/* ===============================================
   VARIABLES CSS Y CONFIGURACIÓN GENERAL
   =============================================== */

:root {
  /* Colores modo claro */
  --primary-color: #4f46e5;
  --primary-hover: #3730a3;
  --secondary-color: #6b7280;
  --accent-color: #10b981;
  --warning-color: #f59e0b;
  --error-color: #ef4444;
  --success-color: #22c55e;
  
  /* Backgrounds modo claro */
  --bg-primary: #ffffff;
  --bg-secondary: #f8fafc;
  --bg-tertiary: #f1f5f9;
  --bg-card: #ffffff;
  --bg-overlay: rgba(0, 0, 0, 0.1);
  
  /* Textos modo claro */
  --text-primary: #1e293b;
  --text-secondary: #475569;
  --text-muted: #64748b;
  --text-inverse: #ffffff;
  
  /* Borders y shadows */
  --border-color: #e2e8f0;
  --border-focus: #4f46e5;
  --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);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
  
  /* Spacing y sizing */
  --spacing-xs: 0.25rem;
  --spacing-sm: 0.5rem;
  --spacing-md: 1rem;
  --spacing-lg: 1.5rem;
  --spacing-xl: 2rem;
  --spacing-2xl: 3rem;
  
  --radius-sm: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  
  /* Transiciones */
  --transition-fast: 0.15s ease-in-out;
  --transition-normal: 0.3s ease-in-out;
  --transition-slow: 0.5s ease-in-out;
}

/* Modo oscuro */
[data-theme="dark"], .dark-theme {
  --bg-primary: #0f172a;
  --bg-secondary: #1e293b;
  --bg-tertiary: #334155;
  --bg-card: #1e293b;
  --bg-overlay: rgba(0, 0, 0, 0.3);
  
  --text-primary: #f8fafc;
  --text-secondary: #cbd5e1;
  --text-muted: #94a3b8;
  
  --border-color: #334155;
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.3), 0 2px 4px -1px rgba(0, 0, 0, 0.2);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.3), 0 4px 6px -2px rgba(0, 0, 0, 0.2);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.3), 0 10px 10px -5px rgba(0, 0, 0, 0.2);
}

/* ===============================================
   RESET Y BASE STYLES
   =============================================== */

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

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
  line-height: 1.6;
  color: var(--text-primary);
  background: linear-gradient(135deg, var(--bg-secondary) 0%, var(--bg-tertiary) 100%);
  min-height: 100vh;
  transition: background var(--transition-normal), color var(--transition-normal);
}

/* ===============================================
   LAYOUT PRINCIPAL
   =============================================== */

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: var(--spacing-md);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* ===============================================
   HEADER
   =============================================== */

.header {
  background: var(--bg-card);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-lg);
  margin-bottom: var(--spacing-xl);
  border: 1px solid var(--border-color);
  transition: all var(--transition-normal);
}

.header-content {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: var(--spacing-lg) var(--spacing-xl);
}

.header-title {
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
}

.header-title i {
  font-size: 2rem;
  color: var(--primary-color);
  background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.header-title h1 {
  font-size: 2rem;
  font-weight: 700;
  background: linear-gradient(135deg, var(--text-primary), var(--text-secondary));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.theme-toggle {
  background: var(--bg-tertiary);
  border: 2px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: var(--spacing-sm) var(--spacing-md);
  cursor: pointer;
  transition: all var(--transition-fast);
  color: var(--text-primary);
  font-size: 1.2rem;
}

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

/* ===============================================
   MAIN CONTENT
   =============================================== */

.main-content {
  flex: 1;
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--spacing-xl);
}

@media (min-width: 1024px) {
  .main-content {
    grid-template-columns: 1fr 1fr;
  }
}

/* ===============================================
   CALCULATOR SECTION
   =============================================== */

.calculator-card, .results-card {
  background: var(--bg-card);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-xl);
  border: 1px solid var(--border-color);
  overflow: hidden;
  transition: all var(--transition-normal);
}

.calculator-card:hover, .results-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-xl);
}

.section-title {
  background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
  color: var(--text-inverse);
  padding: var(--spacing-lg) var(--spacing-xl);
  margin: 0;
  font-size: 1.5rem;
  font-weight: 600;
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
}

.section-title i {
  font-size: 1.3rem;
}

/* ===============================================
   FORMULARIO
   =============================================== */

.calculator-form {
  padding: var(--spacing-xl);
}

.form-row {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--spacing-lg);
  margin-bottom: var(--spacing-lg);
}

@media (min-width: 768px) {
  .form-row {
    grid-template-columns: 1fr 1fr;
  }
}

.form-group {
  position: relative;
}

.form-group label {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: var(--spacing-sm);
  font-size: 0.95rem;
}

.form-group label i {
  color: var(--primary-color);
  width: 1.2rem;
  text-align: center;
}

.optional {
  font-weight: 400;
  color: var(--text-muted);
  font-size: 0.85rem;
}

.form-group input {
  width: 100%;
  padding: var(--spacing-md) var(--spacing-lg);
  padding-right: 3rem;
  border: 2px solid var(--border-color);
  border-radius: var(--radius-lg);
  font-size: 1rem;
  background: var(--bg-secondary);
  color: var(--text-primary);
  transition: all var(--transition-fast);
  outline: none;
}

.form-group input:focus {
  border-color: var(--border-focus);
  background: var(--bg-primary);
  box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.1);
  transform: translateY(-1px);
}

.form-group input:invalid:not(:placeholder-shown) {
  border-color: var(--error-color);
}

.currency-suffix {
  position: absolute;
  right: var(--spacing-md);
  top: 50%;
  transform: translateY(-50%);
  color: var(--text-muted);
  font-weight: 600;
  pointer-events: none;
  margin-top: 1.5rem;
}

.error-message {
  color: var(--error-color);
  font-size: 0.85rem;
  margin-top: var(--spacing-xs);
  min-height: 1.2rem;
  opacity: 0;
  transition: opacity var(--transition-fast);
}

.error-message.show {
  opacity: 1;
}

/* ===============================================
   BOTONES
   =============================================== */

.form-actions {
  display: flex;
  gap: var(--spacing-md);
  margin-top: var(--spacing-xl);
  flex-wrap: wrap;
}

.btn {
  padding: var(--spacing-md) var(--spacing-xl);
  border: none;
  border-radius: var(--radius-lg);
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition-fast);
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  text-decoration: none;
  outline: none;
  position: relative;
  overflow: hidden;
  flex: 1;
  justify-content: center;
  min-width: 150px;
}

.btn::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: left var(--transition-normal);
}

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

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

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

.btn-secondary {
  background: var(--bg-tertiary);
  color: var(--text-primary);
  border: 2px solid var(--border-color);
}

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

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

/* ===============================================
   SECCIÓN DE RESULTADOS
   =============================================== */

.results-section {
  animation: slideInUp var(--transition-slow) ease-out;
}

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

.results-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--spacing-md);
  padding: var(--spacing-xl);
}

@media (min-width: 640px) {
  .results-grid {
    grid-template-columns: 1fr 1fr;
  }
}

.result-item {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: var(--spacing-lg);
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
  transition: all var(--transition-fast);
  position: relative;
  overflow: hidden;
}

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

.result-item.highlight {
  background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
  color: var(--text-inverse);
  border-color: transparent;
}

.result-item.highlight .result-icon {
  background: rgba(255, 255, 255, 0.2);
  color: var(--text-inverse);
}

.result-icon {
  background: var(--primary-color);
  color: var(--text-inverse);
  width: 3rem;
  height: 3rem;
  border-radius: var(--radius-lg);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
  flex-shrink: 0;
}

.result-content h3 {
  font-size: 0.9rem;
  font-weight: 600;
  margin-bottom: var(--spacing-xs);
  opacity: 0.9;
}

.result-value {
  font-size: 1.5rem;
  font-weight: 700;
  margin: 0;
}

/* ===============================================
   DESGLOSE DETALLADO
   =============================================== */

.breakdown-section {
  padding: 0 var(--spacing-xl) var(--spacing-xl);
}

.breakdown-title {
  font-size: 1.2rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: var(--spacing-lg);
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
}

.breakdown-title i {
  color: var(--primary-color);
}

.breakdown-grid {
  display: grid;
  gap: var(--spacing-md);
}

.breakdown-item {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: var(--spacing-md);
  background: var(--bg-secondary);
  border-radius: var(--radius-md);
  border: 1px solid var(--border-color);
  transition: all var(--transition-fast);
}

.breakdown-item:hover {
  background: var(--bg-tertiary);
}

.breakdown-label {
  color: var(--text-secondary);
  font-weight: 500;
}

.breakdown-value {
  font-weight: 700;
  color: var(--text-primary);
}

/* ===============================================
   GRÁFICO
   =============================================== */

.chart-section {
  padding: 0 var(--spacing-xl) var(--spacing-xl);
}

.chart-title {
  font-size: 1.2rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: var(--spacing-lg);
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
}

.chart-title i {
  color: var(--primary-color);
}

.chart-container {
  background: var(--bg-secondary);
  border-radius: var(--radius-lg);
  padding: var(--spacing-lg);
  border: 1px solid var(--border-color);
  position: relative;
  height: 300px;
}

/* ===============================================
   LOADING OVERLAY
   =============================================== */

.loading-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: var(--bg-overlay);
  backdrop-filter: blur(4px);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 1000;
}

.loading-spinner {
  background: var(--bg-card);
  border-radius: var(--radius-xl);
  padding: var(--spacing-2xl);
  box-shadow: var(--shadow-xl);
  text-align: center;
  border: 1px solid var(--border-color);
}

.loading-spinner i {
  font-size: 3rem;
  color: var(--primary-color);
  margin-bottom: var(--spacing-md);
}

.loading-spinner p {
  color: var(--text-secondary);
  font-weight: 600;
}

/* ===============================================
   FOOTER
   =============================================== */

.footer {
  margin-top: var(--spacing-2xl);
  background: var(--bg-card);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-lg);
  border: 1px solid var(--border-color);
}

.footer-content {
  padding: var(--spacing-lg) var(--spacing-xl);
  text-align: center;
}

.footer-content p {
  color: var(--text-secondary);
  margin-bottom: var(--spacing-sm);
}

.footer-content p:last-child {
  margin-bottom: 0;
}

.disclaimer {
  font-size: 0.9rem;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-sm);
}

.disclaimer i {
  color: var(--warning-color);
}

/* ===============================================
   RESPONSIVE DESIGN
   =============================================== */

@media (max-width: 1023px) {
  .main-content {
    grid-template-columns: 1fr;
  }
  
  .calculator-section {
    order: 1;
  }
  
  .results-section {
    order: 2;
  }
}

@media (max-width: 767px) {
  .container {
    padding: var(--spacing-sm);
  }
  
  .header-content {
    padding: var(--spacing-md);
    flex-direction: column;
    gap: var(--spacing-md);
  }
  
  .header-title h1 {
    font-size: 1.5rem;
  }
  
  .form-row {
    grid-template-columns: 1fr;
  }
  
  .results-grid {
    grid-template-columns: 1fr;
    padding: var(--spacing-md);
  }
  
  .breakdown-section,
  .chart-section {
    padding: 0 var(--spacing-md) var(--spacing-md);
  }
  
  .form-actions {
    flex-direction: column;
  }
  
  .btn {
    min-width: auto;
  }
}

@media (max-width: 479px) {
  .container {
    padding: var(--spacing-xs);
  }
  
  .calculator-form {
    padding: var(--spacing-md);
  }
  
  .header-title {
    flex-direction: column;
    gap: var(--spacing-sm);
  }
  
  .header-title h1 {
    font-size: 1.25rem;
  }
  
  .result-item {
    flex-direction: column;
    text-align: center;
    gap: var(--spacing-sm);
  }
  
  .result-icon {
    width: 2.5rem;
    height: 2.5rem;
    font-size: 1rem;
  }
  
  .result-value {
    font-size: 1.25rem;
  }
  
  .breakdown-item {
    flex-direction: column;
    align-items: flex-start;
    gap: var(--spacing-xs);
  }
}

/* ===============================================
   UTILIDADES Y ANIMACIONES
   =============================================== */

.fade-in {
  animation: fadeIn var(--transition-slow) ease-out;
}

@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

.slide-up {
  animation: slideUp var(--transition-normal) ease-out;
}

@keyframes slideUp {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.pulse {
  animation: pulse 2s infinite;
}

@keyframes pulse {
  0%, 100% {
    opacity: 1;
  }
  50% {
    opacity: 0.7;
  }
}

/* Smooth scroll */
html {
  scroll-behavior: smooth;
}

/* Focus visible para accesibilidad */
.btn:focus-visible,
input:focus-visible {
  outline: 2px solid var(--primary-color);
  outline-offset: 2px;
}

/* Print styles */
@media print {
  .header-controls,
  .form-actions,
  .footer {
    display: none;
  }
  
  .calculator-card,
  .results-card {
    box-shadow: none;
    border: 1px solid #000;
  }
}