/* ===================================
   BASE STYLES - StudyQuality System
   Basado en principios de Calidad de Software
   ================================== */

/* CSS Reset y Variables */
:root {
  /* Colores Principales */
  --primary-color: #3498db;
  --primary-dark: #2980b9;
  --primary-light: #5dade2;
  
  --secondary-color: #2c3e50;
  --secondary-dark: #1a252f;
  --secondary-light: #34495e;
  
  --success-color: #27ae60;
  --success-dark: #229954;
  --success-light: #58d68d;
  
  --warning-color: #f39c12;
  --warning-dark: #e67e22;
  --warning-light: #f8c471;
  
  --danger-color: #e74c3c;
  --danger-dark: #c0392b;
  --danger-light: #ec7063;
  
  --info-color: #17a2b8;
  --info-dark: #138496;
  --info-light: #5dccdb;
  
  /* Colores de Interfaz */
  --background-color: #f8f9fa;
  --surface-color: #ffffff;
  --overlay-color: rgba(0, 0, 0, 0.5);
  
  --text-primary: #2c3e50;
  --text-secondary: #7f8c8d;
  --text-muted: #95a5a6;
  --text-inverse: #ffffff;
  
  --border-color: #dee2e6;
  --border-light: #e9ecef;
  --border-dark: #adb5bd;
  
  /* Gradientes */
  --gradient-primary: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  --gradient-success: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
  --gradient-warning: linear-gradient(135deg, #fa709a 0%, #fee140 100%);
  --gradient-danger: linear-gradient(135deg, #ff8a80 0%, #ff5722 100%);
  
  /* Tipografía */
  --font-family-primary: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  --font-family-monospace: 'Monaco', 'Menlo', 'Ubuntu Mono', monospace;
  
  --font-size-xs: 0.75rem;
  --font-size-sm: 0.875rem;
  --font-size-base: 1rem;
  --font-size-lg: 1.125rem;
  --font-size-xl: 1.25rem;
  --font-size-2xl: 1.5rem;
  --font-size-3xl: 1.875rem;
  --font-size-4xl: 2.25rem;
  
  --font-weight-light: 300;
  --font-weight-normal: 400;
  --font-weight-medium: 500;
  --font-weight-semibold: 600;
  --font-weight-bold: 700;
  
  --line-height-tight: 1.25;
  --line-height-normal: 1.5;
  --line-height-relaxed: 1.75;
  
  /* Espaciado */
  --spacing-xs: 0.25rem;
  --spacing-sm: 0.5rem;
  --spacing-md: 1rem;
  --spacing-lg: 1.5rem;
  --spacing-xl: 2rem;
  --spacing-2xl: 3rem;
  --spacing-3xl: 4rem;
  
  /* Bordes y Sombras */
  --border-radius-sm: 0.25rem;
  --border-radius-md: 0.5rem;
  --border-radius-lg: 0.75rem;
  --border-radius-xl: 1rem;
  --border-radius-full: 50%;
  
  --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);
  --shadow-2xl: 0 25px 50px -12px rgba(0, 0, 0, 0.25);
  
  /* Transiciones */
  --transition-fast: 0.15s ease-in-out;
  --transition-normal: 0.3s ease-in-out;
  --transition-slow: 0.5s ease-in-out;
  
  /* Z-index */
  --z-dropdown: 1000;
  --z-sticky: 1020;
  --z-fixed: 1030;
  --z-modal-backdrop: 1040;
  --z-modal: 1050;
  --z-popover: 1060;
  --z-tooltip: 1070;
}

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

*::before,
*::after {
  box-sizing: border-box;
}

html {
  font-size: 16px;
  line-height: 1.15;
  -webkit-text-size-adjust: 100%;
  -webkit-tap-highlight-color: transparent;
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-family-primary);
  font-size: var(--font-size-base);
  font-weight: var(--font-weight-normal);
  line-height: var(--line-height-normal);
  color: var(--text-primary);
  background: var(--gradient-primary);
  min-height: 100vh;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* Elementos de Base */
h1, h2, h3, h4, h5, h6 {
  margin-bottom: var(--spacing-sm);
  font-weight: var(--font-weight-semibold);
  line-height: var(--line-height-tight);
  color: var(--text-primary);
}

h1 { font-size: var(--font-size-3xl); }
h2 { font-size: var(--font-size-2xl); }
h3 { font-size: var(--font-size-xl); }
h4 { font-size: var(--font-size-lg); }
h5 { font-size: var(--font-size-base); }
h6 { font-size: var(--font-size-sm); }

p {
  margin-bottom: var(--spacing-md);
  color: var(--text-secondary);
}

a {
  color: var(--primary-color);
  text-decoration: none;
  transition: color var(--transition-fast);
}

a:hover {
  color: var(--primary-dark);
  text-decoration: underline;
}

img {
  max-width: 100%;
  height: auto;
  display: block;
}

/* Layout Principal */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: var(--spacing-lg);
  position: relative;
}

/* Utilidades de Flexbox */
.flex {
  display: flex;
}

.flex-col {
  flex-direction: column;
}

.flex-wrap {
  flex-wrap: wrap;
}

.items-center {
  align-items: center;
}

.items-start {
  align-items: flex-start;
}

.items-end {
  align-items: flex-end;
}

.justify-center {
  justify-content: center;
}

.justify-between {
  justify-content: space-between;
}

.justify-around {
  justify-content: space-around;
}

.justify-start {
  justify-content: flex-start;
}

.justify-end {
  justify-content: flex-end;
}

/* Utilidades de Grid */
.grid {
  display: grid;
}

.grid-cols-1 { grid-template-columns: repeat(1, minmax(0, 1fr)); }
.grid-cols-2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid-cols-3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid-cols-4 { grid-template-columns: repeat(4, minmax(0, 1fr)); }

.gap-sm { gap: var(--spacing-sm); }
.gap-md { gap: var(--spacing-md); }
.gap-lg { gap: var(--spacing-lg); }
.gap-xl { gap: var(--spacing-xl); }

/* Utilidades de Espaciado */
.m-0 { margin: 0; }
.m-sm { margin: var(--spacing-sm); }
.m-md { margin: var(--spacing-md); }
.m-lg { margin: var(--spacing-lg); }
.m-xl { margin: var(--spacing-xl); }

.mt-0 { margin-top: 0; }
.mt-sm { margin-top: var(--spacing-sm); }
.mt-md { margin-top: var(--spacing-md); }
.mt-lg { margin-top: var(--spacing-lg); }
.mt-xl { margin-top: var(--spacing-xl); }

.mb-0 { margin-bottom: 0; }
.mb-sm { margin-bottom: var(--spacing-sm); }
.mb-md { margin-bottom: var(--spacing-md); }
.mb-lg { margin-bottom: var(--spacing-lg); }
.mb-xl { margin-bottom: var(--spacing-xl); }

.p-0 { padding: 0; }
.p-sm { padding: var(--spacing-sm); }
.p-md { padding: var(--spacing-md); }
.p-lg { padding: var(--spacing-lg); }
.p-xl { padding: var(--spacing-xl); }

/* Utilidades de Texto */
.text-left { text-align: left; }
.text-center { text-align: center; }
.text-right { text-align: right; }
.text-justify { text-align: justify; }

.text-xs { font-size: var(--font-size-xs); }
.text-sm { font-size: var(--font-size-sm); }
.text-base { font-size: var(--font-size-base); }
.text-lg { font-size: var(--font-size-lg); }
.text-xl { font-size: var(--font-size-xl); }

.font-light { font-weight: var(--font-weight-light); }
.font-normal { font-weight: var(--font-weight-normal); }
.font-medium { font-weight: var(--font-weight-medium); }
.font-semibold { font-weight: var(--font-weight-semibold); }
.font-bold { font-weight: var(--font-weight-bold); }

.text-primary { color: var(--text-primary); }
.text-secondary { color: var(--text-secondary); }
.text-muted { color: var(--text-muted); }
.text-inverse { color: var(--text-inverse); }

/* Utilidades de Visibilidad */
.hidden {
  display: none !important;
}

.visible {
  display: block !important;
}

.invisible {
  visibility: hidden;
}

.opacity-0 { opacity: 0; }
.opacity-50 { opacity: 0.5; }
.opacity-75 { opacity: 0.75; }
.opacity-100 { opacity: 1; }

/* Utilidades de Posicionamiento */
.relative { position: relative; }
.absolute { position: absolute; }
.fixed { position: fixed; }
.sticky { position: sticky; }

.top-0 { top: 0; }
.right-0 { right: 0; }
.bottom-0 { bottom: 0; }
.left-0 { left: 0; }

/* Componentes de Carga */
.loading-screen {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: var(--gradient-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 9999;
  transition: opacity var(--transition-slow), visibility var(--transition-slow);
}

.loading-screen.hidden {
  opacity: 0;
  visibility: hidden;
}

.loading-content {
  text-align: center;
  color: var(--text-inverse);
}

.loading-content h2 {
  color: var(--text-inverse);
  font-size: var(--font-size-3xl);
  margin: var(--spacing-lg) 0 var(--spacing-sm);
  font-weight: var(--font-weight-bold);
}

.loading-content p {
  color: rgba(255, 255, 255, 0.8);
  font-size: var(--font-size-lg);
}

/* Spinner de Carga */
.spinner {
  width: 50px;
  height: 50px;
  border: 4px solid rgba(255, 255, 255, 0.3);
  border-top: 4px solid var(--text-inverse);
  border-radius: var(--border-radius-full);
  animation: spin 1s linear infinite;
  margin: 0 auto;
}

@keyframes spin {
  0% { transform: rotate(0deg); }
  100% { transform: rotate(360deg); }
}

/* Loading Overlay */
.loading-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: var(--overlay-color);
  display: none;
  align-items: center;
  justify-content: center;
  z-index: var(--z-modal);
  backdrop-filter: blur(5px);
}

.loading-overlay.active {
  display: flex;
}

.loading-overlay .loading-content {
  background: var(--surface-color);
  padding: var(--spacing-xl);
  border-radius: var(--border-radius-lg);
  box-shadow: var(--shadow-xl);
  text-align: center;
  min-width: 200px;
}

.loading-overlay .spinner {
  border-color: var(--border-light);
  border-top-color: var(--primary-color);
  margin-bottom: var(--spacing-md);
}

.loading-overlay p {
  color: var(--text-primary);
  margin: 0;
  font-weight: var(--font-weight-medium);
}

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

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

::-webkit-scrollbar-thumb {
  background: var(--border-dark);
  border-radius: var(--border-radius-sm);
}

::-webkit-scrollbar-thumb:hover {
  background: var(--text-secondary);
}

/* Selección de texto */
::selection {
  background: var(--primary-light);
  color: var(--text-inverse);
}

::-moz-selection {
  background: var(--primary-light);
  color: var(--text-inverse);
}

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

/* Utilidades de accesibilidad */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

/* Estados de hover para elementos interactivos */
.hover-lift {
  transition: transform var(--transition-fast), box-shadow var(--transition-fast);
}

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

/* Animaciones de entrada */
@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

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

@keyframes slideInFromLeft {
  from {
    opacity: 0;
    transform: translateX(-30px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

.animate-fade-in {
  animation: fadeIn 0.5s ease-out;
}

.animate-slide-in-right {
  animation: slideInFromRight 0.3s ease-out;
}

.animate-slide-in-left {
  animation: slideInFromLeft 0.3s ease-out;
}

/* Media queries base */
@media (max-width: 768px) {
  .container {
    padding: var(--spacing-md);
  }
  
  h1 { font-size: var(--font-size-2xl); }
  h2 { font-size: var(--font-size-xl); }
  h3 { font-size: var(--font-size-lg); }
}

@media (max-width: 480px) {
  .container {
    padding: var(--spacing-sm);
  }
  
  h1 { font-size: var(--font-size-xl); }
  h2 { font-size: var(--font-size-lg); }
}

/* Utilidades de desarrollo (solo para debug) */
.debug-border {
  border: 1px solid red !important;
}

.debug-bg {
  background: rgba(255, 0, 0, 0.1) !important;
}

/* Print styles */
@media print {
  .no-print {
    display: none !important;
  }
  
  body {
    background: white !important;
    color: black !important;
  }
  
  .container {
    max-width: none !important;
    padding: 0 !important;
  }
}