diff --git a/landing/js/landing.js b/landing/js/landing.js
index 32870df..a2e9951 100644
--- a/landing/js/landing.js
+++ b/landing/js/landing.js
@@ -429,8 +429,22 @@
     function openArchiveWith(names) {
         if (!names || names.length === 0) return;
         var base = location.pathname.replace(/\/[^\/]*$/, '/');
-        var params = ['projects=' + names.map(encodeURIComponent).join(',')];
         var v = new URLSearchParams(location.search).get('v');
+
+        if (names.length === 1) {
+            // Single project → canonical project-subtree URL so the user
+            // can edit the address bar to swap archive.html for
+            // working/, staging/, reviewing/, etc. zddc-server's
+            // availability.go auto-serves the right tool at each.
+            // Multi-project (the `else` branch) keeps the ?projects=
+            // form because there's no single subtree root.
+            var url = base + encodeURIComponent(names[0]) + '/archive.html';
+            if (v) url += '?v=' + encodeURIComponent(v);
+            navigate(url);
+            return;
+        }
+
+        var params = ['projects=' + names.map(encodeURIComponent).join(',')];
         if (v) params.push('v=' + encodeURIComponent(v));
         navigate(base + 'archive.html?' + params.join('&'));
     }
diff --git a/tests/landing.spec.js b/tests/landing.spec.js
index a5bc044..ac0f5dc 100644
--- a/tests/landing.spec.js
+++ b/tests/landing.spec.js
@@ -66,7 +66,10 @@ test.describe('Landing page', () => {
         await page.locator('.project-table-row[data-name="197072"]').click();
 
         const navTo = await page.evaluate(() => window.__navTo);
-        expect(navTo).toContain('archive.html?projects=197072');
+        // Single-project click navigates to the project's canonical subtree
+        // (so the user can swap archive.html for working/, staging/, etc.).
+        expect(navTo).toContain('/197072/archive.html');
+        expect(navTo).not.toContain('?projects=');
     });
 
     test('column filters narrow the table; filters persist in URL', async ({ page }) => {
@@ -217,8 +220,11 @@ test.describe('Landing page', () => {
         await page.locator('#openSelectedBtn').click();
 
         const navTo = await page.evaluate(() => window.__navTo);
-        expect(navTo).toContain('archive.html?projects=176109');
+        // After the visibility-filter trims to one project, this collapses
+        // to the single-project path (no ?projects= form).
+        expect(navTo).toContain('/176109/archive.html');
         expect(navTo).not.toContain('197072');
+        expect(navTo).not.toContain('?projects=');
     });
 
     test('legacy presets are migrated to groups on first load', async ({ page }) => {