/**
 * OLD ENGINES - MAIN STYLESHEET
 * =============================================================================
 * Version: 3.0
 * Author: Old Engines Team
 */

/*-----------------------------------------------------------------------------
| 1. CSS VARIABLES & COLOR SCHEME
-----------------------------------------------------------------------------*/
:root {
    --primary: #003366;      /* Navy Blue */
    --secondary: #FF6600;     /* Orange */
    --accent: #C0C0C0;        /* Silver */
    --white: #FFFFFF;
    --light-gray: #F5F5F5;
    --medium-gray: #E0E0E0;
    --dark-gray: #333333;
    --success: #28A745;
    --warning: #FFC107;
    --danger: #DC3545;
    --info: #17A2B8;
    
    /* Spacing */
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-2xl: 3rem;
    
    /* Layout */
    --border-radius: 4px;
    --transition: all 0.3s ease;
    --container-max-width: 1200px;
    --header-height: 80px;
}

/*-----------------------------------------------------------------------------
| 2. RESET & BASE STYLES
-----------------------------------------------------------------------------*/
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    line-height: 1.6;
    color: var(--dark-gray);
    background-color: var(--white);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/*-----------------------------------------------------------------------------
| 3. CONTAINER & LAYOUT
-----------------------------------------------------------------------------*/
.container {
    width: 100%;
    max-width: var(--container-max-width);
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

/*-----------------------------------------------------------------------------
| 4. TYPOGRAPHY
-----------------------------------------------------------------------------*/
h1, h2, h3, h4, h5, h6 {
    margin-bottom: var(--spacing-md);
    font-weight: 600;
    line-height: 1.3;
    color: var(--primary);
}

h1 { font-size: 2.5rem; }
h2 { font-size: 2rem; }
h3 { font-size: 1.75rem; }
h4 { font-size: 1.5rem; }
h5 { font-size: 1.25rem; }
h6 { font-size: 1rem; }

p {
    margin-bottom: var(--spacing-md);
}

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

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

/*-----------------------------------------------------------------------------
| 5. HEADER & NAVIGATION
-----------------------------------------------------------------------------*/
.site-header {
    background-color: var(--primary);
    color: var(--white);
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: var(--header-height);
}

.logo a {
    color: var(--white);
    font-size: 1.5rem;
    font-weight: bold;
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.logo-icon {
    font-size: 2rem;
}

.logo-text {
    color: var(--white);
}

.logo-text:hover {
    color: var(--secondary);
}

.main-nav ul {
    display: flex;
    list-style: none;
    gap: var(--spacing-lg);
}

.main-nav a {
    color: var(--white);
    font-weight: 500;
    padding: var(--spacing-sm) 0;
    position: relative;
}

.main-nav a:hover {
    color: var(--secondary);
}

.main-nav a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background-color: var(--secondary);
    transition: var(--transition);
}

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

/* Dropdown Menu - Vertical Layout */
.nav-dropdown {
    position: relative;
}

.dropdown-menu {
    position: absolute;
    top: 100%;
    left: 0;
    background-color: var(--white);
    min-width: 200px;
    border-radius: var(--border-radius);
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.15);
    opacity: 0;
    visibility: hidden;
    transform: translateY(-10px);
    transition: var(--transition);
    z-index: 1000;
    padding: 0.5rem 0;
    flex-direction: column !important;
    gap: 0 !important;
}

.nav-dropdown:hover .dropdown-menu {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.dropdown-menu li {
    width: 100%;
    list-style: none;
}

.dropdown-menu li:not(:last-child) {
    border-bottom: 1px solid var(--medium-gray);
}

.dropdown-menu a {
    color: var(--dark-gray);
    padding: 0.75rem 1rem;
    display: block;
    white-space: nowrap;
}

.dropdown-menu a:hover {
    background-color: var(--light-gray);
    color: var(--secondary);
}

.dropdown-menu a::after {
    display: none;
}

.mobile-menu-toggle {
    display: none;
    background: none;
    border: none;
    color: var(--white);
    font-size: 1.5rem;
    cursor: pointer;
}

/*-----------------------------------------------------------------------------
| 6. MAIN CONTENT AREA
-----------------------------------------------------------------------------*/
.site-main {
    flex: 1;
    padding: var(--spacing-2xl) 0;
}

/*-----------------------------------------------------------------------------
| 7. FOOTER
-----------------------------------------------------------------------------*/
.site-footer {
    background-color: var(--primary);
    color: var(--white);
    padding: var(--spacing-2xl) 0 var(--spacing-md);
    margin-top: auto;
}

.footer-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-xl);
    margin-bottom: var(--spacing-xl);
}

.footer-about p {
    color: var(--accent);
}

.footer-links ul {
    list-style: none;
}

.footer-links a {
    color: var(--accent);
    display: inline-block;
    margin-bottom: var(--spacing-sm);
}

.footer-links a:hover {
    color: var(--secondary);
}

.footer-stats ul {
    list-style: none;
}

.footer-stats li {
    color: var(--accent);
    margin-bottom: var(--spacing-sm);
}

.footer-bottom {
    text-align: center;
    padding-top: var(--spacing-lg);
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    color: var(--accent);
}

/*-----------------------------------------------------------------------------
| 8. BUTTONS
-----------------------------------------------------------------------------*/
.btn {
    display: inline-block;
    padding: var(--spacing-sm) var(--spacing-lg);
    border-radius: var(--border-radius);
    font-weight: 500;
    text-align: center;
    cursor: pointer;
    transition: var(--transition);
    border: none;
    font-size: 1rem;
}

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

.btn-primary:hover {
    background-color: #002244;
    color: var(--white);
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(0, 51, 102, 0.3);
}

.btn-secondary {
    background-color: var(--secondary);
    color: var(--white);
}

.btn-secondary:hover {
    background-color: #e65c00;
    color: var(--white);
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(255, 102, 0, 0.3);
}

.btn-outline {
    background-color: transparent;
    border: 2px solid var(--primary);
    color: var(--primary);
}

.btn-outline:hover {
    background-color: var(--primary);
    color: var(--white);
    transform: translateY(-2px);
}

.btn-sm {
    padding: var(--spacing-xs) var(--spacing-sm);
    font-size: 0.875rem;
}

.btn-lg {
    padding: var(--spacing-md) var(--spacing-xl);
    font-size: 1.1rem;
}

/* Quick Filter Buttons - Homepage */
.quick-filters {
    margin-top: 2rem;
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
}

.quick-filter-btn {
    display: inline-block;
    padding: 0.75rem 1.5rem;
    text-decoration: none;
    border-radius: 4px;
    font-weight: 600;
    box-shadow: 0 2px 5px rgba(0,0,0,0.2);
    transition: all 0.3s ease;
}

.quick-filter-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 10px rgba(0,0,0,0.3);
}

.quick-filter-btn.two-stroke {
    background-color: #FF6600;
    color: white;
}

.quick-filter-btn.four-stroke {
    background-color: #003366;
    color: white;
}

.quick-filter-btn.manufacturers {
    background-color: #C0C0C0;
    color: #003366;
}

.quick-filter-btn i {
    margin-right: 0.5rem;
}

/*-----------------------------------------------------------------------------
| 9. CARDS
-----------------------------------------------------------------------------*/
.card {
    background-color: var(--white);
    border-radius: var(--border-radius);
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
    overflow: hidden;
    transition: var(--transition);
}

.card:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.15);
}

.engine-card {
    background-color: var(--white);
    border-radius: var(--border-radius);
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
    overflow: hidden;
    transition: var(--transition);
    height: 100%;
    display: flex;
    flex-direction: column;
    border: 1px solid var(--medium-gray);
}

.engine-card:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 15px rgba(0, 51, 102, 0.2);
    border-color: var(--secondary);
}

.engine-card-header {
    padding: var(--spacing-md);
    background-color: var(--light-gray);
    border-bottom: 3px solid var(--primary);
}

.engine-title {
    margin: 0 0 var(--spacing-xs) 0;
    font-size: 1.25rem;
}

.engine-title a {
    color: var(--primary);
}

.engine-title a:hover {
    color: var(--secondary);
}

.engine-code {
    font-size: 0.875rem;
    color: var(--dark-gray);
    font-family: monospace;
}

.engine-card-body {
    padding: var(--spacing-md);
    flex: 1;
}

.engine-manufacturer {
    display: flex;
    align-items: center;
    gap: 8px;
    margin-bottom: var(--spacing-md);
    padding-bottom: var(--spacing-md);
    border-bottom: 1px solid var(--medium-gray);
    flex-wrap: wrap;
}

.engine-manufacturer i {
    color: var(--secondary);
}

.engine-manufacturer a {
    font-weight: 500;
    color: var(--primary);
}

.engine-manufacturer a:hover {
    color: var(--secondary);
}

.engine-specs {
    display: grid;
    gap: var(--spacing-sm);
}

.spec-item {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-size: 0.9375rem;
}

.spec-item i {
    width: 20px;
    color: var(--secondary);
}

.spec-label {
    color: var(--dark-gray);
    min-width: 90px;
}

.spec-value {
    font-weight: 500;
    color: var(--primary);
}

.engine-card-footer {
    padding: var(--spacing-md);
    background-color: var(--light-gray);
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-top: 1px solid var(--medium-gray);
}

/*-----------------------------------------------------------------------------
| 10. BADGES
-----------------------------------------------------------------------------*/
.stroke-badge, .quality-badge {
    padding: var(--spacing-xs) var(--spacing-sm);
    border-radius: 20px;
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
}

.stroke-badge i, .quality-badge i {
    font-size: 0.625rem;
}

.badge-2stroke {
    background-color: var(--secondary);
    color: var(--white);
}

.badge-4stroke {
    background-color: var(--primary);
    color: var(--white);
}

.badge-unknown {
    background-color: var(--accent);
    color: var(--dark-gray);
}

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

.quality-likely {
    background-color: var(--info);
    color: var(--white);
}

.quality-estimated {
    background-color: var(--warning);
    color: var(--dark-gray);
}

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

.quality-unknown {
    background-color: var(--accent);
    color: var(--dark-gray);
}

/*-----------------------------------------------------------------------------
| 11. BREADCRUMB
-----------------------------------------------------------------------------*/
.breadcrumb {
    margin-bottom: var(--spacing-lg);
}

.breadcrumb ol {
    display: flex;
    list-style: none;
    gap: var(--spacing-sm);
    padding: var(--spacing-sm) 0;
}

.breadcrumb li {
    display: flex;
    align-items: center;
}

.breadcrumb li:not(:last-child)::after {
    content: '/';
    margin-left: var(--spacing-sm);
    color: var(--accent);
}

.breadcrumb a {
    color: var(--primary);
}

.breadcrumb a:hover {
    color: var(--secondary);
}

.breadcrumb [aria-current="page"] {
    color: var(--dark-gray);
    font-weight: 500;
}

/*-----------------------------------------------------------------------------
| 12. PAGINATION
-----------------------------------------------------------------------------*/
.pagination {
    margin-top: var(--spacing-xl);
}

.pagination ul {
    display: flex;
    justify-content: center;
    list-style: none;
    gap: var(--spacing-xs);
}

.pagination a,
.pagination span {
    display: block;
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: var(--border-radius);
    transition: var(--transition);
}

.pagination a {
    background-color: var(--white);
    color: var(--primary);
    border: 1px solid var(--medium-gray);
}

.pagination a:hover {
    background-color: var(--secondary);
    color: var(--white);
    border-color: var(--secondary);
}

.pagination-current {
    background-color: var(--primary);
    color: var(--white);
    border: 1px solid var(--primary);
}

.pagination-ellipsis {
    color: var(--dark-gray);
}

/*-----------------------------------------------------------------------------
| 13. SEARCH FILTERS
-----------------------------------------------------------------------------*/
.search-filters {
    background-color: var(--light-gray);
    padding: var(--spacing-lg);
    border-radius: var(--border-radius);
    margin-bottom: var(--spacing-xl);
    border: 1px solid var(--medium-gray);
}

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

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

.filter-group label {
    display: block;
    margin-bottom: var(--spacing-xs);
    font-weight: 500;
    color: var(--primary);
}

.filter-group select,
.filter-group input {
    width: 100%;
    padding: var(--spacing-sm);
    border: 1px solid var(--medium-gray);
    border-radius: var(--border-radius);
    font-size: 1rem;
}

.filter-group select:focus,
.filter-group input:focus {
    outline: none;
    border-color: var(--secondary);
    box-shadow: 0 0 0 3px rgba(255, 102, 0, 0.1);
}

.filter-actions {
    display: flex;
    gap: var(--spacing-md);
    justify-content: flex-end;
    margin-top: var(--spacing-lg);
}

/*-----------------------------------------------------------------------------
| 14. HERO SECTION
-----------------------------------------------------------------------------*/
.hero {
    background: linear-gradient(135deg, var(--primary), #001f4d);
    color: var(--white);
    padding: var(--spacing-2xl) 0;
    margin-bottom: var(--spacing-2xl);
    border-radius: var(--border-radius);
}

.hero h1 {
    color: var(--white);
    font-size: 3rem;
    margin-bottom: var(--spacing-md);
}

.hero p {
    font-size: 1.25rem;
    margin-bottom: var(--spacing-xl);
    color: var(--accent);
}

/*-----------------------------------------------------------------------------
| 15. SEARCH BAR
-----------------------------------------------------------------------------*/
.search-bar {
    max-width: 600px;
    margin: 0 auto;
}

.search-bar form {
    display: flex;
    gap: var(--spacing-sm);
}

.search-bar input {
    flex: 1;
    padding: var(--spacing-md);
    border: none;
    border-radius: var(--border-radius);
    font-size: 1rem;
}

.search-bar button {
    padding: var(--spacing-md) var(--spacing-xl);
    background-color: var(--secondary);
    color: var(--white);
    border: none;
    border-radius: var(--border-radius);
    cursor: pointer;
    transition: var(--transition);
}

.search-bar button:hover {
    background-color: #e65c00;
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(255, 102, 0, 0.3);
}

/*-----------------------------------------------------------------------------
| 16. STATS CARDS
-----------------------------------------------------------------------------*/
.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-2xl);
}

.stat-card {
    background-color: var(--white);
    border-radius: var(--border-radius);
    padding: var(--spacing-lg);
    text-align: center;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
    transition: var(--transition);
    border: 1px solid var(--medium-gray);
}

.stat-card:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 15px rgba(0, 51, 102, 0.2);
    border-color: var(--secondary);
}

.stat-number {
    font-size: 2.5rem;
    font-weight: bold;
    color: var(--secondary);
    margin-bottom: var(--spacing-xs);
}

.stat-label {
    color: var(--primary);
    font-weight: 500;
}

.stat-icon {
    font-size: 2rem;
    color: var(--accent);
    margin-bottom: var(--spacing-sm);
}

/*-----------------------------------------------------------------------------
| 17. SECTION HEADERS
-----------------------------------------------------------------------------*/
.section-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-lg);
}

.section-header h2 {
    margin: 0;
}

.view-all {
    color: var(--secondary);
    font-weight: 500;
}

.view-all:hover {
    text-decoration: underline;
}

/*-----------------------------------------------------------------------------
| 18. MANUFACTURER GRID & CARDS
-----------------------------------------------------------------------------*/
.manufacturer-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: var(--spacing-lg);
    margin-top: var(--spacing-xl);
}

.manufacturer-card {
    background-color: var(--white);
    border-radius: var(--border-radius);
    padding: var(--spacing-lg);
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
    transition: var(--transition);
    text-align: center;
    border: 1px solid var(--medium-gray);
}

.manufacturer-card:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 15px rgba(0, 51, 102, 0.2);
    border-color: var(--secondary);
}

.manufacturer-card h3 {
    margin-bottom: var(--spacing-sm);
}

.manufacturer-card h3 a {
    color: var(--primary);
}

.manufacturer-card h3 a:hover {
    color: var(--secondary);
}

.manufacturer-country {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    color: var(--dark-gray);
    margin-bottom: var(--spacing-sm);
    font-size: 1rem;
}

.manufacturer-country i {
    color: var(--secondary);
}

.manufacturer-stats {
    display: flex;
    justify-content: center;
    gap: var(--spacing-md);
    margin: var(--spacing-md) 0;
    font-size: 0.875rem;
    color: var(--dark-gray);
}

.manufacturer-stats span {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
}

.manufacturer-stats i {
    color: var(--secondary);
}

/*-----------------------------------------------------------------------------
| 19. ALPHABET FILTER
-----------------------------------------------------------------------------*/
.alphabet-filter {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-xs);
    margin-bottom: var(--spacing-lg);
    justify-content: center;
}

.alphabet-filter a,
.alphabet-filter span {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 36px;
    height: 36px;
    border-radius: var(--border-radius);
    background-color: var(--light-gray);
    color: var(--primary);
    font-weight: 500;
    transition: var(--transition);
    border: 1px solid var(--medium-gray);
}

.alphabet-filter a:hover {
    background-color: var(--secondary);
    color: var(--white);
    border-color: var(--secondary);
}

.alphabet-filter .active {
    background-color: var(--primary);
    color: var(--white);
    border-color: var(--primary);
}

/*-----------------------------------------------------------------------------
| 20. TAB INTERFACE
-----------------------------------------------------------------------------*/
.tabs {
    margin-top: var(--spacing-xl);
}

.tab-nav {
    display: flex;
    gap: var(--spacing-xs);
    border-bottom: 2px solid var(--medium-gray);
    margin-bottom: var(--spacing-lg);
    flex-wrap: wrap;
}

.tab-button {
    padding: var(--spacing-sm) var(--spacing-lg);
    background: none;
    border: none;
    cursor: pointer;
    font-weight: 500;
    color: var(--dark-gray);
    position: relative;
    font-size: 1rem;
}

.tab-button:hover {
    color: var(--secondary);
}

.tab-button.active {
    color: var(--primary);
    font-weight: 600;
}

.tab-button.active::after {
    content: '';
    position: absolute;
    bottom: -2px;
    left: 0;
    right: 0;
    height: 2px;
    background-color: var(--secondary);
}

.tab-pane {
    display: none;
}

.tab-pane.active {
    display: block;
}

/*-----------------------------------------------------------------------------
| 21. TABLE STYLES
-----------------------------------------------------------------------------*/
.data-table {
    width: 100%;
    border-collapse: collapse;
    margin-bottom: var(--spacing-lg);
    background: var(--white);
}

.data-table th,
.data-table td {
    padding: var(--spacing-sm) var(--spacing-md);
    text-align: left;
    border-bottom: 1px solid var(--medium-gray);
}

.data-table th {
    background-color: var(--light-gray);
    color: var(--primary);
    font-weight: 600;
}

.data-table tr:hover {
    background-color: var(--light-gray);
}

/*-----------------------------------------------------------------------------
| 22. FLAG ICONS STYLING
-----------------------------------------------------------------------------*/
.flag-icon {
    border-radius: 3px;
    box-shadow: 0 1px 3px rgba(0,0,0,0.2);
    margin-right: 5px;
    display: inline-block;
    vertical-align: middle;
}

.manufacturer-country .flag-icon {
    font-size: 1.2rem;
    width: 1.5em;
    height: 1.5em;
    line-height: 1.5em;
}

.engine-manufacturer .flag-icon {
    font-size: 1.1rem;
    width: 1.4em;
    height: 1.4em;
    line-height: 1.4em;
}

.country-badge {
    display: inline-flex;
    align-items: center;
    gap: 5px;
    padding: 3px 8px;
    background: var(--light-gray);
    border-radius: 20px;
    font-size: 0.85rem;
    color: var(--dark-gray);
    border: 1px solid var(--medium-gray);
}

.country-badge .flag-icon {
    font-size: 0.9rem;
    width: 1.2em;
    height: 1.2em;
    line-height: 1.2em;
    margin-right: 0;
}

/* Tooltip for country flags */
[class*="flag-icon"] {
    cursor: help;
    position: relative;
}

[class*="flag-icon"]:hover::after {
    content: attr(title);
    position: absolute;
    bottom: 100%;
    left: 50%;
    transform: translateX(-50%);
    background: var(--primary);
    color: white;
    padding: 4px 8px;
    border-radius: 4px;
    font-size: 12px;
    white-space: nowrap;
    z-index: 1000;
    pointer-events: none;
    box-shadow: 0 2px 5px rgba(0,0,0,0.2);
    margin-bottom: 5px;
}

/*-----------------------------------------------------------------------------
| 23. ALERTS & MESSAGES
-----------------------------------------------------------------------------*/
.alert {
    padding: 1rem;
    border-radius: var(--border-radius);
    margin-bottom: 1.5rem;
    border-left: 4px solid transparent;
}

.alert-success {
    background: #d4edda;
    color: #155724;
    border-left-color: var(--success);
}

.alert-error,
.alert-danger {
    background: #f8d7da;
    color: #721c24;
    border-left-color: var(--danger);
}

.alert-warning {
    background: #fff3cd;
    color: #856404;
    border-left-color: var(--warning);
}

.alert-info {
    background: #d1ecf1;
    color: #0c5460;
    border-left-color: var(--info);
}

/*-----------------------------------------------------------------------------
| 24. FORM STYLES
-----------------------------------------------------------------------------*/
.form-group {
    margin-bottom: 1.5rem;
}

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

.form-group input,
.form-group select,
.form-group textarea {
    width: 100%;
    padding: 0.75rem;
    border: 1px solid var(--medium-gray);
    border-radius: var(--border-radius);
    font-size: 1rem;
    font-family: inherit;
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--secondary);
    box-shadow: 0 0 0 3px rgba(255, 102, 0, 0.1);
}

.form-group input[readonly] {
    background-color: var(--light-gray);
    cursor: not-allowed;
}

.form-group small {
    display: block;
    margin-top: 0.25rem;
    color: var(--dark-gray);
    font-size: 0.875rem;
}

/*-----------------------------------------------------------------------------
| 25. ADMIN TABLE ACTIONS
-----------------------------------------------------------------------------*/
.btn-sm {
    padding: 0.25rem 0.5rem;
    font-size: 0.875rem;
}

.btn-sm i {
    font-size: 1rem;
}

.admin-actions {
    display: flex;
    flex-direction: column;
    gap: 0.25rem;
    align-items: center;
}

.admin-actions-row {
    display: flex;
    gap: 0.25rem;
    justify-content: center;
}

/*-----------------------------------------------------------------------------
| 26. DOCUMENT CARDS
-----------------------------------------------------------------------------*/
.document-card {
    background: var(--white);
    border: 1px solid var(--medium-gray);
    border-radius: var(--border-radius);
    padding: 1rem;
    transition: var(--transition);
}

.document-card:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 10px rgba(0,0,0,0.1);
    border-color: var(--secondary);
}

/*-----------------------------------------------------------------------------
| 27. BACKUP UTILITY STYLES
-----------------------------------------------------------------------------*/
.backup-stats {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.backup-file-list {
    background: white;
    border-radius: var(--border-radius);
    overflow: hidden;
}

.backup-file-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem;
    border-bottom: 1px solid var(--medium-gray);
}

.backup-file-item:hover {
    background: var(--light-gray);
}

.backup-actions {
    display: flex;
    gap: 0.5rem;
}

/*-----------------------------------------------------------------------------
| 28. RESPONSIVE DESIGN
-----------------------------------------------------------------------------*/
@media (max-width: 768px) {
    :root {
        --header-height: 60px;
        --spacing-2xl: 2rem;
    }
    
    h1 { font-size: 2rem; }
    h2 { font-size: 1.5rem; }
    h3 { font-size: 1.25rem; }
    
    .mobile-menu-toggle {
        display: block;
    }
    
    .main-nav {
        position: fixed;
        top: var(--header-height);
        left: 0;
        right: 0;
        background-color: var(--primary);
        padding: var(--spacing-md);
        transform: translateY(-100%);
        opacity: 0;
        visibility: hidden;
        transition: var(--transition);
        z-index: 999;
        box-shadow: 0 4px 10px rgba(0,0,0,0.2);
    }
    
    .main-nav.active {
        transform: translateY(0);
        opacity: 1;
        visibility: visible;
    }
    
    .main-nav ul {
        flex-direction: column;
        gap: var(--spacing-md);
    }
    
    .dropdown-menu {
        position: static;
        opacity: 1;
        visibility: visible;
        transform: none;
        box-shadow: none;
        background-color: rgba(255, 255, 255, 0.1);
        margin-top: var(--spacing-sm);
        width: 100%;
        min-width: auto;
    }
    
    .dropdown-menu a {
        color: var(--white);
    }
    
    .dropdown-menu li:not(:last-child) {
        border-bottom-color: rgba(255,255,255,0.2);
    }
    
    .dropdown-menu a:hover {
        background-color: var(--secondary);
        color: var(--white);
    }
    
    .footer-grid {
        grid-template-columns: 1fr;
        gap: var(--spacing-lg);
    }
    
    .stats-grid {
        grid-template-columns: 1fr;
    }
    
    .hero h1 {
        font-size: 2rem;
    }
    
    .search-bar form {
        flex-direction: column;
    }
    
    .filter-grid {
        grid-template-columns: 1fr;
    }
    
    .filter-actions {
        flex-direction: column;
    }
    
    .filter-actions button,
    .filter-actions a {
        width: 100%;
    }
    
    .manufacturer-grid {
        grid-template-columns: 1fr;
    }
    
    .tab-nav {
        flex-wrap: wrap;
    }
    
    .tab-button {
        flex: 1 1 auto;
        text-align: center;
    }
    
    .data-table {
        display: block;
        overflow-x: auto;
    }
    
    .engine-card-footer {
        flex-direction: column;
        gap: var(--spacing-sm);
        align-items: flex-start;
    }
    
    .quick-filters {
        flex-direction: column;
        align-items: stretch;
    }
    
    .quick-filter-btn {
        text-align: center;
    }
    
    .backup-stats {
        grid-template-columns: 1fr;
    }
    
    .backup-file-item {
        flex-direction: column;
        gap: 1rem;
        text-align: center;
    }
}

/*-----------------------------------------------------------------------------
| 29. PRINT STYLES
-----------------------------------------------------------------------------*/
@media print {
    .site-header,
    .site-footer,
    .btn,
    .pagination,
    .search-filters,
    .tab-nav,
    .mobile-menu-toggle,
    .favorite-btn,
    .unit-converter,
    .quick-filters,
    .dropdown-menu {
        display: none !important;
    }
    
    body {
        background-color: white;
        color: black;
        font-size: 12pt;
    }
    
    a {
        color: black;
        text-decoration: underline;
    }
    
    .container {
        max-width: 100%;
        padding: 0;
    }
    
    .engine-card {
        box-shadow: none;
        border: 1px solid #ccc;
        page-break-inside: avoid;
    }
    
    h1, h2, h3 {
        color: black;
    }
    
    .stat-card,
    .manufacturer-card {
        border: 1px solid #ccc;
        box-shadow: none;
    }
}