feat: enhance calendar styling for today and holiday events

- Added CSS styles for the "today" cell to visually distinguish it with a solid background and border when it has external events.
- Updated the margin for day elements to improve layout consistency.
- Introduced new styles for duty, unavailable, vacation, and event indicator dots on the "today" cell to enhance visual contrast and clarity.
- Improved overall calendar aesthetics to better represent different event types.

webapp/style.css

@@ -176,6 +176,13 @@ body {
   border: 1px solid color-mix(in srgb, var(--today) 35%, transparent);
 }
 
+/* Today + external calendar: same solid "today" look as weekday, plus a border to show it has external events */
+.day.today.holiday {
+  background: var(--today);
+  color: var(--bg);
+  border: 1px solid color-mix(in srgb, var(--bg) 50%, transparent);
+}
+
 .day {
   cursor: pointer;
 }
@@ -185,7 +192,7 @@ body {
   flex-wrap: wrap;
   justify-content: center;
   gap: 2px;
-  margin-top: 2px;
+  margin-top: 6px;
 }
 
 .day-indicator-dot {
@@ -211,6 +218,20 @@ body {
   background: var(--accent);
 }
 
+/* On "today" cell: dots darkened for contrast on --today background */
+.day.today .day-indicator-dot.duty {
+  background: color-mix(in srgb, var(--duty) 65%, var(--bg));
+}
+.day.today .day-indicator-dot.unavailable {
+  background: color-mix(in srgb, var(--unavailable) 65%, var(--bg));
+}
+.day.today .day-indicator-dot.vacation {
+  background: color-mix(in srgb, var(--vacation) 65%, var(--bg));
+}
+.day.today .day-indicator-dot.events {
+  background: color-mix(in srgb, var(--accent) 65%, var(--bg));
+}
+
 /* === Day detail panel (popover / bottom sheet) */
 /* Блокировка фона при открытом bottom sheet: прокрутка и свайпы отключены */
 body.day-detail-sheet-open {