/* Dark/Light Mode Theme System */
:root {
    /* Light Mode - Default */
    color-scheme: light;
    --bg-primary: #ffffff;
    --bg-secondary: #f8f9fa;
    --bg-tertiary: #e9ecef;
    --text-primary: #1a1a1a;
    --text-secondary: #6c757d;
    --text-light: #495057;
    --border-color: #dee2e6;
    --shadow-sm: 0 2px 4px rgba(0,0,0,0.05);
    --shadow-md: 0 4px 12px rgba(0,0,0,0.1);
    --shadow-lg: 0 12px 20px rgba(0,0,0,0.15);
    --navbar-bg: #ffffff;
    --navbar-border: #e9ecef;
    --input-bg: #ffffff;
    --input-border: #dee2e6;
    --input-focus-border: #2563eb;
    --input-focus-ring: rgba(37, 99, 235, 0.1);
    --card-bg: #ffffff;
    --card-border: #e9ecef;
    --hover-bg: #f1f3f5;
    --active-bg: #eff6ff;
    --active-border: #bfdbfe;
    --btn-text: #1a1a1a;
    --link-color: #2563eb;
    --link-hover: #1d4ed8;
    --success: #10b981;
    --warning: #f59e0b;
    --danger: #ef4444;
    --info: #3b82f6;
}

/* Dark Mode */
html[data-theme="dark"] {
    color-scheme: dark;
    --bg-primary: #1f2937;
    --bg-secondary: #111827;
    --bg-tertiary: #374151;
    --text-primary: #f3f4f6;
    --text-secondary: #d1d5db;
    --text-light: #9ca3af;
    --border-color: #4b5563;
    --shadow-sm: 0 2px 4px rgba(0,0,0,0.3);
    --shadow-md: 0 4px 12px rgba(0,0,0,0.4);
    --shadow-lg: 0 12px 20px rgba(0,0,0,0.5);
    --navbar-bg: #111827;
    --navbar-border: #374151;
    --input-bg: #374151;
    --input-border: #4b5563;
    --input-focus-border: #60a5fa;
    --input-focus-ring: rgba(96, 165, 250, 0.1);
    --card-bg: #374151;
    --card-border: #4b5563;
    --hover-bg: #4b5563;
    --active-bg: rgba(37, 99, 235, 0.2);
    --active-border: #3b82f6;
    --btn-text: #f3f4f6;
    --link-color: #60a5fa;
    --link-hover: #93c5fd;
    --success: #34d399;
    --warning: #fbbf24;
    --danger: #f87171;
    --info: #60a5fa;
}

/* Core Element Styling */
html, body {
    background-color: var(--bg-primary);
    color: var(--text-primary);
    transition: background-color 0.3s ease, color 0.3s ease;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    font-size: 0.9375rem;
    line-height: 1.5;
}

h1, h2, h3, h4, h5, h6 {
    color: var(--text-primary);
    font-weight: 600;
}

p {
    color: var(--text-light);
}

a {
    color: var(--link-color);
    transition: color 0.2s ease;
}

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

/* Buttons */
.btn {
    transition: all 0.2s ease;
    border-radius: 0.5rem;
    font-weight: 500;
}

.btn-primary {
    background: linear-gradient(135deg, #2563eb 0%, #1d4ed8 100%) !important;
    border: none !important;
    color: white !important;
}

.btn-primary:hover {
    background: linear-gradient(135deg, #1d4ed8 0%, #1e40af 100%) !important;
    box-shadow: 0 6px 15px rgba(37, 99, 235, 0.4);
    color: white !important;
}

.btn-secondary {
    background-color: var(--bg-tertiary) !important;
    border: 1px solid var(--border-color) !important;
    color: var(--text-primary) !important;
}

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

.btn-sm {
    padding: 0.375rem 0.75rem !important;
    font-size: 0.875rem !important;
}

/* Forms */
.form-control, .form-select {
    background-color: var(--input-bg) !important;
    border: 1px solid var(--input-border) !important;
    color: var(--text-primary) !important;
    border-radius: 0.5rem;
    transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

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

.form-control:focus, .form-select:focus {
    background-color: var(--input-bg) !important;
    border-color: var(--input-focus-border) !important;
    box-shadow: 0 0 0 3px var(--input-focus-ring) !important;
    color: var(--text-primary) !important;
}

.form-label {
    color: var(--text-primary);
    font-weight: 500;
    margin-bottom: 0.5rem;
}

/* Cards */
.card {
    background-color: var(--card-bg) !important;
    border: 1px solid var(--card-border) !important;
    border-radius: 0.75rem;
    box-shadow: var(--shadow-sm);
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

.card-header {
    background-color: var(--bg-secondary) !important;
    border-bottom: 1px solid var(--border-color) !important;
    color: var(--text-primary);
}

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

/* Tables */
.table {
    color: var(--text-primary);
    border-color: var(--border-color);
}

.table th {
    background-color: var(--bg-tertiary);
    color: var(--text-primary);
    font-weight: 600;
    text-transform: uppercase;
    font-size: 0.8rem;
    letter-spacing: 0.5px;
    border-color: var(--border-color);
}

.table tbody tr {
    border-color: var(--border-color);
    transition: background-color 0.15s ease;
}

.table tbody tr:hover {
    background-color: var(--hover-bg);
}

.table-striped > tbody > tr:nth-of-type(odd) {
    background-color: var(--bg-secondary);
}

/* Navbar */
.navbar {
    background-color: var(--navbar-bg) !important;
    border-bottom: 1px solid var(--navbar-border) !important;
    box-shadow: var(--shadow-sm);
}

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

.nav-link {
    color: var(--text-light) !important;
    transition: all 0.2s ease;
    position: relative;
}

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

.nav-link.active {
    color: var(--link-color) !important;
    font-weight: 600;
}

.nav-link.active::after {
    content: '';
    position: absolute;
    bottom: -1.5rem;
    left: 0;
    right: 0;
    height: 3px;
    background-color: var(--link-color);
}

/* Dropdowns */
.dropdown-menu {
    background-color: var(--card-bg) !important;
    border: 1px solid var(--border-color) !important;
    box-shadow: var(--shadow-md);
}

.dropdown-item {
    color: var(--text-primary) !important;
    transition: all 0.2s ease;
}

.dropdown-item:hover {
    background-color: var(--hover-bg) !important;
    color: var(--link-color) !important;
}

.dropdown-item.active {
    background-color: var(--active-bg) !important;
    color: var(--link-color) !important;
}

/* Alerts */
.alert {
    border-radius: 0.5rem;
    border: none;
}

.alert-success {
    background-color: rgba(16, 185, 129, 0.1);
    color: var(--success);
}

.alert-warning {
    background-color: rgba(245, 158, 11, 0.1);
    color: var(--warning);
}

.alert-danger {
    background-color: rgba(239, 68, 68, 0.1);
    color: var(--danger);
}

.alert-info {
    background-color: rgba(59, 130, 246, 0.1);
    color: var(--info);
}

/* Modal */
.modal-content {
    background-color: var(--card-bg) !important;
    border: 1px solid var(--border-color) !important;
}

.modal-header {
    border-bottom: 1px solid var(--border-color) !important;
    background-color: var(--bg-secondary);
}

.modal-footer {
    border-top: 1px solid var(--border-color) !important;
    background-color: var(--bg-secondary);
}

.btn-close {
    filter: invert(1) grayscale(100%) brightness(200%);
}

html[data-theme="dark"] .btn-close {
    filter: invert(0) grayscale(0%) brightness(100%);
}

/* Badges */
.badge {
    font-weight: 600;
    padding: 0.35rem 0.65rem;
    border-radius: 0.3rem;
}

.badge-primary {
    background-color: var(--link-color);
    color: white;
}

.badge-success {
    background-color: var(--success);
    color: white;
}

.badge-warning {
    background-color: var(--warning);
    color: black;
}

.badge-danger {
    background-color: var(--danger);
    color: white;
}

/* Loading Spinner */
.spinner-border {
    border-color: var(--bg-tertiary) !important;
    border-right-color: var(--link-color) !important;
}

/* Pagination */
.pagination {
    display: flex;
    gap: 0.5rem;
}

.page-link {
    background-color: var(--input-bg);
    border: 1px solid var(--input-border);
    color: var(--link-color);
    transition: all 0.2s ease;
}

.page-link:hover {
    background-color: var(--hover-bg);
    border-color: var(--link-color);
}

.page-item.active .page-link {
    background-color: var(--link-color);
    border-color: var(--link-color);
    color: white;
}

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

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

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

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

/* Focus Ring */
:focus-visible {
    outline: 2px solid var(--link-color);
    outline-offset: 2px;
}

button:focus-visible, a:focus-visible {
    outline-offset: 4px;
}

/* Utility Classes */
.text-primary {
    color: var(--text-primary) !important;
}

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

.text-light {
    color: var(--text-light) !important;
}

.bg-light {
    background-color: var(--bg-secondary) !important;
}

.bg-white {
    background-color: var(--card-bg) !important;
}

.border {
    border: 1px solid var(--border-color) !important;
}

.border-top {
    border-top: 1px solid var(--border-color) !important;
}

.border-bottom {
    border-bottom: 1px solid var(--border-color) !important;
}

/* Divider */
hr {
    border-color: var(--border-color);
    opacity: 0.5;
}

/* Code Block */
code, pre {
    background-color: var(--bg-secondary);
    color: var(--text-primary);
    border-radius: 0.25rem;
}

code {
    padding: 0.2rem 0.4rem;
}

pre {
    padding: 1rem;
    overflow-x: auto;
}