fix heatmap in stats for bright theme

site/src/components/StatsView.svelte

@@ -6,12 +6,20 @@
   let all: ActivitySummary[] = [];
   let sport: Sport | 'all' = 'all';
   let loading = true;
+  let theme = 'dark';
 
   onMount(async () => {
     const res = await fetch(`${import.meta.env.BASE_URL}data/index.json`);
     const index: BASIndex = await res.json();
     all = index.activities.filter(a => a.privacy !== 'private' && a.distance_m);
     loading = false;
+
+    theme = document.documentElement.getAttribute('data-theme') ?? 'dark';
+    const obs = new MutationObserver(() => {
+      theme = document.documentElement.getAttribute('data-theme') ?? 'dark';
+    });
+    obs.observe(document.documentElement, { attributes: true, attributeFilter: ['data-theme'] });
+    return () => obs.disconnect();
   });
 
   $: activities = sport === 'all' ? all : all.filter(a => a.sport === sport);
@@ -143,20 +151,29 @@
     ];
   }
 
-  // Lerp from zinc-800 bg (#27272a = 39,39,42) toward target color
+  // Base cell color: zinc-800 dark (#27272a=39,39,42) or zinc-200 light (#e4e4e7=228,228,231)
-  function applyIntensity(hex: string, intensity: number): string {
+  $: emptyColor  = theme === 'light' ? '#e4e4e7' : '#27272a';
+  $: baseRgb     = theme === 'light'
+    ? [228, 228, 231] as [number, number, number]
+    : [39,  39,  42]  as [number, number, number];
+
+  // Lerp from base bg color toward target sport color
+  function applyIntensity(hex: string, intensity: number, base: [number, number, number]): string {
     const [tr, tg, tb] = hexToRgb(hex);
-    return `rgb(${Math.round(39 + (tr - 39) * intensity)},${Math.round(39 + (tg - 39) * intensity)},${Math.round(42 + (tb - 42) * intensity)})`;
+    const [br, bg, bb] = base;
+    return `rgb(${Math.round(br + (tr - br) * intensity)},${Math.round(bg + (tg - bg) * intensity)},${Math.round(bb + (tb - bb) * intensity)})`;
   }
 
   // Precompute date→color as a reactive Map so Svelte tracks it directly in
   // the template. (Calling a plain function with a static string arg won't
   // re-trigger when byDate/maxDailyKm change — the Map reference does.)
   $: cellColors = (() => {
+    const base = baseRgb;
+    const empty = emptyColor;
     const m = new Map<string, string>();
     for (const [date, sportMap] of byDateBySport) {
       const total = byDate.get(date) ?? 0;
-      if (total === 0) { m.set(date, '#27272a'); continue; }
+      if (total === 0) { m.set(date, empty); continue; }
       const intensity = 0.12 + pctRank(total, sortedDaily) * 0.88;
       let tr = 0, tg = 0, tb = 0;
       for (const [sp, dist] of sportMap) {
@@ -165,15 +182,15 @@
         tr += cr * w; tg += cg * w; tb += cb * w;
       }
       const blended = `#${Math.round(tr).toString(16).padStart(2,'0')}${Math.round(tg).toString(16).padStart(2,'0')}${Math.round(tb).toString(16).padStart(2,'0')}`;
-      m.set(date, applyIntensity(blended, intensity));
+      m.set(date, applyIntensity(blended, intensity, base));
     }
     return m;
   })();
 
-  // Legend: 6 swatches from dark to full sport color (or neutral for 'all')
+  // Legend: 6 swatches from base bg to full sport color (or neutral for 'all')
-  $: legendColor = sport !== 'all' ? sportColor(sport) : '#00c8ff';
+  $: legendColor = sport !== 'all' ? sportColor(sport) : (theme === 'light' ? '#0284c7' : '#00c8ff');
   $: legendSwatches = [0, 0.18, 0.38, 0.58, 0.78, 1.0].map(t =>
-    t === 0 ? '#27272a' : applyIntensity(legendColor, t)
+    t === 0 ? emptyColor : applyIntensity(legendColor, t, baseRgb)
   );
 
   // Sport chips present in filtered data (for 'all' color key)
@@ -301,12 +318,12 @@
               </div>
               {#each week as date}
                 <div
-                  class="w-[10px] h-[10px] rounded-[2px] {date && activitiesByDate.has(date) ? 'cursor-pointer' : ''} {date && date === pinnedDate ? 'ring-1 ring-white ring-offset-[1px] ring-offset-zinc-950' : ''}"
+                  class="w-[10px] h-[10px] rounded-[2px] {date && activitiesByDate.has(date) ? 'cursor-pointer' : ''} {date && date === pinnedDate ? 'ring-1 ring-white ring-offset-[1px]' : ''}"
-                  style="background:{cellColors.get(date) ?? '#27272a'}"
+                  style="background:{cellColors.get(date) ?? emptyColor}; --tw-ring-offset-color: var(--bg-base)"
                   on:mouseenter={e => onCellEnter(date, e)}
                   on:mouseleave={onCellLeave}
                   on:click={e => onCellClick(date, e)}
-                />
+                ></div>
               {/each}
             </div>
           {/each}