keeps every command whole.
+      const links = await page.locator("header.site nav a").evaluateAll((elements) => elements.map((element) => ({
+        text: element.textContent,
+        height: element.getBoundingClientRect().height,
+        lineHeight: parseFloat(getComputedStyle(element).lineHeight),
+      })));
+      expect(links.length).toBeGreaterThan(0);
+      for (const link of links) {
+        expect(link.height, `"${link.text}" must render on a single line`).toBeLessThanOrEqual(link.lineHeight + 0.5);
+      }
+    });
+  }
+}