/* Main CSS file with modern UI enhancements - Updated Theme */
:root {
  /* Enhanced Color Palette */
  --primary-color: #667eea;
  --primary-hover: #5a6fd8;
  --primary-light: rgba(102, 126, 234, 0.1);
  --secondary-color: #764ba2;
  --secondary-hover: #6a4190;
  --success-color: #28C76F;
  --success-hover: #1ea05a;
  --success-light: rgba(40, 199, 111, 0.1);
  --danger-color: #FF6B6B;
  --danger-hover: #ff5252;
  --danger-light: rgba(255, 107, 107, 0.1);
  --warning-color: #FFD93D;
  --warning-hover: #ffd000;
  --warning-light: rgba(255, 217, 61, 0.1);
  --info-color: #4facfe;
  --info-hover: #2196f3;
  --info-light: rgba(79, 172, 254, 0.1);
  --light-color: #f8f9fa;
  --dark-color: #2c3e50;
  --text-primary: #2c3e50;
  --text-secondary: #6c757d;
  --text-muted: #95a5a6;
  
  /* Enhanced Gradients */
  --primary-gradient: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  --secondary-gradient: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
  --accent-gradient: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
  --success-gradient: linear-gradient(135deg, #81FBB8 0%, #28C76F 100%);
  --warning-gradient: linear-gradient(135deg, #FFD93D 0%, #FF6B6B 100%);
  --dark-gradient: linear-gradient(135deg, #2c3e50 0%, #34495e 100%);
  
  /* Enhanced Backgrounds */
  --body-bg: #f5f7ff;
  --card-bg: rgba(255, 255, 255, 0.95);
  --glass-bg: rgba(255, 255, 255, 0.1);
  
  /* Enhanced Shadows */
  --shadow-sm: 0 2px 10px rgba(0, 0, 0, 0.08);
  --shadow-md: 0 8px 30px rgba(0, 0, 0, 0.12);
  --shadow-lg: 0 15px 50px rgba(0, 0, 0, 0.15);
  --shadow-xl: 0 25px 80px rgba(0, 0, 0, 0.2);
  --shadow-colored: 0 8px 30px rgba(102, 126, 234, 0.3);
  
  /* Enhanced Border Radius */
  --border-radius-sm: 12px;
  --border-radius-md: 16px;
  --border-radius-lg: 24px;
  --border-radius-xl: 32px;
  
  /* Enhanced Transitions */
  --transition-fast: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-normal: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: all 0.5s cubic-bezier(0.4, 0, 0.2, 1);
  
  --border-color: rgba(102, 126, 234, 0.1);
}

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
  line-height: 1.7;
  color: var(--text-primary);
  background: var(--body-bg);
  margin: 0;
  padding: 0;
  transition: background-color var(--transition-normal);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  font-weight: 400;
}

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

/* Enhanced Card Styling */
.card {
  background: var(--card-bg);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-radius: var(--border-radius-lg);
  box-shadow: var(--shadow-md);
  padding: 2rem;
  margin-bottom: 2rem;
  transition: var(--transition-normal);
  border: 1px solid rgba(255, 255, 255, 0.2);
  position: relative;
  overflow: hidden;
}

.card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--primary-gradient);
}

.card:hover {
  transform: translateY(-8px);
  box-shadow: var(--shadow-xl);
}

/* Enhanced Button Styling */
.button {
  display: inline-block;
  font-weight: 600;
  text-align: center;
  white-space: nowrap;
  vertical-align: middle;
  user-select: none;
  border: none;
  padding: 1rem 2rem;
  font-size: 1.1rem;
  line-height: 1.5;
  border-radius: var(--border-radius-md);
  transition: var(--transition-normal);
  cursor: pointer;
  position: relative;
  overflow: hidden;
  letter-spacing: 0.01em;
  text-decoration: none;
}

.button::before {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(255,255,255,0.2), transparent);
  transition: var(--transition-normal);
}

.button:hover::before {
  left: 100%;
}

.button::after {
  content: '';
  position: absolute;
  top: 50%;
  left: 50%;
  width: 5px;
  height: 5px;
  background: rgba(255, 255, 255, 0.5);
  opacity: 0;
  border-radius: 100%;
  transform: scale(1, 1) translate(-50%);
  transform-origin: 50% 50%;
}

.button:focus:not(:active)::after {
  animation: ripple 1s ease-out;
}

@keyframes ripple {
  0% {
    transform: scale(0, 0);
    opacity: 0.5;
  }
  20% {
    transform: scale(25, 25);
    opacity: 0.3;
  }
  100% {
    opacity: 0;
    transform: scale(40, 40);
  }
}

.button.primary {
  color: #fff;
  background: var(--primary-gradient);
  box-shadow: var(--shadow-md);
}

.button.primary:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-colored);
  filter: brightness(1.05);
}

.button.secondary {
  color: #fff;
  background: var(--dark-gradient);
  box-shadow: var(--shadow-md);
}

.button.secondary:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-lg);
}

.button.success {
  color: #fff;
  background: var(--success-gradient);
  box-shadow: var(--shadow-md);
}

.button.success:hover {
  transform: translateY(-3px);
  box-shadow: 0 8px 30px rgba(40, 199, 111, 0.3);
}

.button.danger {
  color: #fff;
  background: var(--warning-gradient);
  box-shadow: var(--shadow-md);
}

.button.danger:hover {
  transform: translateY(-3px);
  box-shadow: 0 8px 30px rgba(255, 107, 107, 0.3);
}

.button.small {
  padding: 0.75rem 1.5rem;
  font-size: 1rem;
}

.button.large {
  padding: 1.25rem 2.5rem;
  font-size: 1.2rem;
}

.button.full-width {
  display: block;
  width: 100%;
}

/* Enhanced Loading Spinner */
.spinner {
  display: inline-block;
  width: 1.5rem;
  height: 1.5rem;
  vertical-align: text-bottom;
  border: 0.2em solid rgba(102, 126, 234, 0.2);
  border-right-color: var(--primary-color);
  border-radius: 50%;
  animation: spinner-border 0.75s linear infinite;
}

.spinner.small {
  width: 1rem;
  height: 1rem;
  border-width: 0.15em;
}

@keyframes spinner-border {
  to { transform: rotate(360deg); }
}

/* Enhanced Loading Button State */
.button.loading {
  position: relative;
  color: transparent !important;
  pointer-events: none;
}

.button.loading::after {
  content: "";
  position: absolute;
  top: 50%;
  left: 50%;
  width: 24px;
  height: 24px;
  margin-top: -12px;
  margin-left: -12px;
  border: 3px solid rgba(255, 255, 255, 0.3);
  border-radius: 50%;
  border-top-color: #fff;
  animation: spinner-border 0.75s linear infinite;
}

/* Enhanced Form Styling */
.form-group {
  margin-bottom: 2rem;
  position: relative;
}

.form-group label {
  display: block;
  margin-bottom: 0.75rem;
  font-weight: 600;
  color: var(--text-primary);
  font-size: 1rem;
  letter-spacing: 0.01em;
}

.form-group input[type="text"],
.form-group input[type="email"],
.form-group input[type="password"],
.form-group input[type="number"],
.form-group input[type="date"],
.form-group input[type="tel"],
.form-group input[type="url"],
.form-group select,
.form-group textarea {
  display: block;
  width: 100%;
  padding: 1rem 1.25rem;
  font-size: 1.1rem;
  line-height: 1.5;
  color: var(--text-primary);
  background: rgba(255, 255, 255, 0.8);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  background-clip: padding-box;
  border: 2px solid var(--border-color);
  border-radius: var(--border-radius-md);
  transition: var(--transition-normal);
  font-weight: 500;
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
  border-color: var(--primary-color);
  outline: 0;
  box-shadow: 0 0 0 4px var(--primary-light);
  background: rgba(255, 255, 255, 1);
  transform: translateY(-2px);
}

/* Enhanced Table Styling */
.data-table {
  width: 100%;
  border-collapse: separate;
  border-spacing: 0;
  margin-bottom: 2rem;
  background: var(--card-bg);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-radius: var(--border-radius-lg);
  overflow: hidden;

  box-shadow: var(--shadow-md);
}

.data-table th,
.data-table td {
  padding: 1.5rem;
  vertical-align: top;
  border-top: 1px solid var(--border-color);
}

.data-table thead th {
  vertical-align: bottom;
  border-bottom: 2px solid var(--border-color);
  background: linear-gradient(135deg, var(--primary-light), rgba(118, 75, 162, 0.05));
  font-weight: 700;
  color: var(--text-primary);
  letter-spacing: 0.01em;
}

.data-table tbody tr {
  transition: var(--transition-fast);
}

.data-table tbody tr:hover {
  background: var(--primary-light);
  transform: scale(1.01);
}

/* Enhanced Status Badges */
.status-badge {
  display: inline-block;
  padding: 0.5em 1em;
  font-size: 0.85em;
  font-weight: 600;
  line-height: 1;
  text-align: center;
  white-space: nowrap;
  vertical-align: baseline;
  border-radius: var(--border-radius-xl);
  transition: var(--transition-fast);
  letter-spacing: 0.02em;
}

.status-paid {
  color: var(--success-color);
  background: var(--success-light);
  border: 1px solid rgba(40, 199, 111, 0.2);
}

.status-sent {
  color: var(--info-color);
  background: var(--info-light);
  border: 1px solid rgba(79, 172, 254, 0.2);
}

.status-draft {
  color: #e67e22;
  background: var(--warning-light);
  border: 1px solid rgba(255, 217, 61, 0.2);
}

.status-overdue {
  color: var(--danger-color);
  background: var(--danger-light);
  border: 1px solid rgba(255, 107, 107, 0.2);
}

.status-cancelled {
  color: var(--text-secondary);
  background: rgba(108, 117, 125, 0.1);
  border: 1px solid rgba(108, 117, 125, 0.2);
}

/* Enhanced Alert Messages */
.alert {
  position: relative;
  padding: 1.25rem 1.5rem;
  margin-bottom: 2rem;
  border: none;
  border-radius: var(--border-radius-md);
  font-weight: 500;
  font-size: 1rem;
  animation: slideIn 0.5s ease-out;
  overflow: hidden;
}

.alert::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  bottom: 0;
  width: 4px;
}

@keyframes slideIn {
  from {
    opacity: 0;
    transform: translateX(-20px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

.alert.success {
  color: var(--success-color);
  background: linear-gradient(135deg, var(--success-light), rgba(129, 251, 184, 0.05));
  box-shadow: var(--shadow-sm);
}

.alert.success::before {
  background: var(--success-gradient);
}

.alert.error {
  color: var(--danger-color);
  background: linear-gradient(135deg, var(--danger-light), rgba(245, 87, 108, 0.05));
  box-shadow: var(--shadow-sm);
}

.alert.error::before {
  background: var(--warning-gradient);
}

.alert.warning {
  color: #e67e22;
  background: linear-gradient(135deg, var(--warning-light), rgba(255, 107, 107, 0.05));
  box-shadow: var(--shadow-sm);
}

.alert.warning::before {
  background: var(--warning-gradient);
}

.alert.info {
  color: var(--info-color);
  background: linear-gradient(135deg, var(--info-light), rgba(0, 242, 254, 0.05));
  box-shadow: var(--shadow-sm);
}

.alert.info::before {
  background: var(--accent-gradient);
}

/* Enhanced Notification Toast */
.notification {
  position: fixed;
  bottom: 30px;
  right: 30px;
  padding: 1.25rem 1.5rem;
  background: var(--dark-gradient);
  color: white;
  border-radius: var(--border-radius-md);
  box-shadow: var(--shadow-xl);
  transform: translateY(100px);
  opacity: 0;
  transition: var(--transition-normal);
  z-index: 1000;
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border: 1px solid rgba(255, 255, 255, 0.1);
}

.notification.show {
  transform: translateY(0);
  opacity: 1;
}

/* Enhanced Page Transitions */
.page-transition {
  animation: fadeInUp 0.6s cubic-bezier(0.4, 0, 0.2, 1);
}

@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* Enhanced Header & Navigation */
header {
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  box-shadow: var(--shadow-sm);
  padding: 1.5rem 0;
  margin-bottom: 3rem;
  border-bottom: 1px solid rgba(255, 255, 255, 0.2);
  position: sticky;
  top: 0;
  z-index: 1000;
}

header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

header .logo {
  display: flex;
  align-items: center;
}

header .logo img {
  max-height: 50px;
  margin-right: 1rem;
}

header .logo h1 {
  margin: 0;
  font-size: 2.5rem;
  font-weight: 800;
  background: var(--primary-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  letter-spacing: -0.02em;
  transition: var(--transition-normal);
}

header .logo h1:hover {
  transform: scale(1.05);
  filter: brightness(1.1);
}

header nav ul {
  display: flex;
  list-style: none;
  margin: 0;
  padding: 0;
  gap: 2.5rem;
}

header nav li {
  margin: 0;
}

header nav a {
  color: var(--text-primary);
  text-decoration: none;
  font-weight: 600;
  font-size: 1.1rem;
  padding: 0.5rem 0;
  position: relative;
  transition: var(--transition-normal);
}

header nav a::after {
  content: '';
  position: absolute;
  width: 0;
  height: 3px;
  bottom: 0;
  left: 0;
  background: var(--primary-gradient);
  border-radius: 2px;
  transition: var(--transition-normal);
}

header nav a:hover {
  color: var(--primary-color);
  transform: translateY(-2px);
}

header nav a:hover::after {
  width: 100%;
}

header nav li.active a {
  color: var(--primary-color);
}

header nav li.active a::after {
  width: 100%;
}

/* Enhanced Page Header */
.page-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 3rem;
  padding: 2rem;
  background: var(--card-bg);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-radius: var(--border-radius-lg);
  box-shadow: var(--shadow-md);
  border: 1px solid rgba(255, 255, 255, 0.2);
  position: relative;
  overflow: hidden;
}

.page-header::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: var(--primary-gradient);
}

.page-header h1 {
  margin: 0;
  font-size: 2.5rem;
  color: var(--text-primary);
  font-weight: 700;
  letter-spacing: -0.02em;
}

/* Enhanced Stats Cards */
.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 2rem;
  margin-bottom: 3rem;
}

.stat-card {
  background: var(--card-bg);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-radius: var(--border-radius-lg);
  padding: 2rem;
  box-shadow: var(--shadow-md);
  transition: var(--transition-normal);
  border: 1px solid rgba(255, 255, 255, 0.2);
  position: relative;
  overflow: hidden;
}

.stat-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  bottom: 0;
  width: 4px;
  background: var(--primary-gradient);
}

.stat-card:hover {
  transform: translateY(-8px);
  box-shadow: var(--shadow-xl);
}

.stat-card h3 {
  margin-top: 0;
  margin-bottom: 1rem;
  color: var(--text-secondary);
  font-size: 1.1rem;
  font-weight: 600;
  letter-spacing: 0.01em;
}

.stat-card .stat-number {
  font-size: 2.5rem;
  font-weight: 700;
  color: var(--text-primary);
  margin: 0;
  letter-spacing: -0.02em;
}

/* Enhanced Modal */
.modal {
  display: none;
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.6);
  backdrop-filter: blur(5px);
  -webkit-backdrop-filter: blur(5px);
  z-index: 1000;
  overflow-y: auto;
  animation: fadeIn 0.3s ease;
}

.modal-content {
  background: var(--card-bg);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  margin: 5% auto;
  padding: 3rem;
  border-radius: var(--border-radius-lg);
  box-shadow: var(--shadow-xl);
  max-width: 600px;
  position: relative;
  animation: slideIn 0.3s ease;
  border: 1px solid rgba(255, 255, 255, 0.2);
}

@keyframes slideIn {
  from { transform: translateY(-50px); opacity: 0; }
  to { transform: translateY(0); opacity: 1; }
}

.modal .close {
  position: absolute;
  top: 1.5rem;
  right: 2rem;
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--text-secondary);
  cursor: pointer;
  transition: var(--transition-fast);
  width: 32px;
  height: 32px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  background: rgba(108, 117, 125, 0.1);
}

.modal .close:hover {
  color: var(--danger-color);
  background: var(--danger-light);
  transform: scale(1.1);
}

/* Enhanced Toggle Switch */
.toggle-switch {
  position: relative;
  display: inline-block;
  width: 60px;
  height: 34px;
}

.toggle-switch input {
  opacity: 0;
  width: 0;
  height: 0;
}

.toggle-switch label {
  position: absolute;
  cursor: pointer;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(108, 117, 125, 0.3);
  transition: var(--transition-normal);
  border-radius: 34px;
  box-shadow: inset 0 2px 4px rgba(0,0,0,0.1);
}

.toggle-switch label:before {
  position: absolute;
  content: "";
  height: 26px;
  width: 26px;
  left: 4px;
  bottom: 4px;
  background: white;
  transition: var(--transition-normal);
  border-radius: 50%;
  box-shadow: 0 2px 8px rgba(0,0,0,0.2);
}

.toggle-switch input:checked + label {
  background: var(--primary-gradient);
}

.toggle-switch input:focus + label {
  box-shadow: 0 0 0 3px var(--primary-light);
}

.toggle-switch input:checked + label:before {
  transform: translateX(26px);
}

/* Enhanced Responsive Design */
@media (max-width: 768px) {
  .container {
    padding: 0 15px;
  }
  
  header .logo h1 {
    font-size: 2rem;
  }
  
  .page-header {
    flex-direction: column;
    align-items: flex-start;
    padding: 1.5rem;
  }
  
  .page-header h1 {
    font-size: 2rem;
  }
  
  .page-header .actions {
    margin-top: 1.5rem;
  }
  
  .stats-grid {
    grid-template-columns: 1fr;
    gap: 1.5rem;
  }
  
  header .container {
    flex-direction: column;
    gap: 1.5rem;
  }
  
  header nav ul {
    gap: 1.5rem;
    flex-wrap: wrap;
    justify-content: center;
  }
  
  .card {
    padding: 1.5rem;
  }
  
  .modal-content {
    margin: 10% 15px;
    padding: 2rem;
  }
}

@media (max-width: 480px) {
  header .logo h1 {
    font-size: 1.8rem;
  }
  
  .page-header h1 {
    font-size: 1.8rem;
  }
  
  .button {
    padding: 1rem 1.5rem;
    font-size: 1rem;
  }
  
  .form-group input,
  .form-group select,
  .form-group textarea {
    padding: 1rem;
    font-size: 1rem;
  }
  
  .stat-card .stat-number {
    font-size: 2rem;
  }
  
  .card {
    padding: 1.25rem;
  }
}

/* Scroll Animations */
@media (prefers-reduced-motion: no-preference) {
  .card {
    animation: fadeInUp 0.6s ease-out;
  }
  
  .card:nth-child(2) { animation-delay: 0.1s; }
  .card:nth-child(3) { animation-delay: 0.2s; }
  .card:nth-child(4) { animation-delay: 0.3s; }
}

/* Focus Styles for Accessibility */
.button:focus,
.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
  outline: 3px solid var(--primary-light);
  outline-offset: 2px;
}

/* Print Styles */
@media print {
  .card {
    box-shadow: none;
    border: 1px solid #ddd;
    background: white;
  }
  
  .button {
    background: white !important;
    color: black !important;
    border: 1px solid black !important;
  }
  
  header {
    background: white;
    box-shadow: none;
  }
}