/* =========================
   Base Styles & CSS Variables
   ========================= */

:root {
  /* Color Variables */
  --primary-color: #007bff;
  --accent-color: #0056b3;
  --success-color: #28a745;
  --warning-color: #ffc107;
  --danger-color: #dc3545;
  --info-color: #17a2b8;
  
  /* Text Colors */
  --text-color: #2c3e50;
  --text-muted: #6c757d;
  --text-light: #ffffff;
  
  /* Background Colors */
  --bg-primary: #ffffff;
  --bg-secondary: #f8f9fa;
  --bg-dark: #2c3e50;
  
  /* Border Colors */
  --border-color: #dee2e6;
  --border-light: #e9ecef;
  
  /* Shadow Variables */
  --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.1);
  --shadow-md: 0 4px 8px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 10px 30px rgba(0, 0, 0, 0.1);
  --shadow-xl: 0 20px 40px rgba(0, 0, 0, 0.15);
  
  /* Border Radius */
  --border-radius-sm: 4px;
  --border-radius-md: 8px;
  --border-radius-lg: 12px;
  --border-radius-xl: 16px;
  --border-radius-xxl: 20px;
  
  /* Spacing */
  --spacing-xs: 0.25rem;
  --spacing-sm: 0.5rem;
  --spacing-md: 1rem;
  --spacing-lg: 1.5rem;
  --spacing-xl: 2rem;
  --spacing-xxl: 3rem;
  
  /* Typography */
  --font-family-base: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-family-heading: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-size-base: 1rem;
  --font-size-sm: 0.875rem;
  --font-size-lg: 1.125rem;
  --font-size-xl: 1.25rem;
  --line-height-base: 1.6;
  
  /* Transitions */
  --transition-fast: 0.15s ease;
  --transition-base: 0.3s ease;
  --transition-slow: 0.5s ease;
  
  /* 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 & Base Styles */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

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

body {
  font-family: var(--font-family-base);
  font-size: var(--font-size-base);
  line-height: var(--line-height-base);
  color: var(--text-color);
  background-color: var(--bg-primary);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-family-heading);
  font-weight: 700;
  line-height: 1.2;
  margin-bottom: var(--spacing-md);
  color: var(--text-color);
}

h1 { font-size: 2.5rem; }
h2 { font-size: 2rem; }
h3 { font-size: 1.75rem; }
h4 { font-size: 1.5rem; }
h5 { font-size: 1.25rem; }
h6 { font-size: 1rem; }

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

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

a:hover {
  color: var(--accent-color);
}

/* Container */
.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--spacing-md);
}

.container-fluid {
  width: 100%;
  padding: 0 var(--spacing-md);
}

/* Section Spacing */
section {
  padding: var(--spacing-xxl) 0;
}

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

.section-lg {
  padding: calc(var(--spacing-xxl) * 2) 0;
}

/* Utility Classes */
.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }

.text-primary { color: var(--primary-color) !important; }
.text-accent { color: var(--accent-color) !important; }
.text-success { color: var(--success-color) !important; }
.text-warning { color: var(--warning-color) !important; }
.text-danger { color: var(--danger-color) !important; }
.text-info { color: var(--info-color) !important; }
.text-muted { color: var(--text-muted) !important; }
.text-light { color: var(--text-light) !important; }

.bg-primary { background-color: var(--primary-color) !important; }
.bg-accent { background-color: var(--accent-color) !important; }
.bg-success { background-color: var(--success-color) !important; }
.bg-warning { background-color: var(--warning-color) !important; }
.bg-danger { background-color: var(--danger-color) !important; }
.bg-info { background-color: var(--info-color) !important; }
.bg-light { background-color: var(--bg-secondary) !important; }
.bg-dark { background-color: var(--bg-dark) !important; }

/* Spacing Utilities */
.m-0 { margin: 0 !important; }
.m-1 { margin: var(--spacing-xs) !important; }
.m-2 { margin: var(--spacing-sm) !important; }
.m-3 { margin: var(--spacing-md) !important; }
.m-4 { margin: var(--spacing-lg) !important; }
.m-5 { margin: var(--spacing-xl) !important; }

.mt-0 { margin-top: 0 !important; }
.mt-1 { margin-top: var(--spacing-xs) !important; }
.mt-2 { margin-top: var(--spacing-sm) !important; }
.mt-3 { margin-top: var(--spacing-md) !important; }
.mt-4 { margin-top: var(--spacing-lg) !important; }
.mt-5 { margin-top: var(--spacing-xl) !important; }

.mb-0 { margin-bottom: 0 !important; }
.mb-1 { margin-bottom: var(--spacing-xs) !important; }
.mb-2 { margin-bottom: var(--spacing-sm) !important; }
.mb-3 { margin-bottom: var(--spacing-md) !important; }
.mb-4 { margin-bottom: var(--spacing-lg) !important; }
.mb-5 { margin-bottom: var(--spacing-xl) !important; }

.p-0 { padding: 0 !important; }
.p-1 { padding: var(--spacing-xs) !important; }
.p-2 { padding: var(--spacing-sm) !important; }
.p-3 { padding: var(--spacing-md) !important; }
.p-4 { padding: var(--spacing-lg) !important; }
.p-5 { padding: var(--spacing-xl) !important; }

.pt-0 { padding-top: 0 !important; }
.pt-1 { padding-top: var(--spacing-xs) !important; }
.pt-2 { padding-top: var(--spacing-sm) !important; }
.pt-3 { padding-top: var(--spacing-md) !important; }
.pt-4 { padding-top: var(--spacing-lg) !important; }
.pt-5 { padding-top: var(--spacing-xl) !important; }

.pb-0 { padding-bottom: 0 !important; }
.pb-1 { padding-bottom: var(--spacing-xs) !important; }
.pb-2 { padding-bottom: var(--spacing-sm) !important; }
.pb-3 { padding-bottom: var(--spacing-md) !important; }
.pb-4 { padding-bottom: var(--spacing-lg) !important; }
.pb-5 { padding-bottom: var(--spacing-xl) !important; }

/* Display Utilities */
.d-none { display: none !important; }
.d-block { display: block !important; }
.d-inline { display: inline !important; }
.d-inline-block { display: inline-block !important; }
.d-flex { display: flex !important; }
.d-inline-flex { display: inline-flex !important; }
.d-grid { display: grid !important; }

/* Flex Utilities */
.flex-row { flex-direction: row !important; }
.flex-column { flex-direction: column !important; }
.flex-wrap { flex-wrap: wrap !important; }
.flex-nowrap { flex-wrap: nowrap !important; }
.justify-content-start { justify-content: flex-start !important; }
.justify-content-end { justify-content: flex-end !important; }
.justify-content-center { justify-content: center !important; }
.justify-content-between { justify-content: space-between !important; }
.justify-content-around { justify-content: space-around !important; }
.align-items-start { align-items: flex-start !important; }
.align-items-end { align-items: flex-end !important; }
.align-items-center { align-items: center !important; }
.align-items-baseline { align-items: baseline !important; }
.align-items-stretch { align-items: stretch !important; }

/* Border Utilities */
.border { border: 1px solid var(--border-color) !important; }
.border-0 { border: 0 !important; }
.border-top { border-top: 1px solid var(--border-color) !important; }
.border-bottom { border-bottom: 1px solid var(--border-color) !important; }
.border-left { border-left: 1px solid var(--border-color) !important; }
.border-right { border-right: 1px solid var(--border-color) !important; }

.rounded { border-radius: var(--border-radius-md) !important; }
.rounded-sm { border-radius: var(--border-radius-sm) !important; }
.rounded-lg { border-radius: var(--border-radius-lg) !important; }
.rounded-xl { border-radius: var(--border-radius-xl) !important; }
.rounded-circle { border-radius: 50% !important; }

/* Shadow Utilities */
.shadow-sm { box-shadow: var(--shadow-sm) !important; }
.shadow { box-shadow: var(--shadow-md) !important; }
.shadow-lg { box-shadow: var(--shadow-lg) !important; }
.shadow-xl { box-shadow: var(--shadow-xl) !important; }
.shadow-none { box-shadow: none !important; }

/* Position Utilities */
.position-static { position: static !important; }
.position-relative { position: relative !important; }
.position-absolute { position: absolute !important; }
.position-fixed { position: fixed !important; }
.position-sticky { position: sticky !important; }

/* Responsive Utilities */
@media (max-width: 575.98px) {
  .d-sm-none { display: none !important; }
  .d-sm-block { display: block !important; }
  .d-sm-flex { display: flex !important; }
}

@media (max-width: 767.98px) {
  .d-md-none { display: none !important; }
  .d-md-block { display: block !important; }
  .d-md-flex { display: flex !important; }
}

@media (max-width: 991.98px) {
  .d-lg-none { display: none !important; }
  .d-lg-block { display: block !important; }
  .d-lg-flex { display: flex !important; }
}

@media (max-width: 1199.98px) {
  .d-xl-none { display: none !important; }
  .d-xl-block { display: block !important; }
  .d-xl-flex { display: flex !important; }
}

/* Animation Utilities */
.fade-in {
  animation: fadeIn var(--transition-base) ease-in;
}

.slide-in-up {
  animation: slideInUp var(--transition-base) ease-out;
}

.slide-in-down {
  animation: slideInDown var(--transition-base) ease-out;
}

.slide-in-left {
  animation: slideInLeft var(--transition-base) ease-out;
}

.slide-in-right {
  animation: slideInRight var(--transition-base) ease-out;
}

/* Keyframe Animations */
@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

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

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

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

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

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

/* Selection Styles */
::selection {
  background-color: var(--primary-color);
  color: white;
}

::-moz-selection {
  background-color: var(--primary-color);
  color: white;
}

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

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

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

::-webkit-scrollbar-thumb:hover {
  background: var(--accent-color);
}