feat: redesign frontend UI with MoonShadow-style dark theme

- Update color scheme to purple/blue gradient accents
- Add modern card layouts with hover effects
- Implement token display with copy button
- Add stats dashboard on home page
- Improve install page with SQLite/MySQL toggle
- Add feature cards for supported functions
- Improve login/register pages with centered layout
- Add admin page with user management table
- Add responsive grid layouts
- Add fade-in animations

web/src/pages/Register.tsx

@@ -1,9 +1,10 @@
 import { useState } from 'react'
+import { Link } from 'react-router-dom'
 
 export default function RegisterPage() {
   const [username, setUsername] = useState('')
   const [password, setPassword] = useState('')
-  const [code, setCode] = useState('')
+  const [confirmPassword, setConfirmPassword] = useState('')
   const [error, setError] = useState('')
   const [success, setSuccess] = useState('')
   const [loading, setLoading] = useState(false)
@@ -12,35 +13,50 @@ export default function RegisterPage() {
     e.preventDefault()
     setError('')
     setSuccess('')
+
+    if (password !== confirmPassword) {
+      setError('两次密码不一致')
+      return
+    }
+
     setLoading(true)
 
     try {
       const res = await fetch('/api/register', {
         method: 'POST',
         headers: { 'Content-Type': 'application/json' },
-        body: JSON.stringify({ username, password, registration_code: code }),
+        body: JSON.stringify({ username, password })
       })
 
       const data = await res.json()
 
-      if (!res.ok) {
+      if (res.ok) {
+        setSuccess('注册成功，请登录')
+        setTimeout(() => {
+          window.location.href = '/login'
+        }, 1500)
+      } else {
         setError(data.error || '注册失败')
-        return
       }
-
-      setSuccess('注册成功，请登录')
-      setTimeout(() => window.location.href = '/login', 2000)
     } catch {
-      setError('网络错误')
+      setError('网络错误，请重试')
     } finally {
       setLoading(false)
     }
   }
 
   return (
-    <div className="container" style={{ maxWidth: '400px', marginTop: '100px' }}>
-      <div className="card">
-        <h1 style={{ marginBottom: '24px', textAlign: 'center' }}>注册</h1>
+    <div className="container-sm">
+      <div className="text-center mb-6" style={{ paddingTop: '80px' }}>
+        <div className="logo" style={{ width: '48px', height: '48px', fontSize: '20px', margin: '0 auto 16px' }}>
+          AC
+        </div>
+        <h1 className="page-title">AntiCaptcha</h1>
+        <p className="text-secondary">验证码识别服务平台</p>
+      </div>
+
+      <div className="card fade-in">
+        <h2 className="text-lg mb-4 text-center">注册</h2>
         
         <form onSubmit={handleSubmit}>
           <div className="form-group">
@@ -68,27 +84,28 @@ export default function RegisterPage() {
           </div>
 
           <div className="form-group">
-            <label className="label">注册码</label>
+            <label className="label">确认密码</label>
             <input
-              type="text"
+              type="password"
               className="input"
-              value={code}
-              onChange={e => setCode(e.target.value)}
-              placeholder="请输入注册码"
+              value={confirmPassword}
+              onChange={e => setConfirmPassword(e.target.value)}
+              placeholder="请再次输入密码"
               required
             />
           </div>
 
-          {error && <div className="error">{error}</div>}
-          {success && <div className="success">{success}</div>}
+          {error && <div className="error mb-4">{error}</div>}
+          {success && <div className="success mb-4">{success}</div>}
 
-          <button type="submit" className="button" style={{ width: '100%' }} disabled={loading}>
+          <button type="submit" className="button button-block button-lg" disabled={loading}>
             {loading ? '注册中...' : '注册'}
           </button>
         </form>
 
         <div className="text-center mt-4">
-          <a href="/login" style={{ color: 'var(--primary)' }}>已有账号？立即登录</a>
+          <span className="text-secondary">已有账号？</span>{' '}
+          <Link to="/login">立即登录</Link>
         </div>
       </div>
     </div>