diff --git a/frontend/src/components/Calendar/MainCalendar.jsx b/frontend/src/components/Calendar/MainCalendar.jsx
index 2e90d98..37c9eb4 100644
--- a/frontend/src/components/Calendar/MainCalendar.jsx
+++ b/frontend/src/components/Calendar/MainCalendar.jsx
@@ -14,11 +14,12 @@ import EventTooltip from './EventTooltip'
 import WorkloadHeatmap from './WorkloadHeatmap'
 
 export default function MainCalendar({ onCalendarReady }) {
-  const calRef = useRef(null)
+  const calRef     = useRef(null)
+  const wrapperRef = useRef(null)
   const { projects, updateDeliverable: storeUpdate, removeDeliverable } = useProjectStore()
-  const openFocus     = useFocusStore(s => s.openFocus)
+  const openFocus       = useFocusStore(s => s.openFocus)
   const { showHeatmap, toggleHeatmap } = useUIStore()
-  const addToast      = useToastStore(s => s.addToast)
+  const addToast        = useToastStore(s => s.addToast)
 
   const [modal,       setModal]       = useState({ open: false, deliverable: null, defaultDate: '' })
   const [contextMenu, setContextMenu] = useState(null)
@@ -31,6 +32,18 @@ export default function MainCalendar({ onCalendarReady }) {
     }
   }, [])
 
+  // ResizeObserver: call updateSize() on every frame the container changes width
+  // during the sidebar CSS transition so FullCalendar reflows smoothly
+  useEffect(() => {
+    const el = wrapperRef.current
+    if (!el) return
+    const ro = new ResizeObserver(() => {
+      calRef.current?.getApi().updateSize()
+    })
+    ro.observe(el)
+    return () => ro.disconnect()
+  }, [])
+
   const events = projects.flatMap(p =>
     (p.deliverables || []).map(d => ({
       id:              String(d.id),
@@ -69,12 +82,12 @@ export default function MainCalendar({ onCalendarReady }) {
     })
   }, [storeUpdate, addToast])
 
-  // Click empty date — open add modal
+  // Click empty date - open add modal
   const handleDateClick = useCallback(({ dateStr }) => {
     setModal({ open: true, deliverable: null, defaultDate: dateStr.substring(0, 10) })
   }, [])
 
-  // Date range drag-select — pre-fill modal with start date
+  // Date range drag-select - pre-fill modal with start date
   const handleSelect = useCallback(({ startStr }) => {
     setModal({ open: true, deliverable: null, defaultDate: startStr.substring(0, 10) })
   }, [])
@@ -107,11 +120,11 @@ export default function MainCalendar({ onCalendarReady }) {
       setContextMenu({
         x: e.clientX, y: e.clientY,
         items: [
-          { icon: '✎', label: 'Edit Deliverable', action: () => setModal({ open: true, deliverable, defaultDate: '' }) },
-          { icon: '◎', label: 'Open Focus View',  action: () => openFocus(projectId, deliverableId) },
-          ...(project?.drive_url ? [{ icon: '⬡', label: 'Open Drive Folder', action: () => window.open(project.drive_url, '_blank') }] : []),
+          { icon: '\u2714\ufe0e', label: 'Edit Deliverable', action: () => setModal({ open: true, deliverable, defaultDate: '' }) },
+          { icon: '\u2756', label: 'Open Focus View',  action: () => openFocus(projectId, deliverableId) },
+          ...(project?.drive_url ? [{ icon: '\u2b21', label: 'Open Drive Folder', action: () => window.open(project.drive_url, '_blank') }] : []),
           { separator: true },
-          { icon: '✕', label: 'Delete Deliverable', danger: true,
+          { icon: '\u2715', label: 'Delete Deliverable', danger: true,
             action: async () => {
               if (window.confirm(`Delete "${deliverable.title}"?`)) {
                 await deleteDeliverable(deliverableId); removeDeliverable(deliverableId)
@@ -133,7 +146,7 @@ export default function MainCalendar({ onCalendarReady }) {
               ? 'bg-gold text-surface border-gold'
               : 'bg-surface-elevated border-surface-border text-text-muted hover:border-gold/40 hover:text-gold'
             }`}>
-          {showHeatmap ? '← Calendar' : '⬡ Heatmap'}
+          {showHeatmap ? '\u2190 Calendar' : '\u2b21 Heatmap'}
         </button>
       </div>
 
@@ -142,7 +155,7 @@ export default function MainCalendar({ onCalendarReady }) {
         {showHeatmap ? (
           <WorkloadHeatmap />
         ) : (
-          <div className="h-full p-4 pt-2">
+          <div ref={wrapperRef} className="h-full p-4 pt-2">
             <FullCalendar
               ref={calRef}
               plugins={[dayGridPlugin, timeGridPlugin, interactionPlugin]}