feat(calendar): improve FAB positioning on mobile and subtle close styling

- Add hasFabRight prop to InputBar for mobile FAB spacing
- InputBar leaves space for FAB on screens under 900px
- Change active FAB style to subtle muted colors instead of bright blue
- Support dark mode for active FAB state

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

apps/calendar/apps/web/src/lib/components/calendar/CalendarToolbar.svelte

@@ -207,12 +207,15 @@
 	}
 
 	.toolbar-fab.active {
-		background: #3b82f6;
-		border-color: #3b82f6;
+		background: rgba(0, 0, 0, 0.05);
+	}
+
+	:global(.dark) .toolbar-fab.active {
+		background: rgba(255, 255, 255, 0.15);
 	}
 
 	.toolbar-fab.active .fab-icon {
-		color: white;
+		color: hsl(var(--color-muted-foreground));
 	}
 
 	.fab-icon {

apps/calendar/apps/web/src/routes/(app)/+layout.svelte

@@ -415,6 +415,7 @@
 				: showCalendarToolbar && !isToolbarCollapsed
 					? '140px'
 					: '70px'}
+			hasFabRight={showCalendarToolbar && !isSidebarMode}
 		/>
 	</div>
 </SplitPaneContainer>