Refines grid and viewport layout for scrolling

Improves CSS grid configuration to ensure proper scrolling and content display

Adds grid template columns and width constraints for better responsive behavior
Ensures consistent overflow and layout management across viewport components

wwwroot/css/v2/calendar-v2-layout.css

@@ -116,6 +116,7 @@ swp-grid-container {
   grid-column: 2;
   grid-row: 1 / 3;
   display: grid;
+  grid-template-columns: minmax(0, 1fr);
   grid-template-rows: subgrid;
   overflow: hidden;
 }
@@ -136,6 +137,7 @@ swp-header-viewport {
 swp-content-viewport {
   overflow: hidden;
   min-height: 0;
+  width: 100%;
 }
 
 swp-header-track {