fix: Convert to Tailwind v4 @theme syntax for color utilities

- Replaced @tailwind directives with @import "tailwindcss"
- Converted :root CSS variables to @theme block with --color-* naming
- This generates utility classes like .bg-primary, .text-foreground, etc.
- CSS bundle increased from 6.21KB to 18.54KB (all color utilities now present)
- Fixes broken UI where custom colors weren't being applied

Author: TamTunnel

AIGovHub/frontend/src/index.css

@@ -1,45 +1,44 @@
-@tailwind base;
-@tailwind components;
-@tailwind utilities;
+@import "tailwindcss";
 
-@layer base {
-  :root {
-    --background: 0 0% 100%;
-    --foreground: 222.2 84% 4.9%;
-    --card: 0 0% 100%;
-    --card-foreground: 222.2 84% 4.9%;
-    --popover: 0 0% 100%;
-    --popover-foreground: 222.2 84% 4.9%;
-    --primary: 221.2 83.2% 53.3%;
-    --primary-foreground: 210 40% 98%;
-    --secondary: 210 40% 96.1%;
-    --secondary-foreground: 222.2 47.4% 11.2%;
-    --muted: 210 40% 96.1%;
-    --muted-foreground: 215.4 16.3% 46.9%;
-    --accent: 210 40% 96.1%;
-    --accent-foreground: 222.2 47.4% 11.2%;
-    --destructive: 0 84.2% 60.2%;
-    --destructive-foreground: 210 40% 98%;
-    --border: 214.3 31.8% 91.4%;
-    --input: 214.3 31.8% 91.4%;
-    --ring: 221.2 83.2% 53.3%;
-    --radius: 0.5rem;
-    --chart-1: 12 76% 61%;
-    --chart-2: 173 58% 39%;
-    --chart-3: 197 37% 24%;
-    --chart-4: 43 74% 66%;
-    --chart-5: 27 87% 67%;
-  }
+@theme {
+  --color-background: hsl(0 0% 100%);
+  --color-foreground: hsl(222.2 84% 4.9%);
+  --color-card: hsl(0 0% 100%);
+  --color-card-foreground: hsl(222.2 84% 4.9%);
+  --color-popover: hsl(0 0% 100%);
+  --color-popover-foreground: hsl(222.2 84% 4.9%);
+  --color-primary: hsl(221.2 83.2% 53.3%);
+  --color-primary-foreground: hsl(210 40% 98%);
+  --color-secondary: hsl(210 40% 96.1%);
+  --color-secondary-foreground: hsl(222.2 47.4% 11.2%);
+  --color-muted: hsl(210 40% 96.1%);
+  --color-muted-foreground: hsl(215.4 16.3% 46.9%);
+  --color-accent: hsl(210 40% 96.1%);
+  --color-accent-foreground: hsl(222.2 47.4% 11.2%);
+  --color-destructive: hsl(0 84.2% 60.2%);
+  --color-destructive-foreground: hsl(210 40% 98%);
+  --color-border: hsl(214.3 31.8% 91.4%);
+  --color-input: hsl(214.3 31.8% 91.4%);
+  --color-ring: hsl(221.2 83.2% 53.3%);
+  --color-chart-1: hsl(12 76% 61%);
+  --color-chart-2: hsl(173 58% 39%);
+  --color-chart-3: hsl(197 37% 24%);
+  --color-chart-4: hsl(43 74% 66%);
+  --color-chart-5: hsl(27 87% 67%);
+
+  --radius-lg: 0.5rem;
+  --radius-md: calc(0.5rem - 2px);
+  --radius-sm: calc(0.5rem - 4px);
 }
 
 @layer base {
   * {
-    border-color: hsl(var(--border));
+    border-color: var(--color-border);
   }
 
   body {
-    background-color: hsl(var(--background));
-    color: hsl(var(--foreground));
+    background-color: var(--color-background);
+    color: var(--color-foreground);
     margin: 0;
     font-family: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
   }