Fix map re-entry after logo-back and compact welcome for portrait phones

Reset $activeDomain to null when returning to welcome so the next
"Map my knowledge" click re-triggers switchDomain. Add compact landing
styles to the ≤480px portrait breakpoint so the welcome screen fits
on phones without the landscape lock active.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: jeremymanning

index.html

@@ -766,6 +766,13 @@
             /* Hide custom tooltips on touch devices */
             .ui-tooltip { display: none !important; }
 
+            /* ── Welcome screen: compact for small portrait screens ── */
+            #landing { padding: 0.75rem 1rem; overflow-y: auto; }
+            .landing-content h1 { font-size: 1.6rem; margin-bottom: 0.3rem; }
+            .landing-content h2 { font-size: 0.85rem; margin-bottom: 0.75rem; }
+            .landing-content p { font-size: 0.8rem; line-height: 1.4; margin-bottom: 0.5rem; }
+            .landing-start-btn { margin-top: 0.75rem; padding: 0.6rem 1.8rem; font-size: 0.95rem; }
+
             /* ── Quiz panel: compact mode buttons + auto-advance for mobile ── */
             .modes-wrapper { gap: 0.2rem; margin-bottom: 0.2rem; padding-bottom: 0.2rem; }
             .mode-btn { width: 28px; height: 28px; font-size: 0.75rem; }

src/app.js

@@ -260,6 +260,8 @@ async function boot() {
         if (landing) landing.classList.remove('hidden');
         if (appEl) appEl.dataset.screen = 'welcome';
         logo.setAttribute('data-tooltip', 'Map my knowledge!');
+        // Reset active domain so re-entering map triggers switchDomain again
+        $activeDomain.set(null);
         // Re-create particle system for the welcome screen
         const pCanvas = document.getElementById('particle-canvas');
         if (pCanvas && allDomainBundle) {