@import url('https://fonts.googleapis.com/css2?family=Poppins:wght@300;400;500;600;700&display=swap');
    
    :root {
      --primary: #2563eb;
      --accent: #8b5cf6;
      --dark: #1e293b;
      --light: #f8fafc;
      --success: #10b981;
      --error: #ef4444;
      --warning: #f59e0b;
    }
    
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
      font-family: 'Poppins', sans-serif;
    }
    
    body {
      min-height: 100vh;
      display: flex;
      align-items: center;
      justify-content: center;
      padding: 20px;
    }
    
    .container {
      width: 100%;
      max-width: 440px;
      background: white;
      border-radius: 16px;
      overflow: hidden;
      box-shadow: 0 20px 40px rgba(0, 0, 0, 0.15);
    }
    
    .header {
      background: linear-gradient(135deg, var(--primary) 0%, var(--accent) 100%);
      padding: 28px;
      text-align: center;
      position: relative;
    }
    
    .header::after {
      content: '';
      position: absolute;
      bottom: -20px;
      left: 50%;
      transform: translateX(-50%);
      width: 40px;
      height: 40px;
      background: white;
      border-radius: 50%;
    }
    
    .header h1 {
      color: white;
      font-size: 28px;
      font-weight: 700;
      margin-bottom: 8px;
      letter-spacing: 0.5px;
    }
    
    .header p {
      color: rgba(255, 255, 255, 0.9);
      font-size: 15px;
      font-weight: 400;
    }
    
    .form-container {
      padding: 32px;
    }
    
    .alert {
      padding: 14px 18px;
      border-radius: 12px;
      margin-bottom: 24px;
      display: flex;
      align-items: flex-start;
      font-size: 14px;
      line-height: 1.5;
    }
    
    .alert-error {
      background-color: #fee2e2;
      color: #b91c1c;
      border: 1px solid #fecaca;
    }
    
    .alert-warning {
      background-color: #fffbeb;
      color: #92400e;
      border: 1px solid #fde68a;
    }
    
    .alert-icon {
      margin-right: 12px;
      font-size: 18px;
      margin-top: 2px;
    }
    
    .referrer-section {
      text-align: center;
      margin-bottom: 28px;
      padding: 20px;
      background: linear-gradient(135deg, #f8fafc 0%, #f1f5f9 100%);
      border-radius: 14px;
      border: 1px solid #e2e8f0;
    }
    
    .referrer-icon {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      width: 60px;
      height: 60px;
      border-radius: 50%;
      background: linear-gradient(135deg, var(--primary) 0%, var(--accent) 100%);
      color: white;
      font-size: 24px;
      margin-bottom: 12px;
    }
    
    .referrer-label {
      font-size: 14px;
      color: #64748b;
      font-weight: 500;
      margin-bottom: 6px;
    }
    
    .referrer-name {
      font-size: 20px;
      font-weight: 600;
      color: var(--dark);
    }
    
    .form-group {
      margin-bottom: 20px;
    }
    
    .input-group {
      position: relative;
    }
    
    .input-icon {
      position: absolute;
      left: 16px;
      top: 50%;
      transform: translateY(-50%);
      color: #94a3b8;
      font-size: 18px;
      z-index: 1;
    }
    
    input[type="text"],
    input[type="email"],
    input[type="password"] {
      width: 100%;
      padding: 16px 16px 16px 50px;
      border: 1px solid #d1d5db;
      border-radius: 12px;
      font-size: 16px;
      transition: all 0.3s;
      background: #f8fafc;
      color: var(--dark);
    }
    
    input[type="text"]:focus,
    input[type="email"]:focus,
    input[type="password"]:focus {
      outline: none;
      border-color: var(--primary);
      box-shadow: 0 0 0 4px rgba(37, 99, 235, 0.15);
      background: white;
    }
    
    .password-toggle {
      position: absolute;
      right: 16px;
      top: 50%;
      transform: translateY(-50%);
      color: #94a3b8;
      cursor: pointer;
      font-size: 18px;
      background: none;
      border: none;
      z-index: 2;
    }
    
    .btn {
      width: 100%;
      padding: 16px;
      background: linear-gradient(135deg, var(--primary) 0%, var(--accent) 100%);
      border: none;
      border-radius: 12px;
      color: white;
      font-size: 16px;
      font-weight: 600;
      cursor: pointer;
      transition: all 0.3s;
      box-shadow: 0 4px 6px rgba(37, 99, 235, 0.2);
      letter-spacing: 0.5px;
    }
    
    .btn:hover {
      opacity: 0.95;
      transform: translateY(-2px);
      box-shadow: 0 8px 15px rgba(37, 99, 235, 0.3);
    }
    
    .btn:active {
      transform: translateY(0);
    }
    
    .login-link {
      text-align: center;
      margin-top: 28px;
      font-size: 15px;
      color: #64748b;
    }
    
    .login-link a {
      color: var(--primary);
      text-decoration: none;
      font-weight: 500;
      transition: all 0.2s;
    }
    
    .login-link a:hover {
      text-decoration: underline;
      color: var(--accent);
    }
    
    @media (max-width: 480px) {
      .container {
        border-radius: 14px;
      }
      
      .header {
        padding: 24px;
      }
      
      .header h1 {
        font-size: 24px;
      }
      
      .form-container {
        padding: 24px;
      }
      
      input[type="text"],
      input[type="email"],
      input[type="password"] {
        padding: 14px 14px 14px 46px;
      }
    }