/* Modern CSS Variables for theming */
:root {
  --primary-color: #6366f1;
  --primary-dark: #4f46e5;
  --primary-light: #8b85ff;
  --secondary-color: #06b6d4;
  --success-color: #10b981;
  --warning-color: #f59e0b;
  --danger-color: #ef4444;
  --info-color: #3b82f6;
  
  --bg-primary: #f8fafc;
  --bg-secondary: #ffffff;
  --bg-tertiary: #f1f5f9;
  --bg-gradient: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  
  --text-primary: #1e293b;
  --text-secondary: #64748b;
  --text-muted: #94a3b8;
  --text-inverse: #ffffff;
  
  --border-color: #e2e8f0;
  --border-focus: #6366f1;
  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
  --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
  --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
  --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);
  
  --radius-sm: 6px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --radius-xl: 16px;
  
  --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-fast: all 0.15s cubic-bezier(0.4, 0, 0.2, 1);
}

/* Dark theme variables */
[data-theme="dark"] {
  --bg-primary: #0f172a;
  --bg-secondary: #1e293b;
  --bg-tertiary: #334155;
  --bg-gradient: linear-gradient(135deg, #1e293b 0%, #334155 100%);
  
  --text-primary: #f1f5f9;
  --text-secondary: #cbd5e1;
  --text-muted: #94a3b8;
  
  --border-color: #334155;
  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.3);
  --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.3), 0 2px 4px -2px rgb(0 0 0 / 0.3);
  --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.3), 0 4px 6px -4px rgb(0 0 0 / 0.3);
  --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.3), 0 8px 10px -6px rgb(0 0 0 / 0.3);
}

/* Reset and base styles */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-family);
  background: var(--bg-gradient);
  min-height: 100vh;
  color: var(--text-primary);
  line-height: 1.6;
  transition: var(--transition);
  overflow-x: hidden;
}

/* Utility classes */
.container {
  max-width: 1400px;
  margin: 0 auto;
  padding: 1.5rem;
}

.section-header {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 1.5rem;
  padding-bottom: 0.75rem;
  border-bottom: 2px solid var(--primary-color);
}

.section-header i {
  font-size: 1.25rem;
  color: var(--primary-color);
}

.section-header h2,
.section-header h3 {
  color: var(--text-primary);
  font-weight: 600;
  margin: 0;
}

/* Header styles */
header {
  background: var(--bg-secondary);
  border-radius: var(--radius-xl);
  padding: 2rem;
  margin-bottom: 2rem;
  box-shadow: var(--shadow-xl);
  backdrop-filter: blur(10px);
  border: 1px solid var(--border-color);
  animation: slideInDown 0.6s ease-out;
}

.header-content {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 2rem;
}

.logo-section {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.logo-section i {
  font-size: 2.5rem;
  color: var(--primary-color);
  background: linear-gradient(135deg, var(--primary-color), var(--primary-light));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.logo-section h1 {
  font-size: 2.5rem;
  font-weight: 700;
  background: linear-gradient(135deg, var(--primary-color), var(--primary-light));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin: 0;
}

.theme-toggle {
  position: relative;
}

.theme-btn {
  background: var(--bg-tertiary);
  border: 1px solid var(--border-color);
  border-radius: 50%;
  width: 3rem;
  height: 3rem;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: var(--transition);
  color: var(--text-secondary);
}

.theme-btn:hover {
  background: var(--primary-color);
  color: var(--text-inverse);
  transform: rotate(180deg);
  box-shadow: var(--shadow-md);
}

/* Balance cards */
.balance-info {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 1.5rem;
}

.balance-card {
  background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
  color: var(--text-inverse);
  padding: 2rem;
  border-radius: var(--radius-lg);
  display: flex;
  align-items: center;
  gap: 1.5rem;
  box-shadow: var(--shadow-lg);
  transition: var(--transition);
  border: 1px solid rgba(255, 255, 255, 0.1);
  position: relative;
  overflow: hidden;
}

.balance-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.1), transparent);
  transition: left 0.6s;
}

.balance-card:hover::before {
  left: 100%;
}

.balance-card:hover {
  transform: translateY(-8px) scale(1.02);
  box-shadow: var(--shadow-xl);
}

.balance-card.income {
  background: linear-gradient(135deg, var(--success-color), #059669);
}

.balance-card.expense {
  background: linear-gradient(135deg, var(--danger-color), #dc2626);
}

.card-icon {
  background: rgba(255, 255, 255, 0.2);
  border-radius: var(--radius-md);
  padding: 1rem;
  display: flex;
  align-items: center;
  justify-content: center;
}

.card-icon i {
  font-size: 1.75rem;
}

.card-content h3 {
  font-size: 0.9rem;
  font-weight: 500;
  opacity: 0.9;
  margin-bottom: 0.5rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.card-content span {
  font-size: 2rem;
  font-weight: 700;
  display: block;
}

/* Main layout */
main {
  display: grid;
  grid-template-columns: minmax(320px, 400px) 1fr;
  gap: 2rem;
  align-items: start;
}

/* Input section */
.input-section {
  background: var(--bg-secondary);
  padding: 2rem;
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-lg);
  height: fit-content;
  border: 1px solid var(--border-color);
  animation: slideInLeft 0.6s ease-out 0.2s both;
}

/* Form styles */
.form-group {
  margin-bottom: 1.5rem;
}

.form-group label {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  margin-bottom: 0.75rem;
  font-weight: 600;
  color: var(--text-primary);
  font-size: 0.875rem;
  text-transform: uppercase;
  letter-spacing: 0.025em;
}

.form-group label i {
  color: var(--primary-color);
  font-size: 0.875rem;
}

.form-group input,
.form-group select {
  width: 100%;
  padding: 1rem;
  border: 2px solid var(--border-color);
  border-radius: var(--radius-md);
  font-size: 1rem;
  font-family: inherit;
  background: var(--bg-secondary);
  color: var(--text-primary);
  transition: var(--transition);
}

.form-group input:focus,
.form-group select:focus {
  outline: none;
  border-color: var(--border-focus);
  box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
  transform: translateY(-2px);
}

.form-group input::placeholder {
  color: var(--text-muted);
}

/* Button styles */
.btn-primary,
.btn-secondary {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 1rem 2rem;
  border: none;
  border-radius: var(--radius-md);
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition);
  text-transform: uppercase;
  letter-spacing: 0.025em;
  width: 100%;
}

.btn-primary {
  background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
  color: var(--text-inverse);
  box-shadow: var(--shadow-md);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
  background: linear-gradient(135deg, var(--primary-dark), var(--primary-color));
}

.btn-secondary {
  background: var(--bg-tertiary);
  color: var(--text-primary);
  border: 1px solid var(--border-color);
  width: auto;
  padding: 0.75rem 1.5rem;
}

.btn-secondary:hover {
  background: var(--primary-color);
  color: var(--text-inverse);
  border-color: var(--primary-color);
  transform: translateY(-2px);
}

/* Dashboard */
.dashboard {
  display: flex;
  flex-direction: column;
  gap: 2rem;
  animation: slideInRight 0.6s ease-out 0.4s both;
}

.charts-section {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.5rem;
}

.chart-container {
  background: var(--bg-secondary);
  padding: 2rem;
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-lg);
  border: 1px solid var(--border-color);
  transition: var(--transition);
}

.chart-container:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-xl);
}

.chart-container canvas {
  max-height: 300px;
}

/* Budget section */
.budget-section {
  background: var(--bg-secondary);
  padding: 2rem;
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-lg);
  border: 1px solid var(--border-color);
}

.budget-form {
  display: grid;
  grid-template-columns: 1fr 1fr auto;
  gap: 1rem;
  margin-top: 1.5rem;
}

.budget-form input {
  padding: 0.75rem;
  border: 2px solid var(--border-color);
  border-radius: var(--radius-md);
  background: var(--bg-secondary);
  color: var(--text-primary);
  transition: var(--transition);
}

.budget-form input:focus {
  outline: none;
  border-color: var(--border-focus);
  box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

.budget-item {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1.5rem;
  margin-bottom: 1rem;
  background: var(--bg-tertiary);
  border-radius: var(--radius-lg);
  border-left: 4px solid var(--primary-color);
  transition: var(--transition);
}

.budget-item:hover {
  transform: translateX(8px);
  box-shadow: var(--shadow-md);
}

.budget-progress {
  width: 100%;
  height: 8px;
  background: var(--bg-primary);
  border-radius: 4px;
  margin-top: 0.75rem;
  overflow: hidden;
}

.budget-progress-bar {
  height: 100%;
  background: linear-gradient(90deg, var(--success-color), #059669);
  transition: width 0.6s ease-in-out;
  border-radius: 4px;
}

.budget-progress-bar.over {
  background: linear-gradient(90deg, var(--danger-color), #dc2626);
}

/* Transactions section */
.transactions-section {
  grid-column: 1 / -1;
  background: var(--bg-secondary);
  padding: 2rem;
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-lg);
  margin-top: 2rem;
  border: 1px solid var(--border-color);
  animation: slideInUp 0.6s ease-out 0.6s both;
}

.transaction-filters {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 1rem;
  margin-bottom: 2rem;
}

.filter-group {
  position: relative;
  display: flex;
  align-items: center;
}

.filter-group i {
  position: absolute;
  left: 1rem;
  color: var(--text-muted);
  z-index: 1;
  pointer-events: none;
}

.filter-group select,
.filter-group input {
  width: 100%;
  padding: 0.75rem 1rem 0.75rem 3rem;
  border: 2px solid var(--border-color);
  border-radius: var(--radius-md);
  background: var(--bg-secondary);
  color: var(--text-primary);
  transition: var(--transition);
}

.filter-group select:focus,
.filter-group input:focus {
  outline: none;
  border-color: var(--border-focus);
  box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

.transaction-item {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1.5rem;
  margin-bottom: 1rem;
  background: var(--bg-tertiary);
  border-radius: var(--radius-lg);
  border-left: 4px solid var(--primary-color);
  transition: var(--transition);
  animation: fadeInUp 0.3s ease-out;
}

.transaction-item:hover {
  transform: translateX(8px);
  box-shadow: var(--shadow-md);
}

.transaction-item.income {
  border-left-color: var(--success-color);
}

.transaction-item.expense {
  border-left-color: var(--danger-color);
}

.transaction-details {
  flex: 1;
}

.transaction-details h4 {
  margin-bottom: 0.5rem;
  color: var(--text-primary);
  font-weight: 600;
}

.transaction-details p {
  color: var(--text-secondary);
  font-size: 0.875rem;
}

.transaction-amount {
  font-size: 1.25rem;
  font-weight: 700;
  margin-right: 1rem;
}

.transaction-amount.income {
  color: var(--success-color);
}

.transaction-amount.expense {
  color: var(--danger-color);
}

.delete-btn {
  background: var(--danger-color);
  color: var(--text-inverse);
  border: none;
  padding: 0.5rem 1rem;
  border-radius: var(--radius-md);
  cursor: pointer;
  font-size: 0.875rem;
  font-weight: 600;
  transition: var(--transition);
  text-transform: uppercase;
  letter-spacing: 0.025em;
}

.delete-btn:hover {
  background: #dc2626;
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

/* Animations */
@keyframes slideInDown {
  from {
    opacity: 0;
    transform: translate3d(0, -100px, 0);
  }
  to {
    opacity: 1;
    transform: translate3d(0, 0, 0);
  }
}

@keyframes slideInLeft {
  from {
    opacity: 0;
    transform: translate3d(-100px, 0, 0);
  }
  to {
    opacity: 1;
    transform: translate3d(0, 0, 0);
  }
}

@keyframes slideInRight {
  from {
    opacity: 0;
    transform: translate3d(100px, 0, 0);
  }
  to {
    opacity: 1;
    transform: translate3d(0, 0, 0);
  }
}

@keyframes slideInUp {
  from {
    opacity: 0;
    transform: translate3d(0, 100px, 0);
  }
  to {
    opacity: 1;
    transform: translate3d(0, 0, 0);
  }
}

@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translate3d(0, 30px, 0);
  }
  to {
    opacity: 1;
    transform: translate3d(0, 0, 0);
  }
}

/* Responsive design */
@media (max-width: 1200px) {
  main {
    grid-template-columns: minmax(300px, 350px) 1fr;
    gap: 1.5rem;
  }
}

@media (max-width: 1024px) {
  main {
    grid-template-columns: 1fr;
    gap: 1.5rem;
  }
  
  .charts-section {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 768px) {
  .container {
    padding: 1rem;
  }
  
  header {
    padding: 1.5rem;
  }
  
  .header-content {
    flex-direction: column;
    gap: 1rem;
    text-align: center;
  }
  
  .logo-section h1 {
    font-size: 2rem;
  }
  
  .balance-info {
    grid-template-columns: 1fr;
  }
  
  .balance-card {
    padding: 1.5rem;
  }
  
  .budget-form {
    grid-template-columns: 1fr;
    gap: 0.75rem;
  }
  
  .transaction-filters {
    grid-template-columns: 1fr;
    gap: 0.75rem;
  }
  
  .transaction-item {
    flex-direction: column;
    align-items: flex-start;
    gap: 1rem;
  }
  
  .transaction-item > div:last-child {
    display: flex;
    align-items: center;
    gap: 1rem;
    width: 100%;
    justify-content: space-between;
  }
}

@media (max-width: 480px) {
  .container {
    padding: 0.75rem;
  }
  
  header {
    padding: 1.25rem;
  }
  
  .logo-section i {
    font-size: 2rem;
  }
  
  .logo-section h1 {
    font-size: 1.75rem;
  }
  
  .card-content span {
    font-size: 1.5rem;
  }
  
  .input-section,
  .chart-container,
  .budget-section,
  .transactions-section {
    padding: 1.25rem;
  }
  
  .balance-info {
    gap: 1rem;
  }
  
  .balance-card {
    padding: 1.25rem;
  }
  
  .form-group input,
  .form-group select {
    padding: 0.875rem;
  }
  
  .btn-primary {
    padding: 0.875rem 1.5rem;
  }
}

/* Loading states and micro-interactions */
.loading {
  position: relative;
  overflow: hidden;
}

.loading::after {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.2), transparent);
  animation: shimmer 1.5s infinite;
}

@keyframes shimmer {
  to {
    left: 100%;
  }
}

/* Scrollbar styling */
::-webkit-scrollbar {
  width: 8px;
}

::-webkit-scrollbar-track {
  background: var(--bg-tertiary);
}

::-webkit-scrollbar-thumb {
  background: var(--primary-color);
  border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--primary-dark);
}

/* Focus visible for accessibility */
*:focus-visible {
  outline: 2px solid var(--primary-color);
  outline-offset: 2px;
}

/* Fallback chart styles */
.fallback-chart {
  padding: 1rem;
  height: 200px;
  display: flex;
  flex-direction: column;
  justify-content: center;
}

.chart-placeholder {
  text-align: center;
  color: var(--text-muted);
  font-style: italic;
  padding: 2rem;
}

/* Fallback category chart */
.fallback-category-legend {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.fallback-category-item {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
}

.category-info {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.875rem;
}

.category-name {
  font-weight: 500;
  color: var(--text-primary);
}

.category-amount {
  color: var(--text-secondary);
  font-size: 0.8rem;
}

.category-bar {
  height: 8px;
  background-color: var(--bg-tertiary);
  border-radius: var(--radius-sm);
  overflow: hidden;
}

.category-bar-fill {
  height: 100%;
  border-radius: var(--radius-sm);
  transition: var(--transition);
}

/* Fallback trend chart */
.fallback-trend-chart {
  height: 100%;
  display: flex;
  flex-direction: column;
}

.trend-legend {
  display: flex;
  gap: 1rem;
  margin-bottom: 1rem;
  justify-content: center;
}

.legend-item {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.875rem;
  color: var(--text-secondary);
}

.legend-color {
  width: 12px;
  height: 12px;
  border-radius: 2px;
}

.income-color {
  background-color: #2ecc71;
}

.expense-color {
  background-color: #e74c3c;
}

.trend-container {
  flex: 1;
  display: flex;
  align-items: end;
  gap: 1rem;
  padding: 0 1rem;
  border-bottom: 1px solid var(--border-color);
  border-left: 1px solid var(--border-color);
}

.trend-month {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.5rem;
}

.trend-bars {
  height: 100px;
  display: flex;
  align-items: end;
  gap: 2px;
  width: 100%;
  justify-content: center;
}

.trend-bar {
  width: 12px;
  min-height: 2px;
  border-radius: 2px 2px 0 0;
  transition: var(--transition);
}

.income-bar {
  background-color: #2ecc71;
}

.expense-bar {
  background-color: #e74c3c;
}

.trend-label {
  font-size: 0.75rem;
  color: var(--text-muted);
  text-align: center;
}

.trend-bar:hover {
  opacity: 0.8;
  transform: scaleY(1.1);
}