feat(calendar): hover tooltip, light theme grid, UX polish

- Hover tooltip on event cells (pointer:fine only, position:fixed bypasses overflow-hidden)
  — shows title + right-aligned time, max 3 events, "+N weitere"
- Grid background changed to himmel-100 (light), all text tokens updated to dark
- Today cell: wald-200 green background + wald-400 outline
- Empty day cells: subtle bg-himmel-50/40 tint
- Event badge larger on desktop (sm:min-w-4.5 sm:h-4.5 sm:text-[10px])
- Weekday headers: font-semibold text-himmel-800
- Calendar takes full width inside widget (removed max-w-2xl cap)
- Web Share API per event (navigator.share / clipboard fallback, Kopiert\! toast)
- Subscribe bar: webcal:// on Apple, direct ICS download on other platforms

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

src/lib/components/blocks/CalendarBlock.svelte

@@ -405,6 +405,24 @@
         t(T.calendar_weekday_so),
     ]);
 
+    let hasHover = $state(false);
+    let tooltipDay = $state<string | null>(null);
+    let tooltipPos = $state({ x: 0, y: 0 });
+
+    function showTooltip(e: MouseEvent, key: string) {
+        if (!hasHover) return;
+        const r = (e.currentTarget as HTMLElement).getBoundingClientRect();
+        tooltipPos = { x: r.left + r.width / 2, y: r.top };
+        tooltipDay = key;
+    }
+    function hideTooltip() {
+        tooltipDay = null;
+    }
+
+    const tooltipEvents = $derived(
+        tooltipDay ? (eventsByDay.get(tooltipDay) ?? []) : [],
+    );
+
     let feedHost = $state("");
     const webcalUrl = $derived(
         feedHost ? `webcal://${feedHost}/api/kalender.ics` : "#",
@@ -474,6 +492,9 @@
 
     onMount(() => {
         feedHost = window.location.host;
+        hasHover = window.matchMedia(
+            "(hover: hover) and (pointer: fine)",
+        ).matches;
         tickTimer = setInterval(() => {
             nowMs = Date.now();
         }, 60_000);
@@ -852,13 +873,13 @@
        Tag-Grid. Klick auf Tag filtert Liste unten. -->
     <div
         bind:this={widgetEl}
-        class="calendar-widget bg-himmel-800 text-himmel-100 p-4"
+        class="calendar-widget bg-himmel-100 text-himmel-900 p-4"
     >
-        <div class="mx-auto max-w-2xl">
+        <div class="w-full">
             <div class="flex items-center justify-between gap-2 mb-4">
                 <button
                     type="button"
-                    class="p-2 rounded-xs text-himmel-100 hover:bg-himmel-700 hover:text-himmel-50 transition-colors"
+                    class="p-2 rounded-xs text-himmel-800 hover:bg-himmel-200 hover:text-himmel-900 transition-colors"
                     aria-label={t(T.calendar_prev_month)}
                     onclick={prevMonth}
                 >
@@ -869,12 +890,12 @@
                     />
                 </button>
                 <span
-                    class="text-sm font-medium text-himmel-100 capitalize whitespace-nowrap"
+                    class="text-sm font-medium text-himmel-900 capitalize whitespace-nowrap"
                     >{monthLabel}</span
                 >
                 <button
                     type="button"
-                    class="p-2 rounded-xs text-himmel-100 hover:bg-himmel-700 hover:text-himmel-50 transition-colors"
+                    class="p-2 rounded-xs text-himmel-800 hover:bg-himmel-200 hover:text-himmel-900 transition-colors"
                     aria-label={t(T.calendar_next_month)}
                     onclick={nextMonth}
                 >
@@ -889,7 +910,7 @@
             <div class="grid grid-cols-7 gap-1.5 text-center text-sm">
                 {#each weekdays as w}
                     <div
-                        class="py-1.5 text-xs font-medium text-himmel-100 opacity-80"
+                        class="py-1.5 text-xs font-semibold text-himmel-800"
                     >
                         {w}
                     </div>
@@ -909,11 +930,13 @@
                             <button
                                 type="button"
                                 class="relative h-10 rounded-xs flex flex-col items-center justify-center min-w-0 transition-colors cursor-pointer {isCurrentMonth
-                                    ? 'text-himmel-100 hover:bg-himmel-700'
-                                    : 'text-himmel-100 opacity-60 hover:opacity-80'} bg-himmel-700/50 font-semibold hover:bg-himmel-600 {isSelected
-                                    ? 'ring-2 ring-himmel-400 bg-himmel-600'
+                                    ? 'text-himmel-900 hover:bg-himmel-200'
+                                    : 'text-himmel-700 opacity-60 hover:opacity-80'} bg-himmel-200/70 font-semibold hover:bg-himmel-300 {isSelected
+                                    ? 'ring-2 ring-himmel-700 bg-himmel-300'
                                     : ''} {isToday ? 'today-cell' : ''}"
                                 onclick={() => selectDay(key)}
+                                onmouseenter={(e) => showTooltip(e, key)}
+                                onmouseleave={hideTooltip}
                                 aria-pressed={isSelected}
                                 aria-current={isToday ? "date" : undefined}
                                 aria-label="{d.toLocaleDateString('de-DE', {
@@ -928,7 +951,7 @@
                             >
                                 <span class="text-xs">{d.getDate()}</span>
                                 <span
-                                    class="absolute -bottom-1 -right-1 inline-flex items-center justify-center min-w-3.5 h-3.5 px-0.5 rounded-full text-stein-0 text-[9px] font-medium leading-none {isFuture
+                                    class="absolute -bottom-1 -right-1 inline-flex items-center justify-center min-w-3.5 h-3.5 sm:min-w-4.5 sm:h-4.5 px-0.5 rounded-full text-stein-0 text-[9px] sm:text-[10px] font-medium leading-none {isFuture
                                         ? 'bg-wald-400'
                                         : 'bg-error'}"
                                     aria-hidden="true"
@@ -938,9 +961,9 @@
                             </button>
                         {:else}
                             <div
-                                class="relative h-10 rounded-xs flex flex-col items-center justify-center min-w-0 cursor-default {isCurrentMonth
-                                    ? 'text-himmel-100'
-                                    : 'text-himmel-100 opacity-50'} {isToday
+                                class="relative h-10 rounded-xs flex flex-col items-center justify-center min-w-0 cursor-default bg-himmel-50/40 {isCurrentMonth
+                                    ? 'text-himmel-800'
+                                    : 'text-himmel-600 opacity-50'} {isToday
                                     ? 'today-cell'
                                     : ''}"
                                 aria-current={isToday ? "date" : undefined}
@@ -959,7 +982,29 @@
         </div>
     </div>
 
-    <!-- Events: voll Breite, unten. Akkordeon-Liste, in natürlichem
+    <!-- Hover-Tooltip: fixed-positioned → nicht durch overflow-hidden geclipt.
+       Nur auf pointer:fine Geräten (hasHover). Zeigt max 3 Events des Tages. -->
+    {#if hasHover && tooltipDay && tooltipEvents.length > 0}
+        <div
+            class="cal-tooltip"
+            style="left:{tooltipPos.x}px; top:{tooltipPos.y}px;"
+            aria-hidden="true"
+        >
+            {#each tooltipEvents.slice(0, 3) as ev}
+                <div class="cal-tooltip-row">
+                    <span class="cal-tooltip-title">{ev.title || t(T.calendar_untitled)}</span>
+                    {#if ev.timeStr}
+                        <span class="cal-tooltip-time">{ev.timeStr}</span>
+                    {/if}
+                </div>
+            {/each}
+            {#if tooltipEvents.length > 3}
+                <div class="cal-tooltip-more">+{tooltipEvents.length - 3} weitere</div>
+            {/if}
+        </div>
+    {/if}
+
+  <!-- Events: voll Breite, unten. Akkordeon-Liste, in natürlichem
        Page-Flow (kein internes Scrollen). Kalender-Klick filtert auf
        einen Tag; ohne Filter Liste ab heute, gruppiert nach Tag. -->
     <div class="calendar-events-panel bg-stein-0 border-t border-stein-200">
@@ -1098,6 +1143,7 @@
     .calendar-block .today-cell {
         outline: 2px solid var(--color-wald-400, #84e0a4);
         outline-offset: -2px;
+        background-color: color-mix(in srgb, var(--color-wald-200, #bbf0cf) 40%, transparent);
     }
     /* Event-Rows visuell trennen: Card-Optik mit Urgency-Akzent links,
      Zebra-Stripe ab dem zweiten Eintrag, deutlicher Separator
@@ -1151,6 +1197,77 @@
     .calendar-block .day-group + .day-group {
         border-top: 4px solid var(--color-stein-100, #ede8df);
     }
+    /* Hover-Tooltip: fixed über dem Grid, zeigt Event-Vorschau auf hover.
+       pointer-events:none damit kein mouseenter/leave Loop entsteht. */
+    :global(.cal-tooltip) {
+        position: fixed;
+        z-index: 9999;
+        transform: translateX(-50%) translateY(calc(-100% - 8px));
+        background: #fff;
+        color: var(--color-stein-900, #1c1a17);
+        border: 1px solid var(--color-stein-200, #e0dcd5);
+        border-radius: 4px;
+        padding: 6px 10px;
+        box-shadow: 0 4px 12px rgba(0, 0, 0, 0.12);
+        font-size: 11px;
+        line-height: 1.4;
+        pointer-events: none;
+        min-width: 130px;
+        max-width: 220px;
+    }
+    :global(.cal-tooltip::after) {
+        content: "";
+        position: absolute;
+        top: 100%;
+        left: 50%;
+        transform: translateX(-50%);
+        border: 5px solid transparent;
+        border-top-color: var(--color-stein-200, #e0dcd5);
+    }
+    :global(.cal-tooltip::before) {
+        content: "";
+        position: absolute;
+        top: calc(100% - 1px);
+        left: 50%;
+        transform: translateX(-50%);
+        border: 5px solid transparent;
+        border-top-color: #fff;
+        z-index: 1;
+    }
+    :global(.cal-tooltip-row) {
+        display: flex;
+        align-items: baseline;
+        gap: 4px;
+        padding: 1px 0;
+    }
+    :global(.cal-tooltip-row + .cal-tooltip-row) {
+        border-top: 1px solid var(--color-stein-100, #ede8df);
+        margin-top: 2px;
+        padding-top: 3px;
+    }
+    :global(.cal-tooltip-title) {
+        font-weight: 500;
+        color: var(--color-stein-900, #1c1a17);
+        overflow: hidden;
+        display: -webkit-box;
+        -webkit-line-clamp: 2;
+        -webkit-box-orient: vertical;
+    }
+    :global(.cal-tooltip-time) {
+        font-size: 10px;
+        color: var(--color-stein-500, #7a7469);
+        white-space: nowrap;
+        flex-shrink: 0;
+        margin-left: auto;
+    }
+    :global(.cal-tooltip-more) {
+        font-size: 10px;
+        color: var(--color-stein-500, #7a7469);
+        margin-top: 3px;
+        border-top: 1px solid var(--color-stein-100, #ede8df);
+        padding-top: 3px;
+    }
+
     /* Print: alle <details> geöffnet, Chevrons aus, Day-Groups nicht
      splitten. */
     @media print {