/* Modern CSS Variables */
:root {
  --primary-color: #2c3e50;
  --secondary-color: #3498db;
  --success-color: #27ae60;
  --warning-color: #f39c12;
  --danger-color: #e74c3c;
  --light-bg: #f8f9fa;
  --dark-text: #2c3e50;
  --border-radius: 8px;
  --box-shadow: 0 2px 10px rgba(0,0,0,0.1);
  --transition: all 0.3s ease;
}

/* Base Styles */
html {
  font-size: 14px;
  position: relative;
  min-height: 100%;
}

@media (min-width: 768px) {
  html {
    font-size: 16px;
  }
}

body {
  margin-bottom: 60px;
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  background-color: var(--light-bg);
  color: var(--dark-text);
  line-height: 1.6;
}

/* Focus States */
.btn:focus, .btn:active:focus, .btn-link.nav-link:focus, .form-control:focus, .form-check-input:focus {
  box-shadow: 0 0 0 0.2rem rgba(52, 152, 219, 0.25);
  border-color: var(--secondary-color);
}

/* Custom Components */
.card {
  border: none;
  border-radius: var(--border-radius);
  box-shadow: var(--box-shadow);
  transition: var(--transition);
}

.card:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 20px rgba(0,0,0,0.15);
}

.btn {
  border-radius: var(--border-radius);
  font-weight: 500;
  transition: var(--transition);
  border: none;
  padding: 0.5rem 1rem;
}

.btn:hover {
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(0,0,0,0.15);
}

.btn-primary {
  background: linear-gradient(135deg, var(--secondary-color), #2980b9);
}

.btn-success {
  background: linear-gradient(135deg, var(--success-color), #229954);
}

.btn-danger {
  background: linear-gradient(135deg, var(--danger-color), #c0392b);
}

.btn-warning {
  background: linear-gradient(135deg, var(--warning-color), #e67e22);
}

/* Navigation */
.navbar {
  background: linear-gradient(135deg, #fff, #f8f9fa) !important;
  box-shadow: 0 2px 20px rgba(0,0,0,0.1);
  border: none !important;
}

.navbar-brand {
  font-weight: 700;
  font-size: 1.5rem;
  color: var(--primary-color) !important;
}

.nav-link {
  color: var(--dark-text) !important;
  font-weight: 500;
  transition: var(--transition);
}

.nav-link:hover {
  color: var(--secondary-color) !important;
  transform: translateY(-1px);
}

/* Tables */
.table {
  background: white;
  border-radius: var(--border-radius);
  overflow: hidden;
  box-shadow: var(--box-shadow);
}

.table thead th {
  background: linear-gradient(135deg, var(--primary-color), #34495e);
  color: white;
  border: none;
  font-weight: 600;
  text-transform: uppercase;
  font-size: 0.85rem;
  letter-spacing: 0.5px;
}

.table tbody tr {
  transition: var(--transition);
}

.table tbody tr:hover {
  background-color: rgba(52, 152, 219, 0.05);
  transform: scale(1.01);
}

/* Forms */
.form-control {
  border-radius: var(--border-radius);
  border: 2px solid #e9ecef;
  transition: var(--transition);
  padding: 0.75rem 1rem;
}

.form-control:focus {
  border-color: var(--secondary-color);
  box-shadow: 0 0 0 0.2rem rgba(52, 152, 219, 0.25);
}

.form-label {
  font-weight: 600;
  color: var(--dark-text);
  margin-bottom: 0.5rem;
}

/* Status Indicators */
span.outdated {
  color: var(--danger-color);
  font-weight: 600;
  background: rgba(231, 76, 60, 0.1);
  padding: 0.25rem 0.5rem;
  border-radius: 4px;
}

.badge {
  border-radius: 20px;
  padding: 0.5rem 0.75rem;
  font-weight: 500;
}

/* Custom Utilities */
.gradient-bg {
  background: linear-gradient(135deg, var(--secondary-color), #2980b9);
}

.text-gradient {
  background: linear-gradient(135deg, var(--secondary-color), #2980b9);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.shadow-custom {
  box-shadow: var(--box-shadow);
}

.border-radius-custom {
  border-radius: var(--border-radius);
}

/* Animations */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.fade-in-up {
  animation: fadeInUp 0.6s ease-out;
}

/* Responsive Design */
@media (max-width: 768px) {
  .btn-group {
    flex-direction: column;
  }
  
  .btn-group .btn {
    margin-bottom: 0.25rem;
    border-radius: var(--border-radius) !important;
  }
  
  .table-responsive {
    border-radius: var(--border-radius);
  }
}

/* Footer */
.footer {
  background: linear-gradient(135deg, var(--primary-color), #34495e);
  color: white;
  margin-top: auto;
}

/* Document Viewer Specific */
.document-viewer {
  background: white;
  border-radius: var(--border-radius);
  box-shadow: var(--box-shadow);
  padding: 2rem;
  margin: 1rem 0;
}

.document-actions {
  position: sticky;
  top: 1rem;
  z-index: 1000;
}

/* Loading States */
.loading {
  opacity: 0.6;
  pointer-events: none;
}

.spinner {
  display: inline-block;
  width: 20px;
  height: 20px;
  border: 3px solid rgba(255,255,255,.3);
  border-radius: 50%;
  border-top-color: #fff;
  animation: spin 1s ease-in-out infinite;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}