:root {
  --primary-color: #3b82f6;
  --secondary-color: #1e40af;
  --success-color: #10b981;
  --warning-color: #f59e0b;
  --error-color: #ef4444;
  --info-color: #06b6d4;
  --gray-100: #f3f4f6;
  --gray-200: #e5e7eb;
  --gray-300: #d1d5db;
  --gray-400: #9ca3af;
  --gray-500: #6b7280;
  --gray-600: #4b5563;
  --gray-700: #374151;
  --gray-800: #1f2937;
  --gray-900: #111827;
  --border-radius: 12px;
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  min-height: 100vh;
  color: var(--gray-800);
  line-height: 1.6;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 20px;
}

.header {
  text-align: center;
  color: white;
  margin-bottom: 40px;
  padding: 40px 20px;
}

.logo {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 15px;
  margin-bottom: 15px;
}

.logo i {
  font-size: 3rem;
  color: #fbbf24;
}

.logo h1 {
  font-size: 3rem;
  font-weight: 700;
  margin: 0;
}

.subtitle {
  font-size: 1.25rem;
  opacity: 0.9;
  font-weight: 400;
  margin-bottom: 10px;
}

.main-content {
  background: white;
  border-radius: var(--border-radius);
  padding: 40px;
  box-shadow: var(--shadow-lg);
  margin-bottom: 30px;
}

.email-section {
  margin-bottom: 40px;
}

.email-input-container {
  display: flex;
  gap: 12px;
  margin-bottom: 25px;
  flex-wrap: wrap;
}

#currentEmail {
  flex: 1;
  min-width: 300px;
  padding: 16px 20px;
  border: 2px solid var(--gray-200);
  border-radius: var(--border-radius);
  font-size: 1.1rem;
  font-family: 'Courier New', monospace;
  background: var(--gray-100);
  color: var(--gray-800);
  transition: all 0.3s ease;
}

#currentEmail:focus {
  outline: none;
  border-color: var(--primary-color);
  background: white;
  box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1);
}

.btn {
  padding: 16px 24px;
  border: none;
  border-radius: var(--border-radius);
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.3s ease;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  text-decoration: none;
  white-space: nowrap;
}

.btn:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.btn:active {
  transform: translateY(0);
}

.btn:disabled {
  cursor: not-allowed;
  opacity: 0.6;
  transform: none;
}

.btn-primary {
  background: var(--primary-color);
  color: white;
}

.btn-primary:hover {
  background: var(--secondary-color);
}

.btn-success {
  background: var(--success-color);
  color: white;
}

.btn-success:hover {
  background: #059669;
}

.btn-info {
  background: var(--info-color);
  color: white;
}

.btn-info:hover {
  background: #0891b2;
}

.btn-warning {
  background: var(--warning-color);
  color: white;
}

.btn-warning:hover {
  background: #d97706;
}

.inbox-section {
  margin-top: 40px;
}

.ad-space {
  background: var(--gray-100);
  border: 2px dashed var(--gray-300);
  border-radius: var(--border-radius);
  padding: 20px;
  text-align: center;
  color: var(--gray-500);
  margin-bottom: 30px;
  min-height: 120px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.9rem;
}

.notification {
  position: fixed;
  top: 20px;
  right: 20px;
  padding: 16px 24px;
  border-radius: var(--border-radius);
  color: white;
  font-weight: 500;
  z-index: 1000;
  transform: translateX(400px);
  transition: transform 0.3s ease;
  max-width: 400px;
  box-shadow: var(--shadow-lg);
}

.notification.show {
  transform: translateX(0);
}

.notification.success {
  background: var(--success-color);
}

.notification.error {
  background: var(--error-color);
}

.notification.info {
  background: var(--info-color);
}

.notification.warning {
  background: var(--warning-color);
}

@media (max-width: 768px) {
  .container {
    padding: 15px;
  }
  
  .header {
    padding: 30px 15px;
  }
  
  .logo h1 {
    font-size: 2.5rem;
  }
  
  .logo i {
    font-size: 2.5rem;
  }
  
  .main-content {
    padding: 25px;
  }
  
  .email-input-container {
    flex-direction: column;
  }
  
  #currentEmail {
    min-width: auto;
  }
  
  .btn {
    padding: 14px 20px;
    justify-content: center;
  }
  
  .notification {
    right: 15px;
    left: 15px;
    max-width: none;
    transform: translateY(-100px);
  }
  
  .notification.show {
    transform: translateY(0);
  }
}