/* Modern CSS with CSS Variables and Contemporary Design */
:root {
  /* Color Palette */
  --primary-color: #4591ed;
  --primary-dark: #2c77d3;
  --primary-light: #6ba3f0;
  --secondary-color: #2359B2;
  --accent-color: #ff6b35;
  
  /* Text Colors */
  --text-primary: #333333;
  --text-secondary: #666666;
  --text-muted: #999999;
  --text-light: #ffffff;
  
  /* Background Colors */
  --bg-primary: #ffffff;
  --bg-secondary: #f8f9fa;
  --bg-dark: #2c2f34;
  --bg-light: #f5f5f5;
  
  /* Border & Shadow */
  --border-color: #e9ecef;
  --border-radius: 8px;
  --border-radius-lg: 12px;
  --border-radius-sm: 4px;
  --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.1);
  --shadow-md: 0 4px 8px rgba(0, 0, 0, 0.15);
  --shadow-lg: 0 8px 16px rgba(0, 0, 0, 0.2);
  
  /* Typography */
  --font-family-primary: 'Open Sans', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-family-heading: 'Roboto Slab', Georgia, serif;
  --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;
  
  /* Spacing */
  --spacing-xs: 0.25rem;
  --spacing-sm: 0.5rem;
  --spacing-md: 1rem;
  --spacing-lg: 1.5rem;
  --spacing-xl: 2rem;
  --spacing-2xl: 3rem;
  --spacing-3xl: 4rem;
  
  /* Transitions */
  --transition-fast: 0.15s ease;
  --transition-base: 0.3s ease;
  --transition-slow: 0.5s ease;
  
  /* Breakpoints */
  --breakpoint-sm: 576px;
  --breakpoint-md: 768px;
  --breakpoint-lg: 992px;
  --breakpoint-xl: 1200px;
  --breakpoint-xxl: 1400px;
}

/* Modern Reset & Base Styles */
*,
*::before,
*::after {
  box-sizing: border-box;
}

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

body {
  font-family: var(--font-family-primary);
  font-size: var(--font-size-base);
  line-height: 1.6;
  color: var(--text-primary);
  background-color: var(--bg-primary);
  margin: 0;
  padding: 0;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* Modern Typography */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-family-heading);
  font-weight: 600;
  line-height: 1.2;
  margin: 0 0 var(--spacing-md) 0;
  color: var(--text-primary);
}

h1 { font-size: var(--font-size-4xl); }
h2 { font-size: var(--font-size-3xl); }
h3 { font-size: var(--font-size-2xl); }
h4 { font-size: var(--font-size-xl); }
h5 { font-size: var(--font-size-lg); }
h6 { font-size: var(--font-size-base); }

p {
  margin: 0 0 var(--spacing-md) 0;
  color: var(--text-secondary);
}

/* Modern Button System */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: var(--spacing-sm) var(--spacing-lg);
  font-family: var(--font-family-primary);
  font-size: var(--font-size-base);
  font-weight: 600;
  line-height: 1.5;
  text-decoration: none;
  border: 2px solid transparent;
  border-radius: var(--border-radius);
  cursor: pointer;
  transition: all var(--transition-base);
  position: relative;
  overflow: hidden;
}

.btn:focus {
  outline: none;
  box-shadow: 0 0 0 3px rgba(69, 145, 237, 0.3);
}

.btn-primary {
  background-color: var(--primary-color);
  color: var(--text-light);
  border-color: var(--primary-color);
}

.btn-primary:hover {
  background-color: var(--primary-dark);
  border-color: var(--primary-dark);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.btn-secondary {
  background-color: transparent;
  color: var(--primary-color);
  border-color: var(--primary-color);
}

.btn-secondary:hover {
  background-color: var(--primary-color);
  color: var(--text-light);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.btn-outline {
  background-color: transparent;
  color: var(--text-primary);
  border-color: var(--border-color);
}

.btn-outline:hover {
  background-color: var(--bg-secondary);
  border-color: var(--text-secondary);
}

/* Modern Card System */
.card {
  background: var(--bg-primary);
  border-radius: var(--border-radius-lg);
  box-shadow: var(--shadow-sm);
  padding: var(--spacing-lg);
  transition: all var(--transition-base);
  border: 1px solid var(--border-color);
}

.card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-4px);
}

.card-header {
  padding-bottom: var(--spacing-md);
  border-bottom: 1px solid var(--border-color);
  margin-bottom: var(--spacing-lg);
}

.card-title {
  font-size: var(--font-size-xl);
  font-weight: 600;
  margin: 0;
  color: var(--text-primary);
}

.card-body {
  color: var(--text-secondary);
}

/* Modern Grid System */
.grid {
  display: grid;
  gap: var(--spacing-lg);
}

.grid-2 {
  grid-template-columns: repeat(2, 1fr);
}

.grid-3 {
  grid-template-columns: repeat(3, 1fr);
}

.grid-4 {
  grid-template-columns: repeat(4, 1fr);
}

.grid-auto-fit {
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
}

/* Modern Flexbox Utilities */
.flex {
  display: flex;
}

.flex-center {
  display: flex;
  align-items: center;
  justify-content: center;
}

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

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

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

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

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

/* Modern Navigation */
.nav {
  display: flex;
  align-items: center;
  gap: var(--spacing-lg);
}

.nav-link {
  color: var(--text-secondary);
  text-decoration: none;
  font-weight: 500;
  transition: color var(--transition-base);
  position: relative;
}

.nav-link:hover {
  color: var(--primary-color);
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 2px;
  background-color: var(--primary-color);
  transition: width var(--transition-base);
}

.nav-link:hover::after {
  width: 100%;
}

/* Modern Form Elements */
.form-group {
  margin-bottom: var(--spacing-lg);
}

.form-label {
  display: block;
  margin-bottom: var(--spacing-sm);
  font-weight: 600;
  color: var(--text-primary);
}

.form-control {
  width: 100%;
  padding: var(--spacing-sm) var(--spacing-md);
  font-family: var(--font-family-primary);
  font-size: var(--font-size-base);
  line-height: 1.5;
  color: var(--text-primary);
  background-color: var(--bg-primary);
  border: 1px solid var(--border-color);
  border-radius: var(--border-radius);
  transition: all var(--transition-base);
}

.form-control:focus {
  outline: none;
  border-color: var(--primary-color);
  box-shadow: 0 0 0 3px rgba(69, 145, 237, 0.1);
}

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

/* Modern Utilities */
.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }

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

.bg-primary { background-color: var(--primary-color); }
.bg-secondary { background-color: var(--bg-secondary); }
.bg-dark { background-color: var(--bg-dark); }
.bg-light { background-color: var(--bg-light); }

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

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

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

/* Responsive Design */
@media (max-width: 768px) {
  .grid-2,
  .grid-3,
  .grid-4 {
    grid-template-columns: 1fr;
  }
  
  .container {
    padding: 0 var(--spacing-md);
  }
  
  h1 { font-size: var(--font-size-3xl); }
  h2 { font-size: var(--font-size-2xl); }
  h3 { font-size: var(--font-size-xl); }
  
  .btn {
    padding: var(--spacing-md) var(--spacing-lg);
    font-size: var(--font-size-base);
  }
}

@media (max-width: 576px) {
  .container {
    padding: 0 var(--spacing-sm);
  }
  
  .card {
    padding: var(--spacing-md);
  }
  
  .btn {
    width: 100%;
    justify-content: center;
  }
}

/* Modern Animations */
@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  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);
  }
}

.animate-fade-in {
  animation: fadeIn 0.6s ease-out;
}

.animate-slide-left {
  animation: slideInLeft 0.6s ease-out;
}

.animate-slide-right {
  animation: slideInRight 0.6s ease-out;
}

/* Modern Loading States */
.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, 0.4), transparent);
  animation: loading 1.5s infinite;
}

@keyframes loading {
  0% { left: -100%; }
  100% { left: 100%; }
}

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

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

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

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

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