Fix x-axis tick interval calculation (there were too many, especially on mobile)

src/components/simulation-chart.tsx

@@ -53,16 +53,46 @@ const SimulationChart = ({
   const totalHours = (parseInt(simulationDays, 10) || 3) * 24;
   const dispDays = parseInt(displayedDays, 10) || 2;
 
-  // Dynamically calculate tick interval based on displayed days
-  // Aim for ~40-50 pixels per tick for readability
+  // Calculate chart dimensions
+  const [containerWidth, setContainerWidth] = React.useState(1000);
+  const containerRef = React.useRef<HTMLDivElement>(null);
+
+  React.useEffect(() => {
+    const updateWidth = () => {
+      if (containerRef.current) {
+        setContainerWidth(containerRef.current.clientWidth);
+      }
+    };
+
+    updateWidth();
+    window.addEventListener('resize', updateWidth);
+    return () => window.removeEventListener('resize', updateWidth);
+  }, []);
+
+  const simDays = parseInt(simulationDays, 10) || 3;
+
+  // Y-axis takes ~80px, scrollable area gets the rest
+  const yAxisWidth = 80;
+  const scrollableWidth = containerWidth - yAxisWidth;
+
+  // Dynamically calculate tick interval based on available pixel width
+  // Aim for ~46px per label to avoid overlaps on narrow screens
   const xTickInterval = React.useMemo(() => {
-    // Scale interval with displayed days: 1 day = 1h, 2 days = 2h, 3-4 days = 3h, 5+ days = 6h
-    if (dispDays <= 1) return 1;
-    if (dispDays <= 2) return 2;
-    if (dispDays <= 4) return 3;
-    if (dispDays <= 6) return 4;
-    return 6;
-  }, [dispDays]);
+    const MIN_PX_PER_TICK = 46;
+    const intervals = [1, 2, 3, 4, 6, 8, 12, 24];
+
+    const pxPerDay = scrollableWidth / Math.max(1, dispDays);
+    const ticksPerDay = Math.floor(pxPerDay / MIN_PX_PER_TICK);
+
+    // Plenty of room: allow hourly ticks
+    if (ticksPerDay >= 16) return 1;
+    // Extremely tight: show one tick per day boundary
+    if (ticksPerDay <= 0) return 24;
+
+    const idealInterval = 24 / ticksPerDay;
+    const selected = intervals.find((value) => value >= idealInterval);
+    return selected ?? 24;
+  }, [dispDays, scrollableWidth]);
 
   // Generate ticks for continuous time axis
   const chartTicks = React.useMemo(() => {
@@ -207,28 +237,6 @@ const SimulationChart = ({
     return Array.from(dataMap.values()).sort((a, b) => a.timeHours - b.timeHours);
   }, [combinedProfile, templateProfile, daysWithDeviations]);
 
-  // Calculate chart dimensions
-  const [containerWidth, setContainerWidth] = React.useState(1000);
-  const containerRef = React.useRef<HTMLDivElement>(null);
-
-  React.useEffect(() => {
-    const updateWidth = () => {
-      if (containerRef.current) {
-        setContainerWidth(containerRef.current.clientWidth);
-      }
-    };
-
-    updateWidth();
-    window.addEventListener('resize', updateWidth);
-    return () => window.removeEventListener('resize', updateWidth);
-  }, []);
-
-  const simDays = parseInt(simulationDays, 10) || 3;
-
-  // Y-axis takes ~80px, scrollable area gets the rest
-  const yAxisWidth = 80;
-  const scrollableWidth = containerWidth - yAxisWidth;
-
   // Calculate chart width for scrollable area
   const chartWidth = simDays <= dispDays
     ? scrollableWidth