    <!DOCTYPE html>
    <html lang="en">
    <head>
      <meta charset="UTF-8">
      <title>AdminCP Login — Crypto Payment System</title>
      <meta name="viewport" content="width=device-width, initial-scale=1.0">
      <link href="https://fonts.googleapis.com/css2?family=Plus+Jakarta+Sans:wght@400;500;600;700;800&display=swap" rel="stylesheet">
      <style>
        :root {
          --bg: #09090e;
          --card: #131324;
          --border: #242442;
          --accent: #f7931a;
          --text: #f0f0f5;
          --muted: #8b8ba8;
          --red: #fc5c65;
        }
        * { box-sizing: border-box; margin: 0; padding: 0; }
        body {
          font-family: 'Plus Jakarta Sans', sans-serif;
          background: var(--bg);
          color: var(--text);
          display: flex;
          align-items: center;
          justify-content: center;
          min-height: 100vh;
          padding: 20px;
        }
        .login-box {
          background: var(--card);
          border: 1px solid var(--border);
          border-radius: 16px;
          width: 100%;
          max-width: 400px;
          padding: 40px 32px;
          box-shadow: 0 12px 40px rgba(0,0,0,0.6);
        }
        .header { text-align: center; margin-bottom: 32px; }
        .header h1 { font-size: 26px; font-weight: 800; }
        .header h1 span { color: var(--accent); }
        .header p { color: var(--muted); font-size: 14px; margin-top: 8px; }
        .form-group { margin-bottom: 20px; }
        .form-group label { display: block; font-size: 12px; font-weight: 600; color: var(--muted); margin-bottom: 8px; text-transform: uppercase; }
        .form-group input {
          width: 100%; background: #09090e; border: 1px solid var(--border);
          border-radius: 10px; padding: 12px 16px; color: #fff;
          font-size: 15px; outline: none; transition: 0.2s;
        }
        .form-group input:focus { border-color: var(--accent); }
        .btn-submit {
          width: 100%; padding: 14px; background: var(--accent); color: #000;
          border: none; border-radius: 10px; font-size: 16px; font-weight: 700;
          cursor: pointer; transition: 0.2s;
        }
        .btn-submit:hover { background: #ffa433; }
        .error {
          background: rgba(252, 92, 101, 0.1); border: 1px solid var(--red);
          color: var(--red); padding: 12px 16px; border-radius: 8px;
          font-size: 14px; margin-bottom: 20px; text-align: center;
        }
      </style>
    </head>
    <body>
      <div class="login-box">
        <div class="header">
          <h1>⚡ Admin<span>CP</span></h1>
          <p>Provide credentials to manage transactions</p>
        </div>
                <form method="POST">
          <div class="form-group">
            <label>Username</label>
            <input type="text" name="username" placeholder="admin" required autofocus>
          </div>
          <div class="form-group">
            <label>Password</label>
            <input type="password" name="password" placeholder="••••••••" required>
          </div>
          <button type="submit" name="login" class="btn-submit">Authenticate</button>
        </form>
      </div>
    </body>
    </html>
    