Swipeable calendar

js/ui/mealCalendar.js

@@ -114,29 +114,20 @@ export function createCalendarWeekdayHeaderHTML(labels = CALENDAR_WEEKDAYS_SHORT
 }
 
 export function createCalendarTopbarHTML({
-    prevId,
     todayId,
-    nextId,
     wrapperClass = 'px-4 pt-4 pb-3 flex items-center justify-end',
     controlsStyle = 'background:rgb(var(--card-soft-rgb));border-color:rgb(var(--card-strong-rgb));',
-    navButtonClass = 'shrink-0 w-7 h-full flex items-center justify-center rounded-full border-0 bg-transparent text-[rgb(var(--text-body-soft-rgb))] transition-colors',
-    todayButtonActiveClass = 'h-full shrink-0 inline-flex min-w-[5.75rem] max-w-[9rem] items-center justify-center rounded-full bg-transparent px-1.5 text-[10px] font-semibold leading-none tabular-nums text-[rgb(var(--text-body-soft-rgb))] active:bg-transparent whitespace-nowrap',
-    todayButtonDimClass = 'h-full shrink-0 inline-flex items-center justify-center rounded-full px-2 text-[10px] font-semibold leading-none text-[rgb(var(--text-faint-rgb))] cursor-default',
+    todayButtonActiveClass = 'h-full shrink-0 inline-flex min-w-[5.75rem] max-w-[9rem] items-center justify-center rounded-full bg-transparent px-3 text-[10px] font-semibold leading-none tabular-nums text-[rgb(var(--text-body-soft-rgb))] active:bg-transparent whitespace-nowrap',
+    todayButtonDimClass = 'h-full shrink-0 inline-flex items-center justify-center rounded-full px-3 text-[10px] font-semibold leading-none text-[rgb(var(--text-faint-rgb))] cursor-default',
 }) {
     return `
         <div class="${wrapperClass}">
-            <div class="flex h-[2.05rem] min-w-0 max-w-[min(100%,20rem)] items-center gap-px rounded-full border px-0.5" style="${controlsStyle}">
-                <button type="button" id="${prevId}" class="${navButtonClass}" aria-label="Poprzedni okres">
-                    <i class="fas fa-chevron-left text-[10px]" aria-hidden="true"></i>
-                </button>
+            <div class="flex h-[2.05rem] min-w-0 max-w-[min(100%,20rem)] items-center justify-center rounded-full border" style="${controlsStyle}">
                 <button type="button" id="${todayId}"
                         class="${todayButtonActiveClass}"
                         data-cal-active-class="${todayButtonActiveClass}"
                         data-cal-dim-class="${todayButtonDimClass}">
                 </button>
-                <button type="button" id="${nextId}" class="${navButtonClass}" aria-label="Następny okres">
-                    <i class="fas fa-chevron-right text-[10px]" aria-hidden="true"></i>
-                </button>
             </div>
         </div>
     `;
@@ -168,7 +159,7 @@ export function syncCalendarTodayButton(buttonEl, isOnToday, selectedDate, optio
         ariaLabelCurrent = 'Widok jest ustawiony na bieżący okres',
     } = options;
     const active = buttonEl.dataset.calActiveClass
-        || 'h-full shrink-0 inline-flex min-w-[5.75rem] max-w-[9rem] items-center justify-center rounded-full bg-transparent px-1.5 text-[10px] font-semibold leading-none tabular-nums text-[rgb(var(--text-body-soft-rgb))] active:bg-transparent whitespace-nowrap';
+        || 'h-full shrink-0 inline-flex min-w-[5.75rem] max-w-[9rem] items-center justify-center rounded-full bg-transparent px-3 text-[10px] font-semibold leading-none tabular-nums text-[rgb(var(--text-body-soft-rgb))] active:bg-transparent whitespace-nowrap';
     if (selectedDate != null) {
         buttonEl.textContent = formatCalendarSelectedDate(selectedDate);
     }
@@ -275,3 +266,208 @@ export function bindCalendarDayClicks(containerEl, onSelect, dayAttr = CALENDAR_
         onSelect(new Date(ts), button, event);
     });
 }
+
+/**
+ * Binds a carousel-style horizontal swipe on zoneEl. Swipe right → onPrev,
+ * swipe left → onNext. Pass `renderGhost(ghostGridEl, direction)` to render
+ * adjacent periods that appear alongside the zone during the gesture. The
+ * callback can return `false` to block that direction (ghost not added).
+ * Returns an unbind function.
+ */
+export function bindCalendarHorizontalSwipe(zoneEl, {
+    onPrev,
+    onNext,
+    renderGhost,
+    threshold = 40,
+    animationMs = 260,
+} = {}) {
+    if (!zoneEl) return () => {};
+
+    let ptrId = null;
+    let startX = 0;
+    let startY = 0;
+    let moved = false;
+    let axisLocked = null;
+    let suppressClickUntil = 0;
+    let animatingNav = false;
+
+    let wrapWidth = 0;
+    let prevGhost = null;
+    let nextGhost = null;
+    let savedStyles = null;
+    let carouselActive = false;
+
+    const prevTouchAction = zoneEl.style.touchAction;
+    const prevUserSelect = zoneEl.style.userSelect;
+    zoneEl.style.touchAction = 'pan-y';
+    zoneEl.style.userSelect = 'none';
+
+    const buildGhost = (direction) => {
+        if (typeof renderGhost !== 'function') return null;
+        const ghost = zoneEl.cloneNode(false);
+        ghost.removeAttribute('id');
+        ghost.style.position = 'absolute';
+        ghost.style.top = '0';
+        ghost.style.width = '100%';
+        ghost.style.pointerEvents = 'none';
+        ghost.setAttribute('aria-hidden', 'true');
+        let ok = true;
+        try {
+            const res = renderGhost(ghost, direction);
+            if (res === false) ok = false;
+        } catch (_) { ok = false; }
+        return ok ? ghost : null;
+    };
+
+    const activateCarousel = () => {
+        if (typeof renderGhost !== 'function') return;
+        wrapWidth = zoneEl.getBoundingClientRect().width;
+        if (wrapWidth <= 0) return;
+        const parentEl = zoneEl.parentElement;
+        savedStyles = {
+            position: zoneEl.style.position,
+            overflow: zoneEl.style.overflow,
+            parentEl,
+            parentOverflow: parentEl ? parentEl.style.overflow : '',
+        };
+        zoneEl.style.position = 'relative';
+        zoneEl.style.overflow = 'visible';
+        if (parentEl) parentEl.style.overflow = 'hidden';
+
+        prevGhost = buildGhost('prev');
+        if (prevGhost) {
+            prevGhost.style.left = `-${wrapWidth}px`;
+            zoneEl.appendChild(prevGhost);
+        }
+        nextGhost = buildGhost('next');
+        if (nextGhost) {
+            nextGhost.style.left = `${wrapWidth}px`;
+            zoneEl.appendChild(nextGhost);
+        }
+
+        zoneEl.style.willChange = 'transform';
+        zoneEl.style.transition = 'none';
+        carouselActive = true;
+    };
+
+    const clearCarousel = () => {
+        if (prevGhost?.parentNode) prevGhost.parentNode.removeChild(prevGhost);
+        if (nextGhost?.parentNode) nextGhost.parentNode.removeChild(nextGhost);
+        prevGhost = null;
+        nextGhost = null;
+        if (savedStyles) {
+            zoneEl.style.position = savedStyles.position;
+            zoneEl.style.overflow = savedStyles.overflow;
+            if (savedStyles.parentEl) savedStyles.parentEl.style.overflow = savedStyles.parentOverflow;
+            savedStyles = null;
+        }
+        zoneEl.style.transition = '';
+        zoneEl.style.transform = '';
+        zoneEl.style.willChange = '';
+        carouselActive = false;
+    };
+
+    const setTranslate = (x, ms) => {
+        zoneEl.style.transition = ms ? `transform ${ms}ms ease` : 'none';
+        zoneEl.style.transform = `translate3d(${x}px, 0, 0)`;
+    };
+
+    const onDown = (e) => {
+        if (ptrId !== null || animatingNav) return;
+        if (e.pointerType === 'mouse' && e.button !== 0) return;
+        startX = e.clientX;
+        startY = e.clientY;
+        ptrId = e.pointerId;
+        moved = false;
+        axisLocked = null;
+        try { zoneEl.setPointerCapture(e.pointerId); } catch (_) {}
+        if (e.pointerType === 'mouse') e.preventDefault();
+    };
+
+    const onMove = (e) => {
+        if (e.pointerId !== ptrId) return;
+        const dx = e.clientX - startX;
+        const dy = e.clientY - startY;
+        if (!moved && (Math.abs(dx) > 6 || Math.abs(dy) > 6)) {
+            moved = true;
+            axisLocked = Math.abs(dx) >= Math.abs(dy) ? 'x' : 'y';
+            if (axisLocked === 'x') activateCarousel();
+        }
+        if (axisLocked === 'x' && carouselActive) {
+            let tx = dx;
+            if (dx > 0 && !prevGhost) tx = dx * 0.15;
+            if (dx < 0 && !nextGhost) tx = dx * 0.15;
+            setTranslate(tx, 0);
+        }
+    };
+
+    const onUp = (e) => {
+        if (e.pointerId !== ptrId) return;
+        const dx = e.clientX - startX;
+        ptrId = null;
+
+        if (!moved || axisLocked !== 'x' || !carouselActive) {
+            if (carouselActive) {
+                setTranslate(0, animationMs);
+                setTimeout(clearCarousel, animationMs + 20);
+            }
+            return;
+        }
+
+        const directionGhost = dx > 0 ? prevGhost : nextGhost;
+        const handler = dx > 0 ? onPrev : onNext;
+        const passes = Math.abs(dx) >= threshold
+            && directionGhost
+            && typeof handler === 'function';
+
+        if (!passes) {
+            setTranslate(0, animationMs);
+            setTimeout(clearCarousel, animationMs + 20);
+            return;
+        }
+
+        suppressClickUntil = performance.now() + 500;
+        animatingNav = true;
+        const targetX = dx > 0 ? wrapWidth : -wrapWidth;
+        setTranslate(targetX, animationMs);
+        setTimeout(() => {
+            clearCarousel();
+            handler();
+            animatingNav = false;
+        }, animationMs);
+    };
+
+    const onClickCapture = (ev) => {
+        if (performance.now() < suppressClickUntil) {
+            ev.stopPropagation();
+            ev.preventDefault();
+            suppressClickUntil = 0;
+        }
+    };
+
+    const onCancel = () => {
+        ptrId = null;
+        moved = false;
+        if (carouselActive) {
+            setTranslate(0, animationMs);
+            setTimeout(clearCarousel, animationMs + 20);
+        }
+    };
+
+    zoneEl.addEventListener('pointerdown', onDown);
+    zoneEl.addEventListener('pointermove', onMove);
+    zoneEl.addEventListener('pointerup', onUp);
+    zoneEl.addEventListener('pointercancel', onCancel);
+    zoneEl.addEventListener('click', onClickCapture, { capture: true });
+
+    return () => {
+        zoneEl.removeEventListener('pointerdown', onDown);
+        zoneEl.removeEventListener('pointermove', onMove);
+        zoneEl.removeEventListener('pointerup', onUp);
+        zoneEl.removeEventListener('pointercancel', onCancel);
+        zoneEl.removeEventListener('click', onClickCapture, { capture: true });
+        zoneEl.style.touchAction = prevTouchAction;
+        zoneEl.style.userSelect = prevUserSelect;
+        if (carouselActive) clearCarousel();
+    };
+}

js/ui/mealPlanEditor.js

@@ -18,12 +18,13 @@ import { dayHasAnyMeal, autoSelectProducts, saveLastProductSelection } from '../
 import { loadPantry } from '../services/pantryShopping.js?v=2';
 import {
     bindCalendarDayClicks,
+    bindCalendarHorizontalSwipe,
     createCalendarTopbarHTML,
     createCalendarWeekdayHeaderHTML,
     isCalendarOnToday,
     renderCalendarGrid,
     syncCalendarTodayButton,
-} from './mealCalendar.js?v=11';
+} from './mealCalendar.js?v=14';
 import { createIngredientCardController, getIngredientCardHTML } from './ingredientCard.js?v=20260417-116';
 
 function esc(s) {
@@ -54,9 +55,7 @@ export function getMealPlanEditorHTML() {
             <div id="mpe-cal-wrap" class="hidden relative z-[1] shrink-0 px-5 pt-3 pb-3 bg-[rgb(var(--app-bg-rgb))]" style="background:rgb(var(--app-bg-rgb)) !important; background-image:none !important;">
                 <div id="mpe-cal-section" class="hidden">
                     ${createCalendarTopbarHTML({
-        prevId: 'mpe-cal-prev',
         todayId: 'mpe-cal-today',
-        nextId: 'mpe-cal-next',
         wrapperClass: 'mb-2 flex items-center justify-end gap-3',
     })}
                     ${createCalendarWeekdayHeaderHTML()}
@@ -618,15 +617,44 @@ export function setupMealPlanEditor() {
         renderCal();
     });
 
-    document.getElementById('mpe-cal-prev')?.addEventListener('click', () => {
-        if (!S.showCal) return;
-        S.calDate = S.calExpanded ? addMonths(S.calDate, -1) : addDays(S.calDate, -7);
-        renderCal();
-    });
-    document.getElementById('mpe-cal-next')?.addEventListener('click', () => {
-        if (!S.showCal) return;
-        S.calDate = S.calExpanded ? addMonths(S.calDate, 1) : addDays(S.calDate, 7);
-        renderCal();
+    bindCalendarHorizontalSwipe(document.getElementById('mpe-cal-grid'), {
+        onPrev: () => {
+            if (!S.showCal) return;
+            S.calDate = S.calExpanded ? addMonths(S.calDate, -1) : addDays(S.calDate, -7);
+            renderCal();
+        },
+        onNext: () => {
+            if (!S.showCal) return;
+            S.calDate = S.calExpanded ? addMonths(S.calDate, 1) : addDays(S.calDate, 7);
+            renderCal();
+        },
+        renderGhost: (ghostGrid, direction) => {
+            if (!S.showCal) return false;
+            const sign = direction === 'prev' ? -1 : 1;
+            const mode = S.calExpanded ? 'month' : 'week';
+            const anchor = S.calExpanded
+                ? addMonths(S.calDate, sign)
+                : addDays(S.calDate, 7 * sign);
+            const today = startOfDay(new Date());
+            const plans = loadPlans();
+            renderCalendarGrid({
+                gridEl: ghostGrid,
+                mode,
+                anchorDate: anchor,
+                selectedDate: S.date,
+                resolveDayState: (day, meta) => {
+                    const isSelected = S.date && sameDay(day, S.date);
+                    const isPast = day.getTime() < today.getTime();
+                    return {
+                        disabled: isPast && !isSelected,
+                        dimmed: (isPast || (meta.mode === 'month' && !meta.inCurrentMonth)) && !isSelected,
+                        showIndicator: meta.mode === 'month'
+                            ? meta.inCurrentMonth && dayHasAnyMeal(plans, day)
+                            : dayHasAnyMeal(plans, day),
+                    };
+                },
+            });
+        },
     });
     document.getElementById('mpe-cal-today')?.addEventListener('click', () => {
         const today = startOfDay(new Date());

js/ui/swipePopoverCalendar.js

@@ -0,0 +1,377 @@
+import { addDays, startOfMonth, startOfWeekMonday } from '../services/dateUtils.js';
+
+const DEFAULT_WEEKDAYS = ['pn', 'wt', 'śr', 'cz', 'pt', 'sb', 'nd'];
+const DEFAULT_MONTHS_LONG = [
+    'Styczeń', 'Luty', 'Marzec', 'Kwiecień', 'Maj', 'Czerwiec',
+    'Lipiec', 'Sierpień', 'Wrzesień', 'Październik', 'Listopad', 'Grudzień',
+];
+
+const DEFAULT_THEME = {
+    selectedBg: 'rgb(var(--card-rgb))',
+    selectedBorder: 'rgb(var(--border-input-rgb))',
+    selectedText: 'rgb(var(--text-emphasis-rgb))',
+    selectedDot: 'rgb(var(--text-emphasis-rgb))',
+    bg: 'rgb(var(--app-bg-rgb))',
+    border: 'rgb(var(--card-raised-rgb))',
+    text: 'rgb(var(--text-body-soft-rgb))',
+    dimmedBg: 'transparent',
+    dimText: 'rgb(var(--text-faint-rgb))',
+    dimOpacity: 0.58,
+    dot: 'rgb(var(--text-faint-rgb))',
+};
+
+function dateKeyLocal(date) {
+    const y = date.getFullYear();
+    const m = String(date.getMonth() + 1).padStart(2, '0');
+    const d = String(date.getDate()).padStart(2, '0');
+    return `${y}-${m}-${d}`;
+}
+
+function keyToDate(key) {
+    return new Date(`${key}T00:00:00`);
+}
+
+function normalizeMonth(date) {
+    return startOfMonth(date instanceof Date ? date : new Date());
+}
+
+function monthLabel(date, monthsLong) {
+    return `${monthsLong[date.getMonth()]} ${date.getFullYear()}`;
+}
+
+function dayRange(aKey, bKey) {
+    const a = keyToDate(aKey);
+    const b = keyToDate(bKey);
+    const [from, to] = a <= b ? [a, b] : [b, a];
+    const out = [];
+    for (let d = new Date(from); d <= to; d = addDays(d, 1)) out.push(dateKeyLocal(d));
+    return out;
+}
+
+export function createSwipePopoverCalendarHTML({
+    idPrefix,
+    weekdays = DEFAULT_WEEKDAYS,
+    monthLabelTextClass = 'text-[10px] font-semibold leading-none tabular-nums whitespace-nowrap',
+}) {
+    const weekdayHeader = `
+        <div class="grid grid-cols-7 gap-1.5 text-center text-[8px] font-medium uppercase tracking-wide mb-1 leading-none" style="color:rgb(var(--text-dim-rgb));">
+            ${weekdays.map((d) => `<div>${d}</div>`).join('')}
+        </div>
+    `;
+    const gripLeft = `
+        <div data-swc-grip aria-hidden="true" style="position:absolute; left:0; top:50%; transform:translateY(-50%); width:0.76rem; height:1rem; pointer-events:none; opacity:0.66;">
+            <span style="position:absolute; left:0; top:50%; transform:translateY(-50%); width:1.5px; height:1.22rem; border-radius:999px; background:rgba(var(--text-faint-rgb),0.84);"></span>
+            <span style="position:absolute; left:0.16rem; top:50%; transform:translateY(-50%); width:1.5px; height:1.0rem; border-radius:999px; background:rgba(var(--text-faint-rgb),0.74);"></span>
+            <span style="position:absolute; left:0.34rem; top:50%; transform:translateY(-50%); width:1.5px; height:0.56rem; border-radius:999px; background:rgba(var(--text-faint-rgb),0.62);"></span>
+        </div>
+    `;
+    const gripRight = `
+        <div data-swc-grip aria-hidden="true" style="position:absolute; right:0; top:50%; transform:translateY(-50%); width:0.76rem; height:1rem; pointer-events:none; opacity:0.66;">
+            <span style="position:absolute; right:0; top:50%; transform:translateY(-50%); width:1.5px; height:1.22rem; border-radius:999px; background:rgba(var(--text-faint-rgb),0.84);"></span>
+            <span style="position:absolute; right:0.16rem; top:50%; transform:translateY(-50%); width:1.5px; height:1.0rem; border-radius:999px; background:rgba(var(--text-faint-rgb),0.74);"></span>
+            <span style="position:absolute; right:0.34rem; top:50%; transform:translateY(-50%); width:1.5px; height:0.56rem; border-radius:999px; background:rgba(var(--text-faint-rgb),0.62);"></span>
+        </div>
+    `;
+
+    return `
+        <div class="pb-3 px-3 flex items-center justify-end gap-3">
+            <div class="flex h-[2.05rem] min-w-0 max-w-[min(100%,20rem)] items-center justify-center rounded-full border" style="background:rgb(var(--app-bg-rgb)); border-color:rgb(var(--card-raised-rgb));">
+                <span id="${idPrefix}-month-label" class="h-full shrink-0 inline-flex min-w-[5.75rem] max-w-[9rem] items-center justify-center px-3 ${monthLabelTextClass}" style="color:rgb(var(--text-body-soft-rgb));"></span>
+            </div>
+        </div>
+        <div id="${idPrefix}-viewport" style="overflow:hidden; position:relative; touch-action:pan-y;">
+            <div id="${idPrefix}-track" style="display:flex; align-items:flex-start; position:relative; will-change:transform;">
+                <div class="swc-panel" data-panel="prev" style="flex-shrink:0; pointer-events:none; position:relative; overflow:hidden;">
+                    ${weekdayHeader}
+                    <div id="${idPrefix}-prev-grid" class="grid grid-cols-7 gap-1.5"></div>
+                    ${gripLeft}
+                    ${gripRight}
+                </div>
+                <div class="swc-panel" data-panel="current" style="flex-shrink:0; position:relative; overflow:hidden;">
+                    ${weekdayHeader}
+                    <div id="${idPrefix}-grid" class="grid grid-cols-7 gap-1.5"></div>
+                    ${gripLeft}
+                    ${gripRight}
+                </div>
+                <div class="swc-panel" data-panel="next" style="flex-shrink:0; pointer-events:none; position:relative; overflow:hidden;">
+                    ${weekdayHeader}
+                    <div id="${idPrefix}-next-grid" class="grid grid-cols-7 gap-1.5"></div>
+                    ${gripLeft}
+                    ${gripRight}
+                </div>
+            </div>
+        </div>
+    `;
+}
+
+export function initSwipePopoverCalendar({
+    idPrefix,
+    selectionMode = 'single',
+    monthsLong = DEFAULT_MONTHS_LONG,
+    theme = DEFAULT_THEME,
+    getMonthAnchor,
+    setMonthAnchor,
+    getSelectionKeys,
+    onSelectionCommit,
+    resolveDayState,
+    panelHandlePx = null,
+    panelHandleRatio = 0.045,
+    panelHandleMin = 10,
+    panelHandleMax = 16,
+}) {
+    const monthLabelEl = document.getElementById(`${idPrefix}-month-label`);
+    const gridEl = document.getElementById(`${idPrefix}-grid`);
+    const prevGridEl = document.getElementById(`${idPrefix}-prev-grid`);
+    const nextGridEl = document.getElementById(`${idPrefix}-next-grid`);
+    const track = document.getElementById(`${idPrefix}-track`);
+    const viewport = document.getElementById(`${idPrefix}-viewport`);
+    if (!gridEl || !track || !viewport) {
+        return {
+            render: () => {},
+            reapplyLayout: () => {},
+            resetTrackPosition: () => {},
+        };
+    }
+
+    const MOVE_THRESHOLD = 6;
+    const SWIPE_THRESHOLD = 40;
+    const ANIMATION_MS = 260;
+
+    let viewportWidth = 0;
+    let panelWidth = 0;
+    let panelHandle = 0;
+    let dragHandleWidth = 0;
+    let restOffset = 0;
+    let animatingNav = false;
+
+    const panels = Array.from(track.querySelectorAll('.swc-panel'));
+
+    const syncGripVisibility = (showAdjacent = false) => {
+        panels.forEach((panel) => {
+            const isCurrent = panel.dataset.panel === 'current';
+            panel.querySelectorAll('[data-swc-grip]').forEach((grip) => {
+                grip.style.opacity = (isCurrent || showAdjacent) ? '0.66' : '0';
+            });
+        });
+    };
+
+    const applyLayout = () => {
+        const vw = viewport.clientWidth || viewport.getBoundingClientRect().width;
+        if (!vw) return;
+        viewportWidth = vw;
+        const computedHandle = panelHandlePx == null
+            ? Math.round(vw * panelHandleRatio)
+            : panelHandlePx;
+        panelHandle = Math.max(panelHandleMin, Math.min(panelHandleMax, computedHandle));
+        dragHandleWidth = panelHandle;
+        panelWidth = vw;
+        restOffset = -panelWidth;
+        panels.forEach((panel) => {
+            panel.style.width = `${panelWidth}px`;
+            panel.style.boxSizing = 'border-box';
+            panel.style.paddingLeft = `${panelHandle}px`;
+            panel.style.paddingRight = `${panelHandle}px`;
+        });
+        track.style.transition = 'none';
+        track.style.transform = `translate3d(${restOffset}px, 0, 0)`;
+        syncGripVisibility(false);
+    };
+
+    const resetTrackPosition = () => {
+        track.style.transition = 'none';
+        track.style.transform = `translate3d(${restOffset}px, 0, 0)`;
+        syncGripVisibility(false);
+    };
+
+    const setDragTranslate = (dx, ms) => {
+        track.style.transition = ms ? `transform ${ms}ms ease` : 'none';
+        track.style.transform = `translate3d(${restOffset + dx}px, 0, 0)`;
+    };
+
+    const getSelectedSet = (previewSelection = null) => {
+        const raw = previewSelection ?? getSelectionKeys();
+        if (Array.isArray(raw)) return new Set(raw);
+        if (typeof raw === 'string' && raw) return new Set([raw]);
+        return new Set();
+    };
+
+    const renderMonthGrid = (targetGrid, monthAnchor, selectedSet) => {
+        if (!targetGrid) return;
+        const first = startOfMonth(monthAnchor);
+        const gridStart = startOfWeekMonday(first);
+        const cells = Array.from({ length: 42 }, (_, i) => addDays(gridStart, i));
+        targetGrid.innerHTML = cells.map((day) => {
+            const dk = dateKeyLocal(day);
+            const inCurrentMonth = day.getMonth() === first.getMonth();
+            const isSelected = selectedSet.has(dk);
+            const resolved = (typeof resolveDayState === 'function'
+                ? resolveDayState(day, { inCurrentMonth, isSelected })
+                : {}) || {};
+            const disabled = !!resolved.disabled;
+            const dimmed = !!resolved.dimmed;
+            const showDot = !!resolved.showDot;
+
+            let bg;
+            let borderColor;
+            let text;
+            let borderClass = 'border';
+            if (isSelected) {
+                bg = theme.selectedBg;
+                borderColor = theme.selectedBorder;
+                text = theme.selectedText;
+            } else if (dimmed) {
+                bg = theme.dimmedBg;
+                borderColor = 'transparent';
+                text = theme.dimText;
+                borderClass = 'border-0';
+            } else {
+                bg = theme.bg;
+                borderColor = theme.border;
+                text = theme.text;
+            }
+            const opacity = dimmed && !isSelected ? String(theme.dimOpacity ?? 0.58) : '1';
+            const dotColor = isSelected ? theme.selectedDot : theme.dot;
+            const tag = disabled ? 'div' : 'button';
+            const attrs = disabled ? '' : `type="button" data-dk="${dk}"`;
+            const dayClass = disabled ? '' : ' swc-day';
+
+            return `
+                <${tag} ${attrs}
+                    class="mx-auto flex h-[2.05rem] w-full min-w-0 max-w-full items-center justify-center rounded-full ${borderClass}${dayClass} text-xs font-medium leading-tight overflow-hidden"
+                    style="background:${bg}; border-color:${borderColor}; color:${text}; opacity:${opacity}; touch-action:none;">
+                    <span class="relative flex h-full w-full flex-col items-center justify-center">
+                        <span class="text-[13px] font-semibold leading-none ${showDot ? '-translate-y-[0.18rem]' : ''}">${day.getDate()}</span>
+                        ${showDot ? `<span class="absolute left-1/2 w-1 h-1 -translate-x-1/2 rounded-full opacity-75" style="bottom:0.24rem; background:${dotColor};" aria-hidden="true"></span>` : ''}
+                    </span>
+                </${tag}>
+            `;
+        }).join('');
+    };
+
+    const render = (previewSelection = null) => {
+        const anchor = normalizeMonth(getMonthAnchor());
+        const selectedSet = getSelectedSet(previewSelection);
+        if (monthLabelEl) monthLabelEl.textContent = monthLabel(anchor, monthsLong);
+        renderMonthGrid(gridEl, anchor, selectedSet);
+        renderMonthGrid(prevGridEl, new Date(anchor.getFullYear(), anchor.getMonth() - 1, 1), selectedSet);
+        renderMonthGrid(nextGridEl, new Date(anchor.getFullYear(), anchor.getMonth() + 1, 1), selectedSet);
+        applyLayout();
+    };
+
+    const commitNavigation = (monthDelta) => {
+        animatingNav = true;
+        const targetDx = monthDelta < 0 ? panelWidth : -panelWidth;
+        setDragTranslate(targetDx, ANIMATION_MS);
+        setTimeout(() => {
+            const anchor = normalizeMonth(getMonthAnchor());
+            setMonthAnchor(startOfMonth(new Date(anchor.getFullYear(), anchor.getMonth() + monthDelta, 1)));
+            render();
+            resetTrackPosition();
+            animatingNav = false;
+        }, ANIMATION_MS);
+    };
+
+    if (selectionMode === 'range') {
+        let dragStart = null;
+        let dragCurrent = null;
+        let dragging = false;
+        gridEl.addEventListener('pointerdown', (e) => {
+            if (animatingNav) return;
+            const btn = e.target.closest('.swc-day');
+            if (!btn) return;
+            e.stopPropagation();
+            dragStart = btn.dataset.dk;
+            dragCurrent = btn.dataset.dk;
+            dragging = true;
+            gridEl.setPointerCapture(e.pointerId);
+            render([dragStart]);
+        });
+        gridEl.addEventListener('pointermove', (e) => {
+            if (!dragging || animatingNav) return;
+            e.preventDefault();
+            const el = document.elementFromPoint(e.clientX, e.clientY);
+            const btn = el?.closest('.swc-day');
+            if (btn?.dataset.dk && btn.dataset.dk !== dragCurrent) {
+                dragCurrent = btn.dataset.dk;
+                render(dayRange(dragStart, dragCurrent));
+            }
+        });
+        gridEl.addEventListener('pointerup', () => {
+            if (!dragging) return;
+            dragging = false;
+            const range = dayRange(dragStart, dragCurrent);
+            dragStart = null;
+            dragCurrent = null;
+            if (typeof onSelectionCommit === 'function') onSelectionCommit(range);
+            render();
+        });
+        gridEl.addEventListener('pointercancel', () => {
+            dragging = false;
+            dragStart = null;
+            dragCurrent = null;
+            render();
+        });
+    } else {
+        gridEl.addEventListener('click', (e) => {
+            const btn = e.target.closest('.swc-day');
+            if (!btn) return;
+            if (typeof onSelectionCommit === 'function') onSelectionCommit(btn.dataset.dk);
+            render();
+        });
+    }
+
+    let ptrId = null;
+    let startX = 0;
+    let startY = 0;
+    let moved = false;
+    let axis = null;
+
+    viewport.addEventListener('pointerdown', (e) => {
+        if (animatingNav || ptrId !== null) return;
+        if (e.pointerType === 'mouse' && e.button !== 0) return;
+        if (!panelWidth) applyLayout();
+        const rect = viewport.getBoundingClientRect();
+        const localX = e.clientX - rect.left;
+        const inLeft = localX <= dragHandleWidth;
+        const inRight = localX >= (viewportWidth - dragHandleWidth);
+        if (!inLeft && !inRight) return;
+        ptrId = e.pointerId;
+        startX = e.clientX;
+        startY = e.clientY;
+        moved = false;
+        axis = null;
+        try { viewport.setPointerCapture(e.pointerId); } catch (_) {}
+    });
+
+    viewport.addEventListener('pointermove', (e) => {
+        if (e.pointerId !== ptrId || animatingNav) return;
+        const dx = e.clientX - startX;
+        const dy = e.clientY - startY;
+        if (!moved && (Math.abs(dx) > MOVE_THRESHOLD || Math.abs(dy) > MOVE_THRESHOLD)) {
+            moved = true;
+            axis = Math.abs(dx) >= Math.abs(dy) ? 'x' : 'y';
+            if (axis === 'x') syncGripVisibility(true);
+        }
+        if (axis === 'x') setDragTranslate(dx, 0);
+    });
+
+    const endGesture = (e) => {
+        if (e && e.pointerId !== ptrId) return;
+        ptrId = null;
+        if (!moved || axis !== 'x') return;
+        const dx = e ? e.clientX - startX : 0;
+        if (Math.abs(dx) >= SWIPE_THRESHOLD) commitNavigation(dx > 0 ? -1 : 1);
+        else {
+            setDragTranslate(0, ANIMATION_MS);
+            setTimeout(() => syncGripVisibility(false), ANIMATION_MS + 20);
+        }
+        moved = false;
+        axis = null;
+    };
+
+    viewport.addEventListener('pointerup', endGesture);
+    viewport.addEventListener('pointercancel', endGesture);
+    window.addEventListener('resize', applyLayout);
+
+    return { render, reapplyLayout: applyLayout, resetTrackPosition };
+}