Index: chapterx-frontend/src/components/ui/Button.tsx
===================================================================
--- chapterx-frontend/src/components/ui/Button.tsx	(revision b62cefc14094ca5ac7154f7d48797a1e6c444935)
+++ chapterx-frontend/src/components/ui/Button.tsx	(revision b62cefc14094ca5ac7154f7d48797a1e6c444935)
@@ -0,0 +1,70 @@
+import React from 'react'
+
+interface ButtonProps extends React.ButtonHTMLAttributes<HTMLButtonElement> {
+  variant?: 'primary' | 'secondary' | 'danger' | 'ghost'
+  size?: 'sm' | 'md' | 'lg'
+  loading?: boolean
+  children: React.ReactNode
+}
+
+export const Button: React.FC<ButtonProps> = ({
+  variant = 'primary',
+  size = 'md',
+  loading = false,
+  children,
+  className = '',
+  disabled,
+  ...props
+}) => {
+  const base =
+    'inline-flex items-center justify-center font-medium rounded-xl transition-all duration-200 focus:outline-none focus:ring-2 focus:ring-offset-2 focus:ring-offset-slate-900 disabled:opacity-50 disabled:cursor-not-allowed'
+
+  const variants = {
+    primary:
+      'bg-gradient-to-r from-indigo-600 to-violet-600 text-white hover:from-indigo-500 hover:to-violet-500 focus:ring-indigo-500 shadow-lg glow-indigo hover:scale-105 active:scale-95',
+    secondary:
+      'bg-slate-700 text-slate-100 hover:bg-slate-600 focus:ring-slate-500 border border-slate-600',
+    danger:
+      'bg-gradient-to-r from-rose-600 to-rose-500 text-white hover:from-rose-500 hover:to-rose-400 focus:ring-rose-500 shadow-lg',
+    ghost:
+      'bg-transparent text-slate-300 hover:bg-slate-800 hover:text-white focus:ring-slate-500 border border-transparent hover:border-slate-600',
+  }
+
+  const sizes = {
+    sm: 'px-3 py-1.5 text-sm gap-1.5',
+    md: 'px-4 py-2 text-sm gap-2',
+    lg: 'px-6 py-3 text-base gap-2',
+  }
+
+  return (
+    <button
+      className={`${base} ${variants[variant]} ${sizes[size]} ${className}`}
+      disabled={disabled || loading}
+      {...props}
+    >
+      {loading && (
+        <svg
+          className="animate-spin h-4 w-4"
+          xmlns="http://www.w3.org/2000/svg"
+          fill="none"
+          viewBox="0 0 24 24"
+        >
+          <circle
+            className="opacity-25"
+            cx="12"
+            cy="12"
+            r="10"
+            stroke="currentColor"
+            strokeWidth="4"
+          />
+          <path
+            className="opacity-75"
+            fill="currentColor"
+            d="M4 12a8 8 0 018-8V0C5.373 0 0 5.373 0 12h4z"
+          />
+        </svg>
+      )}
+      {children}
+    </button>
+  )
+}