Restyle dark theme with blue-tinted palette, card glow, and rounded surfaces

Shift the dark theme from neutral gray to a richer blue-tinted palette
inspired by CharBuilder-style TTRPG apps. Deeper navy background, steel-blue
card surfaces, and visible blue borders create more depth and visual layering.

- Update design tokens: background, card, border, input, muted colors
- Add card-glow utility (radial gradient + blue box-shadow) for card surfaces
- Add panel-glow utility (top-down gradient) for tall panels like stat blocks
- Apply glow and rounded-lg to all card surfaces, dropdowns, dialogs, toasts
- Give outline buttons a subtle fill instead of transparent background
- Active combatant row now uses full border with glow instead of left accent

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

apps/web/src/index.css

@@ -1,14 +1,14 @@
 @import "tailwindcss";
 
 @theme {
-	--color-background: #0f172a;
+	--color-background: #0e1a2e;
 	--color-foreground: #e2e8f0;
-	--color-muted: #64748b;
+	--color-muted: #7a8ba4;
 	--color-muted-foreground: #94a3b8;
-	--color-card: #1e293b;
+	--color-card: #1a2e4a;
 	--color-card-foreground: #e2e8f0;
-	--color-border: #334155;
-	--color-input: #334155;
+	--color-border: #2a5088;
+	--color-input: #2a5088;
 	--color-primary: #3b82f6;
 	--color-primary-foreground: #ffffff;
 	--color-accent: #3b82f6;
@@ -169,6 +169,28 @@
 		concentration-glow 1200ms ease-out;
 }
 
+@utility card-glow {
+	background-image: radial-gradient(
+		ellipse at 50% 50%,
+		oklch(0.35 0.05 250 / 0.5) 0%,
+		transparent 70%
+	);
+	box-shadow:
+		0 0 15px -2px oklch(0.623 0.214 259 / 0.2),
+		inset 0 1px 0 0 oklch(0.7 0.15 259 / 0.1);
+}
+
+@utility panel-glow {
+	background-image: linear-gradient(
+		to bottom,
+		oklch(0.35 0.05 250 / 0.4) 0%,
+		transparent 40%
+	);
+	box-shadow:
+		0 0 20px -2px oklch(0.623 0.214 259 / 0.15),
+		inset 0 1px 0 0 oklch(0.7 0.15 259 / 0.1);
+}
+
 * {
 	scrollbar-color: var(--color-border) transparent;
 	scrollbar-width: thin;