zoom-out fallback to default view, pct 3 decimal places

wwwroot/app.js

@@ -67,7 +67,7 @@ async function loadView() {
 
   $('range-label').textContent =
     `${fmtDate(viewFrom)} - ${fmtDate(viewTo)}  (${entryMode ? 'Einträge' : ZOOM_LEVELS[zoomIndex].name})`;
-  $('btn-zoom-out').disabled = zoomStack.length === 0;
+  $('btn-zoom-out').disabled = zoomStack.length === 0 && zoomIndex === 0 && !entryMode;
 
   if (entryMode) {
     const [entries, summary] = await Promise.all([
@@ -337,12 +337,20 @@ function enterEntryMode(bucketStart, bucketEnd) {
 }
 
 function zoomOut() {
-  if (!zoomStack.length) return;
-  const prev = zoomStack.pop();
-  viewFrom  = prev.from;
-  viewTo    = prev.to;
-  zoomIndex = prev.zoom;
-  entryMode = prev.entry;
+  if (zoomStack.length) {
+    const prev = zoomStack.pop();
+    viewFrom  = prev.from;
+    viewTo    = prev.to;
+    zoomIndex = prev.zoom;
+    entryMode = prev.entry;
+  } else {
+    // Reset to default view
+    viewTo = new Date();
+    viewFrom = new Date(viewTo);
+    viewFrom.setDate(viewFrom.getDate() - ZOOM_LEVELS[0].days);
+    zoomIndex = 0;
+    entryMode = false;
+  }
   loadView();
 }
 
@@ -473,5 +481,5 @@ function escAttr(s) {
 }
 
 function pct(cost) {
-  return (cost / WEEKLY_BUDGET * 100).toFixed(2) + '%';
+  return (cost / WEEKLY_BUDGET * 100).toFixed(3) + '%';
 }