:root {
    /* Base colors */
    --background-color-rgb: 255, 255, 255;
    --background-color: #ffffff;
    --text-color: #1a202c;
    
    /* Primary Accent: Fixed Teal */
    --primary-color: #00d1b2;
    --primary-hover: #00b89c;
    --text-on-primary: #ffffff;
    
    /* Secondary & Structural */
    --secondary-color: #718096;
    --border-color: #e2e8f0;
    
    /* Header (Nav maintains a dark premium look in both modes) */
    --header-bg: #1a202c;
    --header-bg-rgb: 26, 32, 44;
    --header-text: #ffffff;
}

[data-bs-theme="dark"] {
    /* Base colors */
    --background-color-rgb: 18, 18, 18;
    --background-color: #121212;
    --text-color: #f7fafc;
    
    /* Header overrides */
    --header-bg: #1a202c !important;
    --header-text: #ffffff !important;

    /* Primary Accent: Fixed Teal */
    --primary-color: #00d1b2;
    --primary-hover: #00e6c3; /* Lighter hover in dark mode */
    --text-on-primary: #121212; /* Better contrast in dark mode */
    
    /* Secondary & Structural */
    --secondary-color: #a0aec0;
    --border-color: #2d3748;
    
    /* Inverse Grays for Custom Components using var(--gray-*) */
    --gray-50: #1e2430;
    --gray-100: #2d3748;
    --gray-200: #4a5568;
    --gray-300: #718096;
    
    /* Header (Nav maintains a dark premium look in both modes) */
    --header-bg: #1a202c;
    --header-bg-rgb: 26, 32, 44;
    --header-text: #ffffff;
    
    /* Links */
    --link-color: #00e6c3;
    --link-hover-color: #00d1b2;
}

[data-bs-theme="dark"] .text-muted {
    color: #a0aec0 !important;
}

body {
    background-color: var(--background-color);
    color: var(--text-color);
    transition: background-color 0.3s ease, color 0.3s ease;
}

/* Navbar Overrides */
.navbar-modern {
    background-color: var(--header-bg) !important;
}

[data-bs-theme="dark"] .navbar-modern {
    border-bottom: 1px solid var(--border-color);
}

.navbar-modern .nav-link,
.navbar-modern .navbar-brand {
    color: var(--header-text) !important;
}

.utility-bar {
    background-color: var(--background-color);
    border-bottom: 1px solid var(--border-color);
    color: var(--text-color);
}

.utility-bar .dropdown-menu {
    position: relative;
    z-index: 1040;
}

/* Sober Glassmorphism */
.glass-panel {
  background: rgba(255, 255, 255, 0.7);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid rgba(255, 255, 255, 0.4);
  box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
  border-radius: var(--border-radius-lg, 15px);
}

[data-bs-theme="dark"] .glass-panel {
  background: rgba(30, 30, 30, 0.7);
  border-color: rgba(255, 255, 255, 0.1);
  box-shadow: 0 4px 6px rgba(0, 0, 0, 0.2);
}

/* Buttons overriding Bootstrap */
.btn-primary {
  background-color: var(--primary-color) !important;
  border-color: var(--primary-color) !important;
  color: var(--text-on-primary) !important;
}

.btn-primary:hover, .btn-primary:focus {
  background-color: var(--primary-hover) !important;
  border-color: var(--primary-hover) !important;
  color: var(--text-on-primary) !important;
  box-shadow: 0 0 0 3px rgba(0, 209, 178, 0.2);
}

.btn-outline-secondary {
  color: var(--text-color) !important;
  border-color: var(--border-color);
}

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

.btn-outline-primary {
  color: var(--primary-color) !important;
  border-color: var(--primary-color) !important;
}

.btn-outline-primary:hover {
  background-color: var(--primary-color) !important;
  color: var(--text-on-primary) !important;
}

.btn-info {
  background-color: #3e8ed0;
  border-color: #3e8ed0;
  color: #fff !important;
}

a {
  color: var(--link-color);
  text-decoration: none;
  transition: color 0.2s ease;
}

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

.badge.bg-secondary { 
    color: #fff !important; 
    background-color: #718096 !important; 
}

[data-theme="dark"] .badge.bg-secondary {
  color: #121212 !important;
  background-color: #a0aec0 !important;
}

/* Compact breadcrumb bar */
.breadcrumb-bar {
    background-color: var(--header-bg);
    color: var(--header-text);
    border-color: rgba(255, 255, 255, 0.05) !important;
}

.breadcrumb-bar .breadcrumb {
    margin-bottom: 0;
    font-size: 0.875rem;
}

.breadcrumb-bar .breadcrumb-item,
.breadcrumb-bar .breadcrumb-item.active,
.breadcrumb-bar .breadcrumb-item a {
    color: rgba(255, 255, 255, 0.7);
}

.breadcrumb-bar .breadcrumb-item a:hover {
    color: #ffffff;
    text-decoration: underline;
}

/* Compensations Visuelles en Mode Sombre (Cartes sans ombre noire) */
[data-bs-theme="dark"] .card, 
[data-bs-theme="dark"] .card-modern,
[data-bs-theme="dark"] .book-card,
[data-bs-theme="dark"] .entity-card {
    border: 1px solid var(--border-color) !important;
    background-color: var(--gray-100) !important;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.5) !important;
}

[data-bs-theme="dark"] .bg-light {
    background-color: var(--gray-100) !important;
    color: var(--text-color) !important;
    border-color: var(--border-color) !important;
}

/* ====== Further Dark Mode Enhancements for Specific Sections ====== */
[data-bs-theme="dark"] .page-header {
    background-color: var(--header-bg) !important;
    border-bottom: 1px solid var(--border-color) !important;
    color: var(--text-color) !important;
}

[data-bs-theme="dark"] .page-header h1 {
    color: var(--text-color) !important;
}

[data-bs-theme="dark"] .home-search-section {
    background-color: var(--gray-100) !important;
    border-bottom: 1px solid var(--border-color) !important;
}

[data-bs-theme="dark"] .utility-bar,
[data-bs-theme="dark"] .utility-bar.bg-light {
    background-color: var(--header-bg) !important;
    border-bottom: 1px solid var(--border-color) !important;
    color: var(--text-color) !important;
}

[data-bs-theme="dark"] .nav-link {
    color: var(--text-color) !important;
}

[data-bs-theme="dark"] .nav-link:hover {
    color: var(--link-hover-color) !important;
}

[data-bs-theme="dark"] .card.h-100.animate-in {
    border: 1px solid var(--border-color) !important;
    background-color: var(--gray-100) !important;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.5) !important;
}

[data-bs-theme="dark"] .d-flex.justify-content-between.align-items-center.mt-3.mb-3 {
    background-color: transparent !important;
}

/* Ensure padding 4rem 0 and background gray-50 translates well in dark mode */
[data-bs-theme="dark"] [style*="padding: 4rem 0; background: var(--gray-50);"],
[data-bs-theme="dark"] [style*="padding: 3rem 0; background: var(--gray-50);"] {
    background: var(--gray-100) !important;
}

/* Compensating for lost shadow on all cards in dark mode by adding a subtle border */
[data-bs-theme="dark"] .card,
[data-bs-theme="dark"] .card-modern,
[data-bs-theme="dark"] .book-card,
[data-bs-theme="dark"] .entity-card {
    border: 1px solid var(--border-color) !important;
    background-color: var(--gray-100) !important;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.3) !important;
}

/* Background utilities and common components missing from bootstrap 5 built-in dark mode if hardcoded */
[data-bs-theme="dark"] .bg-light,
[data-bs-theme="dark"] .bg-white,
[data-bs-theme="dark"] .bg-transparent,
[data-bs-theme="dark"] .list-item,
[data-bs-theme="dark"] .empty-state,
[data-bs-theme="dark"] .filters {
    background-color: var(--gray-100) !important;
    color: var(--text-color) !important;
    border-color: var(--border-color) !important;
}

[data-bs-theme="dark"] .table {
    --bs-table-bg: var(--gray-100);
    --bs-table-color: var(--text-color);
    --bs-table-border-color: var(--border-color);
    --bs-table-striped-bg: rgba(255, 255, 255, 0.05);
    --bs-table-hover-bg: rgba(255, 255, 255, 0.1);
    color: var(--text-color);
}

[data-bs-theme="dark"] .form-control,
[data-bs-theme="dark"] .form-select {
    background-color: var(--gray-50);
    border-color: var(--border-color);
    color: var(--text-color);
}

[data-bs-theme="dark"] .form-control::placeholder {
    color: var(--gray-300);
}

[data-bs-theme="dark"] .form-control:focus,
[data-bs-theme="dark"] .form-select:focus {
    background-color: var(--gray-100);
    color: var(--text-color);
    border-color: var(--primary-color);
    box-shadow: 0 0 0 0.25rem rgba(0, 209, 178, 0.25);
}

/* Fix Labels contrast on some forms */
[data-bs-theme="dark"] .form-label, 
[data-bs-theme="dark"] label {
    color: var(--text-color);
}

/* Overlay for background images to ensure contrast */
.bg-overlay-dark {
    position: relative;
    overflow: hidden;
}

.bg-overlay-dark::after {
    content: '';
    position: absolute;
    inset: 0;
    background: rgba(0,0,0,0.5);
    pointer-events: none;
    border-radius: inherit;
}

.bg-overlay-dark > * {
    position: relative;
    z-index: 1;
    color: #ffffff;
}

/* Increase internal padding for modern cards */
.card-modern .card-body {
    padding: 1.5rem;
}