/**
 * CTS Template Kit - Base Stylesheet
 * 
 * Complete CSS foundation with:
 * - CSS Custom Properties (variables)
 * - Light/Dark theme support
 * - Typography scale
 * - Utility classes
 * - Component base styles
 * 
 * @package    CTSTemplateKit
 * @author     Robert Cleaver, Claude AI
 * @version    1.0.0
 * 
 * TABLE OF CONTENTS:
 * 1. CSS Custom Properties
 * 2. Reset & Base
 * 3. Typography
 * 4. Layout Utilities
 * 5. Flexbox & Grid Utilities
 * 6. Spacing Utilities
 * 7. Colors & Backgrounds
 * 8. Borders & Shadows
 * 9. Buttons
 * 10. Forms & Inputs
 * 11. Tables
 * 12. Cards
 * 13. Badges & Pills
 * 14. Alerts
 * 15. Navigation
 * 16. Modals
 * 17. Loading States
 * 18. Print Styles
 */

/* =============================================================================
   1. CSS Custom Properties
   ============================================================================= */

:root {
    /* Brand Colors */
    --color-primary: #1a2b5a;
    --color-primary-light: #2a3d6e;
    --color-primary-dark: #0f1a38;
    --color-accent: #c41230;
    --color-accent-light: #e63950;
    --color-accent-dark: #9e0f27;
    
    /* Neutral Colors */
    --color-white: #ffffff;
    --color-gray-50: #f9fafb;
    --color-gray-100: #f3f4f6;
    --color-gray-200: #e5e7eb;
    --color-gray-300: #d1d5db;
    --color-gray-400: #9ca3af;
    --color-gray-500: #6b7280;
    --color-gray-600: #4b5563;
    --color-gray-700: #374151;
    --color-gray-800: #1f2937;
    --color-gray-900: #111827;
    --color-black: #000000;
    
    /* Semantic Colors */
    --color-success: #10b981;
    --color-success-light: #d1fae5;
    --color-success-dark: #059669;
    --color-warning: #f59e0b;
    --color-warning-light: #fef3c7;
    --color-warning-dark: #d97706;
    --color-danger: #ef4444;
    --color-danger-light: #fee2e2;
    --color-danger-dark: #dc2626;
    --color-info: #3b82f6;
    --color-info-light: #dbeafe;
    --color-info-dark: #2563eb;
    
    /* Special Colors */
    --color-star: #fbbf24;
    --color-star-empty: #d1d5db;
    --color-link: #2563eb;
    --color-link-hover: #1d4ed8;
    
    /* Typography */
    --font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    --font-family-mono: 'SF Mono', Monaco, 'Cascadia Code', 'Roboto Mono', Consolas, monospace;
    --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;
    --line-height: 1.5;
    --line-height-tight: 1.25;
    --line-height-loose: 1.75;
    
    /* 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;
    
    /* Border Radius */
    --radius-none: 0;
    --radius-sm: 0.25rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    --radius-full: 9999px;
    
    /* Shadows */
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
    
    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-base: 200ms ease;
    --transition-slow: 300ms ease;
    
    /* Z-Index Scale */
    --z-dropdown: 100;
    --z-sticky: 200;
    --z-fixed: 300;
    --z-modal-backdrop: 400;
    --z-modal: 500;
    --z-toast: 600;
    
    /* Light Theme Semantic (default) */
    --bg-primary: var(--color-gray-100);
    --bg-secondary: var(--color-white);
    --bg-tertiary: var(--color-gray-50);
    --text-primary: var(--color-gray-900);
    --text-secondary: var(--color-gray-600);
    --text-muted: var(--color-gray-400);
    --border-color: var(--color-gray-200);
    --input-bg: var(--color-white);
    --input-border: var(--color-gray-300);
}

/* Dark Theme */
[data-theme="dark"] {
    --bg-primary: #111827;
    --bg-secondary: #1f2937;
    --bg-tertiary: #374151;
    --text-primary: #f3f4f6;
    --text-secondary: #9ca3af;
    --text-muted: #6b7280;
    --border-color: #374151;
    --input-bg: #1f2937;
    --input-border: #4b5563;
    --color-accent: #e63950;
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.5);
}

/* =============================================================================
   2. Reset & Base
   ============================================================================= */

*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    font-size: 16px;
    -webkit-text-size-adjust: 100%;
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-family);
    font-size: var(--font-size-base);
    line-height: var(--line-height);
    color: var(--text-primary);
    background-color: var(--bg-primary);
    min-height: 100vh;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

img, picture, video, canvas, svg {
    display: block;
    max-width: 100%;
}

input, button, textarea, select {
    font: inherit;
}

a {
    color: var(--color-link);
    text-decoration: none;
    transition: color var(--transition-fast);
}

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

/* =============================================================================
   3. Typography
   ============================================================================= */

h1, h2, h3, h4, h5, h6 {
    font-weight: 600;
    line-height: var(--line-height-tight);
    color: var(--text-primary);
    margin-bottom: var(--spacing-sm);
}

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-bottom: var(--spacing-md);
}

.text-xs { font-size: var(--font-size-xs); }
.text-sm { font-size: var(--font-size-sm); }
.text-base { font-size: var(--font-size-base); }
.text-lg { font-size: var(--font-size-lg); }
.text-xl { font-size: var(--font-size-xl); }
.text-2xl { font-size: var(--font-size-2xl); }
.text-3xl { font-size: var(--font-size-3xl); }
.text-4xl { font-size: var(--font-size-4xl); }

.font-normal { font-weight: 400; }
.font-medium { font-weight: 500; }
.font-semibold { font-weight: 600; }
.font-bold { font-weight: 700; }

.text-left { text-align: left; }
.text-center { text-align: center; }
.text-right { text-align: right; }

.uppercase { text-transform: uppercase; }
.lowercase { text-transform: lowercase; }
.capitalize { text-transform: capitalize; }

.truncate {
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.mono { font-family: var(--font-family-mono); }

/* =============================================================================
   4. Layout Utilities
   ============================================================================= */

.container {
    width: 100%;
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

.container-sm { max-width: 640px; }
.container-md { max-width: 768px; }
.container-lg { max-width: 1024px; }
.container-xl { max-width: 1280px; }
.container-full { max-width: 100%; }

.w-full { width: 100%; }
.h-full { height: 100%; }
.min-h-screen { min-height: 100vh; }

.hidden { display: none; }
.block { display: block; }
.inline { display: inline; }
.inline-block { display: inline-block; }

.overflow-hidden { overflow: hidden; }
.overflow-auto { overflow: auto; }
.overflow-x-auto { overflow-x: auto; }
.overflow-y-auto { overflow-y: auto; }

/* =============================================================================
   5. Flexbox & Grid Utilities
   ============================================================================= */

.flex { display: flex; }
.inline-flex { display: inline-flex; }
.flex-col { flex-direction: column; }
.flex-row { flex-direction: row; }
.flex-wrap { flex-wrap: wrap; }
.flex-nowrap { flex-wrap: nowrap; }

.items-start { align-items: flex-start; }
.items-center { align-items: center; }
.items-end { align-items: flex-end; }
.items-stretch { align-items: stretch; }

.justify-start { justify-content: flex-start; }
.justify-center { justify-content: center; }
.justify-end { justify-content: flex-end; }
.justify-between { justify-content: space-between; }
.justify-around { justify-content: space-around; }

.flex-1 { flex: 1 1 0%; }
.flex-auto { flex: 1 1 auto; }
.flex-none { flex: none; }

.gap-xs { gap: var(--spacing-xs); }
.gap-sm { gap: var(--spacing-sm); }
.gap-md { gap: var(--spacing-md); }
.gap-lg { gap: var(--spacing-lg); }
.gap-xl { gap: var(--spacing-xl); }

.grid { display: grid; }
.grid-cols-1 { grid-template-columns: repeat(1, minmax(0, 1fr)); }
.grid-cols-2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid-cols-3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid-cols-4 { grid-template-columns: repeat(4, minmax(0, 1fr)); }

/* =============================================================================
   6. Spacing Utilities
   ============================================================================= */

/* Margin */
.m-0 { margin: 0; }
.m-xs { margin: var(--spacing-xs); }
.m-sm { margin: var(--spacing-sm); }
.m-md { margin: var(--spacing-md); }
.m-lg { margin: var(--spacing-lg); }
.m-xl { margin: var(--spacing-xl); }
.m-auto { margin: auto; }

.mt-0 { margin-top: 0; }
.mt-xs { margin-top: var(--spacing-xs); }
.mt-sm { margin-top: var(--spacing-sm); }
.mt-md { margin-top: var(--spacing-md); }
.mt-lg { margin-top: var(--spacing-lg); }
.mt-xl { margin-top: var(--spacing-xl); }

.mb-0 { margin-bottom: 0; }
.mb-xs { margin-bottom: var(--spacing-xs); }
.mb-sm { margin-bottom: var(--spacing-sm); }
.mb-md { margin-bottom: var(--spacing-md); }
.mb-lg { margin-bottom: var(--spacing-lg); }
.mb-xl { margin-bottom: var(--spacing-xl); }

.ml-0 { margin-left: 0; }
.ml-xs { margin-left: var(--spacing-xs); }
.ml-sm { margin-left: var(--spacing-sm); }
.ml-md { margin-left: var(--spacing-md); }
.ml-auto { margin-left: auto; }

.mr-0 { margin-right: 0; }
.mr-xs { margin-right: var(--spacing-xs); }
.mr-sm { margin-right: var(--spacing-sm); }
.mr-md { margin-right: var(--spacing-md); }
.mr-auto { margin-right: auto; }

.mx-auto { margin-left: auto; margin-right: auto; }
.my-md { margin-top: var(--spacing-md); margin-bottom: var(--spacing-md); }
.my-lg { margin-top: var(--spacing-lg); margin-bottom: var(--spacing-lg); }

/* Padding */
.p-0 { padding: 0; }
.p-xs { padding: var(--spacing-xs); }
.p-sm { padding: var(--spacing-sm); }
.p-md { padding: var(--spacing-md); }
.p-lg { padding: var(--spacing-lg); }
.p-xl { padding: var(--spacing-xl); }

.pt-0 { padding-top: 0; }
.pt-md { padding-top: var(--spacing-md); }
.pt-lg { padding-top: var(--spacing-lg); }

.pb-0 { padding-bottom: 0; }
.pb-md { padding-bottom: var(--spacing-md); }
.pb-lg { padding-bottom: var(--spacing-lg); }

.px-md { padding-left: var(--spacing-md); padding-right: var(--spacing-md); }
.px-lg { padding-left: var(--spacing-lg); padding-right: var(--spacing-lg); }

.py-sm { padding-top: var(--spacing-sm); padding-bottom: var(--spacing-sm); }
.py-md { padding-top: var(--spacing-md); padding-bottom: var(--spacing-md); }
.py-lg { padding-top: var(--spacing-lg); padding-bottom: var(--spacing-lg); }

/* =============================================================================
   7. Colors & Backgrounds
   ============================================================================= */

/* Text Colors */
.text-primary { color: var(--text-primary); }
.text-secondary { color: var(--text-secondary); }
.text-muted { color: var(--text-muted); }
.text-accent { color: var(--color-accent); }
.text-brand { color: var(--color-primary); }
.text-white { color: var(--color-white); }
.text-success { color: var(--color-success); }
.text-warning { color: var(--color-warning); }
.text-danger { color: var(--color-danger); }
.text-info { color: var(--color-info); }

/* Background Colors */
.bg-primary { background-color: var(--bg-primary); }
.bg-secondary { background-color: var(--bg-secondary); }
.bg-tertiary { background-color: var(--bg-tertiary); }
.bg-white { background-color: var(--color-white); }
.bg-brand { background-color: var(--color-primary); }
.bg-accent { background-color: var(--color-accent); }
.bg-success { background-color: var(--color-success); }
.bg-success-light { background-color: var(--color-success-light); }
.bg-warning { background-color: var(--color-warning); }
.bg-warning-light { background-color: var(--color-warning-light); }
.bg-danger { background-color: var(--color-danger); }
.bg-danger-light { background-color: var(--color-danger-light); }
.bg-info { background-color: var(--color-info); }
.bg-info-light { background-color: var(--color-info-light); }

/* =============================================================================
   8. Borders & Shadows
   ============================================================================= */

.border { border: 1px solid var(--border-color); }
.border-t { border-top: 1px solid var(--border-color); }
.border-b { border-bottom: 1px solid var(--border-color); }
.border-l { border-left: 1px solid var(--border-color); }
.border-r { border-right: 1px solid var(--border-color); }
.border-0 { border: none; }

.border-primary { border-color: var(--color-primary); }
.border-accent { border-color: var(--color-accent); }
.border-success { border-color: var(--color-success); }
.border-warning { border-color: var(--color-warning); }
.border-danger { border-color: var(--color-danger); }

.rounded-none { border-radius: var(--radius-none); }
.rounded-sm { border-radius: var(--radius-sm); }
.rounded { border-radius: var(--radius-md); }
.rounded-lg { border-radius: var(--radius-lg); }
.rounded-xl { border-radius: var(--radius-xl); }
.rounded-full { border-radius: var(--radius-full); }

.shadow-none { box-shadow: none; }
.shadow-sm { box-shadow: var(--shadow-sm); }
.shadow { box-shadow: var(--shadow-md); }
.shadow-lg { box-shadow: var(--shadow-lg); }
.shadow-xl { box-shadow: var(--shadow-xl); }

/* =============================================================================
   9. Buttons
   ============================================================================= */

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
    padding: 0.625rem 1.25rem;
    font-size: var(--font-size-sm);
    font-weight: 500;
    line-height: 1;
    text-align: center;
    text-decoration: none;
    border: 1px solid transparent;
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all var(--transition-fast);
    white-space: nowrap;
}

.btn:focus {
    outline: none;
    box-shadow: 0 0 0 3px rgba(26, 43, 90, 0.2);
}

.btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.btn-primary {
    background-color: var(--color-primary);
    color: var(--color-white);
}
.btn-primary:hover:not(:disabled) {
    background-color: var(--color-primary-dark);
    color: var(--color-white);
    text-decoration: none;
}

.btn-accent {
    background-color: var(--color-accent);
    color: var(--color-white);
}
.btn-accent:hover:not(:disabled) {
    background-color: var(--color-accent-dark);
    color: var(--color-white);
    text-decoration: none;
}

.btn-secondary {
    background-color: var(--bg-secondary);
    color: var(--text-primary);
    border-color: var(--border-color);
}
.btn-secondary:hover:not(:disabled) {
    background-color: var(--bg-tertiary);
    color: var(--text-primary);
    text-decoration: none;
}

.btn-success {
    background-color: var(--color-success);
    color: var(--color-white);
}
.btn-success:hover:not(:disabled) {
    background-color: var(--color-success-dark);
}

.btn-danger {
    background-color: var(--color-danger);
    color: var(--color-white);
}
.btn-danger:hover:not(:disabled) {
    background-color: var(--color-danger-dark);
}

.btn-ghost {
    background-color: transparent;
    color: var(--text-primary);
}
.btn-ghost:hover:not(:disabled) {
    background-color: var(--bg-tertiary);
    text-decoration: none;
}

.btn-link {
    background: none;
    border: none;
    color: var(--color-link);
    padding: 0;
}
.btn-link:hover:not(:disabled) {
    color: var(--color-link-hover);
    text-decoration: underline;
}

.btn-sm {
    padding: 0.375rem 0.75rem;
    font-size: var(--font-size-xs);
}

.btn-lg {
    padding: 0.875rem 1.75rem;
    font-size: var(--font-size-base);
}

.btn-icon {
    padding: 0.5rem;
    line-height: 1;
}

.btn-icon svg {
    width: 1.25rem;
    height: 1.25rem;
}

/* =============================================================================
   10. Forms & Inputs
   ============================================================================= */

.form-group {
    margin-bottom: var(--spacing-md);
}

.form-label {
    display: block;
    margin-bottom: var(--spacing-xs);
    font-size: var(--font-size-sm);
    font-weight: 500;
    color: var(--text-primary);
}

.form-label-required::after {
    content: ' *';
    color: var(--color-danger);
}

.form-input,
.form-select,
.form-textarea {
    display: block;
    width: 100%;
    padding: 0.625rem 0.875rem;
    font-size: var(--font-size-base);
    line-height: var(--line-height);
    color: var(--text-primary);
    background-color: var(--input-bg);
    border: 1px solid var(--input-border);
    border-radius: var(--radius-md);
    transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.form-input:focus,
.form-select:focus,
.form-textarea:focus {
    outline: none;
    border-color: var(--color-primary);
    box-shadow: 0 0 0 3px rgba(26, 43, 90, 0.1);
}

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

.form-input:disabled,
.form-select:disabled {
    background-color: var(--bg-tertiary);
    cursor: not-allowed;
}

.form-input.is-invalid,
.form-select.is-invalid {
    border-color: var(--color-danger);
}

.form-input.is-invalid:focus {
    box-shadow: 0 0 0 3px rgba(239, 68, 68, 0.1);
}

.form-textarea {
    min-height: 100px;
    resize: vertical;
}

.form-select {
    appearance: none;
    background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' fill='none' viewBox='0 0 20 20'%3e%3cpath stroke='%236b7280' stroke-linecap='round' stroke-linejoin='round' stroke-width='1.5' d='M6 8l4 4 4-4'/%3e%3c/svg%3e");
    background-position: right 0.5rem center;
    background-repeat: no-repeat;
    background-size: 1.5em 1.5em;
    padding-right: 2.5rem;
}

.form-checkbox,
.form-radio {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-sm);
    cursor: pointer;
}

.form-checkbox input,
.form-radio input {
    width: 1rem;
    height: 1rem;
    accent-color: var(--color-primary);
}

.form-help {
    margin-top: var(--spacing-xs);
    font-size: var(--font-size-sm);
    color: var(--text-muted);
}

.form-error {
    margin-top: var(--spacing-xs);
    font-size: var(--font-size-sm);
    color: var(--color-danger);
}

.form-row {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--spacing-md);
}

/* =============================================================================
   11. Tables
   ============================================================================= */

.table-container {
    width: 100%;
    overflow-x: auto;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
}

.table {
    width: 100%;
    border-collapse: collapse;
    font-size: var(--font-size-sm);
}

.table th,
.table td {
    padding: 0.75rem 1rem;
    text-align: left;
    vertical-align: middle;
    border-bottom: 1px solid var(--border-color);
}

.table th {
    font-weight: 600;
    color: var(--text-primary);
    background-color: var(--bg-tertiary);
    white-space: nowrap;
}

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

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

.table tbody tr:last-child td {
    border-bottom: none;
}

.table-striped tbody tr:nth-child(even) {
    background-color: var(--bg-tertiary);
}

.table th.sortable {
    cursor: pointer;
    user-select: none;
}

.table th.sortable:hover {
    background-color: var(--bg-primary);
}

.table td.numeric {
    text-align: right;
    font-variant-numeric: tabular-nums;
}

/* =============================================================================
   12. Cards
   ============================================================================= */

.card {
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
}

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

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

.card-body {
    padding: var(--spacing-lg);
}

.card-footer {
    padding: var(--spacing-md) var(--spacing-lg);
    border-top: 1px solid var(--border-color);
    background-color: var(--bg-tertiary);
    border-radius: 0 0 var(--radius-lg) var(--radius-lg);
}

.card-flush {
    border: none;
    box-shadow: none;
}

/* =============================================================================
   13. Badges & Pills
   ============================================================================= */

.badge {
    display: inline-flex;
    align-items: center;
    padding: 0.25rem 0.625rem;
    font-size: var(--font-size-xs);
    font-weight: 600;
    line-height: 1;
    border-radius: var(--radius-full);
    white-space: nowrap;
}

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

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

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

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

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

.badge-info {
    background-color: var(--color-info-light);
    color: var(--color-info-dark);
}

.badge-gray {
    background-color: var(--color-gray-200);
    color: var(--color-gray-700);
}

/* =============================================================================
   14. Alerts
   ============================================================================= */

.alert {
    padding: var(--spacing-md) var(--spacing-lg);
    border-radius: var(--radius-md);
    border-left: 4px solid;
    margin-bottom: var(--spacing-md);
}

.alert-success {
    background-color: var(--color-success-light);
    border-color: var(--color-success);
    color: var(--color-success-dark);
}

.alert-warning {
    background-color: var(--color-warning-light);
    border-color: var(--color-warning);
    color: var(--color-warning-dark);
}

.alert-danger {
    background-color: var(--color-danger-light);
    border-color: var(--color-danger);
    color: var(--color-danger-dark);
}

.alert-info {
    background-color: var(--color-info-light);
    border-color: var(--color-info);
    color: var(--color-info-dark);
}

.alert-title {
    font-weight: 600;
    margin-bottom: var(--spacing-xs);
}

/* =============================================================================
   15. Navigation
   ============================================================================= */

.nav-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--spacing-md) var(--spacing-lg);
    background-color: var(--bg-secondary);
    border-bottom: 1px solid var(--border-color);
    box-shadow: var(--shadow-sm);
    position: sticky;
    top: 0;
    z-index: var(--z-sticky);
}

.nav-brand {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

.nav-brand img {
    height: 40px;
    width: auto;
}

.nav-brand-text {
    font-size: var(--font-size-xl);
    font-weight: 700;
    color: var(--text-primary);
}

.nav-menu {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    list-style: none;
}

.nav-link {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-sm) var(--spacing-md);
    color: var(--text-secondary);
    border-radius: var(--radius-md);
    transition: all var(--transition-fast);
}

.nav-link:hover {
    background-color: var(--bg-tertiary);
    color: var(--text-primary);
    text-decoration: none;
}

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

/* Settings Dropdown */
.dropdown {
    position: relative;
}

.dropdown-menu {
    position: absolute;
    top: 100%;
    right: 0;
    margin-top: var(--spacing-xs);
    min-width: 200px;
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    z-index: var(--z-dropdown);
    display: none;
}

.dropdown-menu.active {
    display: block;
}

.dropdown-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--spacing-sm) var(--spacing-md);
    color: var(--text-primary);
    cursor: pointer;
    transition: background-color var(--transition-fast);
}

.dropdown-item:hover {
    background-color: var(--bg-tertiary);
}

.dropdown-item:first-child {
    border-radius: var(--radius-lg) var(--radius-lg) 0 0;
}

.dropdown-item:last-child {
    border-radius: 0 0 var(--radius-lg) var(--radius-lg);
}

.dropdown-divider {
    height: 1px;
    background-color: var(--border-color);
    margin: var(--spacing-xs) 0;
}

/* Theme Toggle Switch */
.theme-toggle {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.toggle-switch {
    position: relative;
    width: 44px;
    height: 24px;
    background-color: var(--color-gray-300);
    border-radius: var(--radius-full);
    cursor: pointer;
    transition: background-color var(--transition-base);
}

.toggle-switch.active {
    background-color: var(--color-primary);
}

.toggle-switch::after {
    content: '';
    position: absolute;
    top: 2px;
    left: 2px;
    width: 20px;
    height: 20px;
    background-color: var(--color-white);
    border-radius: 50%;
    transition: transform var(--transition-base);
}

.toggle-switch.active::after {
    transform: translateX(20px);
}

/* =============================================================================
   16. Modals
   ============================================================================= */

.modal-backdrop {
    position: fixed;
    inset: 0;
    background-color: rgba(0, 0, 0, 0.5);
    z-index: var(--z-modal-backdrop);
    display: none;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-lg);
}

.modal-backdrop.active {
    display: flex;
}

.modal {
    width: 100%;
    max-width: 500px;
    max-height: 90vh;
    background-color: var(--bg-secondary);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-xl);
    overflow: hidden;
    display: flex;
    flex-direction: column;
}

.modal-lg { max-width: 800px; }
.modal-sm { max-width: 400px; }

.modal-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--spacing-lg);
    border-bottom: 1px solid var(--border-color);
}

.modal-title {
    font-size: var(--font-size-xl);
    font-weight: 600;
    margin: 0;
}

.modal-close {
    background: none;
    border: none;
    padding: var(--spacing-xs);
    color: var(--text-muted);
    cursor: pointer;
    border-radius: var(--radius-md);
    transition: all var(--transition-fast);
}

.modal-close:hover {
    background-color: var(--bg-tertiary);
    color: var(--text-primary);
}

.modal-body {
    padding: var(--spacing-lg);
    overflow-y: auto;
}

.modal-footer {
    display: flex;
    justify-content: flex-end;
    gap: var(--spacing-sm);
    padding: var(--spacing-md) var(--spacing-lg);
    border-top: 1px solid var(--border-color);
    background-color: var(--bg-tertiary);
}

/* =============================================================================
   17. Loading States
   ============================================================================= */

.loading-overlay {
    position: fixed;
    inset: 0;
    background-color: rgba(255, 255, 255, 0.8);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: var(--z-modal);
}

[data-theme="dark"] .loading-overlay {
    background-color: rgba(17, 24, 39, 0.8);
}

.spinner {
    width: 40px;
    height: 40px;
    border: 3px solid var(--color-gray-200);
    border-top-color: var(--color-primary);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

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

.skeleton {
    background: linear-gradient(90deg, var(--color-gray-200) 25%, var(--color-gray-100) 50%, var(--color-gray-200) 75%);
    background-size: 200% 100%;
    animation: skeleton-loading 1.5s infinite;
    border-radius: var(--radius-sm);
}

@keyframes skeleton-loading {
    0% { background-position: 200% 0; }
    100% { background-position: -200% 0; }
}

/* =============================================================================
   18. Print Styles
   ============================================================================= */

@media print {
    body {
        background: white;
        color: black;
        font-size: 12pt;
    }
    
    .no-print {
        display: none !important;
    }
    
    .nav-header,
    .modal-backdrop,
    .loading-overlay {
        display: none !important;
    }
    
    .card {
        border: 1px solid #ccc;
        box-shadow: none;
        break-inside: avoid;
    }
    
    a {
        color: black;
        text-decoration: underline;
    }
    
    .btn {
        border: 1px solid #ccc;
    }
}

/* =============================================================================
   Responsive Breakpoints
   ============================================================================= */

@media (max-width: 768px) {
    .container {
        padding: 0 var(--spacing-sm);
    }
    
    .nav-header {
        flex-wrap: wrap;
        gap: var(--spacing-sm);
    }
    
    .form-row {
        grid-template-columns: 1fr;
    }
    
    .table-container {
        font-size: var(--font-size-xs);
    }
    
    .hidden-mobile {
        display: none !important;
    }
}

@media (min-width: 769px) {
    .hidden-desktop {
        display: none !important;
    }
}