:root {
    /* Color Palette */
    --primary-color: #005A9C;
    --secondary-color: #FDB813;
    --dark-color: #1a1a1a;
    --light-color: #f4f4f4;
    --background-color: #ffffff;
    --text-color: #333;
    --heading-color: var(--dark-color);
    --text-muted-color: #6c757d;
    --success-color: #28a745;
    --danger-color: #dc3545;
    --border-color: #dee2e6;
    --surface-accent-color: #e9ecef;

    /* Font System */
    --font-family-base: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji';
    --font-weight-normal: 400;
    --font-weight-medium: 500;
    --font-weight-bold: 700;
    --font-size-base: 1rem;
    --font-size-sm: 0.875rem;
    --font-size-lg: 1.125rem;
    --font-size-h1: 3rem;
    --font-size-h2: 2.5rem;
    --font-size-h3: 1.75rem;
    --font-size-h4: 1.25rem;

    /* Spacing (8px scale) */
    --space-1: 0.25rem;  /* 4px */
    --space-2: 0.5rem;   /* 8px */
    --space-3: 0.75rem;  /* 12px */
    --space-4: 1rem;     /* 16px */
    --space-5: 1.5rem;   /* 24px */
    --space-6: 2rem;     /* 32px */
    --space-7: 2.5rem;   /* 40px */
    --space-8: 4rem;     /* 64px */

    /* UI Properties */
    --border-radius: 8px;
    --box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
    --transition-speed: 0.3s;

    /* Z-Index Scale */
    --z-index-header: 100;
    --z-index-modal: 1000;
    --z-index-command-palette: 2000;
}

[data-theme="dark"] {
    --primary-color: #007bff;
    --secondary-color: #FDB813;
    --dark-color: #f4f4f4;
    --light-color: #121212;
    --background-color: #1e1e1e;
    --text-color: #f4f4f4;
    --heading-color: var(--text-color);
    --text-muted-color: #adb5bd;
    --border-color: #495057;
    --surface-accent-color: #343a40;
    --box-shadow: 0 4px 12px rgba(0, 0, 0, 0.25);
}

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

html,
body {
    height: 100%;
}

body {
    font-family: var(--font-family-base);
    font-size: var(--font-size-base);
    line-height: 1.6;
    background-color: var(--light-color);
    color: var(--text-color);
    display: flex;
    flex-direction: column;
    min-height: 100vh;
    transition: background-color var(--transition-speed) ease, color var(--transition-speed) ease;
}

.container {
    max-width: 1200px;
    margin-inline: auto;
    padding-inline: var(--space-5);
}

h1, h2, h3, h4 {
    line-height: 1.2;
    margin-block-end: var(--space-4);
    color: var(--heading-color);
    font-weight: var(--font-weight-bold);
}

h1 { font-size: var(--font-size-h1); }
h2 { font-size: var(--font-size-h2); }
h3 { font-size: var(--font-size-h3); }
h4 { font-size: var(--font-size-h4); }

h2 {
    text-align: center;
    margin-block-end: var(--space-7);
}

p {
    margin-block-end: var(--space-4);
}

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

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

img {
    max-width: 100%;
    height: auto;
    display: block;
}

/* --- Layout & Sections --- */
header {
    background-color: var(--background-color);
    padding-block: var(--space-4);
    padding-inline: 0;
    box-shadow: var(--box-shadow);
    position: sticky;
    top: 0;
    z-index: var(--z-index-header);
    border-block-end: 1px solid var(--border-color);
    transition: background-color var(--transition-speed) ease;
}

[data-theme="dark"] header {
    border-block-end-color: rgba(255, 255, 255, 0.1);
}

header .navbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: var(--space-4);
}

.logo {
    font-size: 1.8rem;
    font-weight: var(--font-weight-bold);
    color: var(--primary-color);
}

[data-theme="dark"] .logo {
    color: var(--text-color);
}

header nav ul {
    list-style: none;
    display: flex;
    gap: var(--space-5);
}

header nav a {
    font-weight: var(--font-weight-medium);
    font-size: var(--font-size-base);
    padding-block: var(--space-2);
    padding-inline: 0;
}

.header-actions {
    display: flex;
    align-items: center;
    gap: var(--space-3);
}

main {
    flex: 1 0 auto;
}

section {
    padding-block: var(--space-8);
    padding-inline: 0;
}

#hero {
    background-color: var(--dark-color);
    background-image: linear-gradient(rgba(0,0,0,0.6), rgba(0,0,0,0.6)), url('https://images.unsplash.com/photo-1517524206127-48bbd363f5d4?auto=format&fit=crop&w=1920&q=80');
    background-size: cover;
    background-position: center;
    color: #fff;
    text-align: center;
    padding: 6rem var(--space-5);
}

#hero h2 {
    color: #fff;
    font-size: 2.8rem;
    text-shadow: 2px 2px 4px rgba(0,0,0,0.5);
}

#hero p {
    font-size: var(--font-size-lg);
    max-width: 600px;
    margin-inline: auto;
    margin-block-end: var(--space-6);
    text-shadow: 1px 1px 2px rgba(0,0,0,0.5);
}

#events,
#vehicles,
#events-page,
#all-vehicles-page,
#vehicles-page {
    background-color: var(--light-color);
    padding-block-end: var(--space-6);
}

#cta-seller {
    background-color: var(--dark-color);
    color: #fff;
    text-align: center;
    border-radius: var(--border-radius);
    margin-block: var(--space-6);
    margin-inline: auto;
    max-width: 1200px;
}

#cta-seller h2 {
    color: #fff;
}

.section-actions {
    text-align: center;
    margin-block-start: var(--space-7);
}

footer {
    background-color: #111;
    color: #fff;
    text-align: center;
    padding: var(--space-6) 0;
    margin-block-start: auto;
}

.footer-links {
    display: flex;
    justify-content: center;
    gap: var(--space-5);
    margin-block-end: var(--space-4);
    flex-wrap: wrap;
}

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

/* --- Grid & Cards --- */
.grid-container {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--space-5);
}

.grid-container > p {
    grid-column: 1 / -1;
    text-align: center;
    padding: var(--space-6);
    color: var(--text-muted-color);
}

.card {
    background: var(--background-color);
    border-radius: var(--border-radius);
    box-shadow: var(--box-shadow);
    overflow: hidden;
    display: flex;
    flex-direction: column;
    transition: transform var(--transition-speed) ease-in-out, box-shadow var(--transition-speed) ease-in-out;
}

.card:hover, .card:focus-within {
    transform: translateY(-5px);
    box-shadow: 0 8px 16px rgba(0, 0, 0, 0.12);
}

[data-theme="dark"] .card:hover, [data-theme="dark"] .card:focus-within {
    box-shadow: 0 8px 16px rgba(0, 0, 0, 0.3);
}

.card img {
    width: 100%;
    aspect-ratio: 16 / 10;
    object-fit: cover;
}

.event-card .event-details {
    padding: var(--space-5);
    display: flex;
    flex-direction: column;
    flex-grow: 1;
}

.event-card h3 {
    color: var(--primary-color);
    margin-block-end: var(--space-3);
    font-size: var(--font-size-lg);
}

.event-card p {
    margin-block-end: var(--space-2);
    color: var(--text-muted-color);
    font-size: var(--font-size-sm);
}

.event-card .btn {
    margin-block-start: auto;
}

.vehicle-card {
    cursor: pointer;
}

.vehicle-card h4 {
    padding: var(--space-4) var(--space-5) 0;
    font-size: var(--font-size-lg);
    margin-block-end: var(--space-1);
}

.vehicle-card p {
    padding: 0 var(--space-5) var(--space-5);
    margin: 0;
    color: var(--secondary-color);
    font-weight: var(--font-weight-bold);
    font-size: var(--font-size-lg);
}

/* --- UI Components --- */
.event-filter,
.filters {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-4);
    justify-content: center;
    align-items: center;
    padding: var(--space-5);
    border-radius: var(--border-radius);
    max-width: 800px;
    margin-inline: auto;
    margin-block-end: var(--space-7);
}

.event-filter {
    background: rgba(255, 255, 255, 0.1);
}

.filters {
    background: var(--background-color);
    box-shadow: var(--box-shadow);
}

.event-filter input,
.filters input {
    padding: 12px;
    font-size: var(--font-size-base);
    border: 1px solid var(--border-color);
    background-color: var(--background-color);
    color: var(--text-color);
    border-radius: var(--border-radius);
    flex: 1;
    min-width: 180px;
}

[data-theme="dark"] .event-filter input, [data-theme="dark"] .filters input {
    background-color: #333;
}

.btn,
.event-filter button,
#back-to-events {
    background: var(--primary-color);
    color: #fff;
    padding: 12px 24px;
    border: none;
    border-radius: var(--border-radius);
    cursor: pointer;
    font-size: var(--font-size-base);
    font-weight: var(--font-weight-bold);
    text-align: center;
    transition: background-color var(--transition-speed) ease, color var(--transition-speed) ease, transform var(--transition-speed) ease, box-shadow var(--transition-speed) ease;
    display: inline-block;
}

.btn:hover,
.event-filter button:hover,
#back-to-events:hover {
    background: var(--secondary-color);
    color: #111;
    text-decoration: none;
    transform: translateY(-2px);
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.15);
}

.btn-secondary {
    background-color: var(--surface-accent-color);
    color: var(--text-color);
}

.btn-secondary:hover {
    background-color: #dae0e5;
    color: #343a40;
}

[data-theme="dark"] .btn-secondary {
    background-color: var(--surface-accent-color);
    color: var(--text-color);
}

[data-theme="dark"] .btn-secondary:hover {
    background-color: #495057;
}

#back-to-events {
    margin-block-end: var(--space-6);
}

.theme-toggle-btn {
    background: none;
    border: none;
    cursor: pointer;
    font-size: 1.5rem;
    color: var(--text-color);
    transition: color var(--transition-speed) ease, transform var(--transition-speed) ease, background-color var(--transition-speed) ease;
    border-radius: 50%;
    width: 44px;
    height: 44px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
}

.theme-toggle-btn:hover {
    color: var(--primary-color);
    background-color: var(--surface-accent-color);
}

#theme-toggle .moon-icon { display: none; }
[data-theme="dark"] #theme-toggle .sun-icon { display: none; }
[data-theme="dark"] #theme-toggle .moon-icon { display: inline; }

/* Badges */
.verified { color: var(--success-color); font-weight: var(--font-weight-bold); }
.unverified { color: var(--text-muted-color); font-size: 0.9em; }

/* --- Modal --- */
.modal-backdrop {
    position: fixed; inset: 0;
    background-color: rgba(0, 0, 0, 0.8);
    z-index: var(--z-index-modal);
    display: flex; justify-content: center; align-items: center;
    padding: var(--space-5);
    opacity: 0;
    animation: fadeIn 0.3s forwards;
}
@keyframes fadeIn { to { opacity: 1; } }

.modal-content {
    background-color: var(--background-color);
    border-radius: var(--border-radius);
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.3);
    max-width: 800px; width: 100%; max-height: 90vh;
    overflow-y: auto; position: relative;
    padding: var(--space-7);
    transform: scale(0.95);
    animation: scaleIn 0.3s forwards;
}
@keyframes scaleIn { to { transform: scale(1); } }

.modal-content h2 { margin-block-start: 0; text-align: start; }

.modal-close-btn {
    position: absolute; top: 10px; inset-inline-end: 15px;
    background: none; border: none;
    font-size: 2.5rem; color: var(--text-muted-color);
    cursor: pointer; line-height: 1;
    transition: color var(--transition-speed);
}
.modal-close-btn:hover { color: var(--danger-color); }

.modal-gallery {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: var(--space-4);
    margin-block-end: var(--space-6);
}
.modal-gallery img {
    border-radius: var(--border-radius);
    width: 100%; height: 120px; object-fit: cover; aspect-ratio: 4/3;
}

.modal-details p {
    margin-block-end: var(--space-4);
    font-size: var(--font-size-lg);
    line-height: 1.7;
}
.modal-details p strong {
    color: var(--primary-color);
    margin-inline-end: var(--space-2);
}
[data-theme="dark"] .modal-details p strong { color: var(--secondary-color); }

/* --- Skeleton Loaders --- */
.skeleton { opacity: .7; animation: skeleton-loading 1s linear infinite alternate; }
@keyframes skeleton-loading { 0% { background-color: hsl(200, 20%, 80%); } 100% { background-color: hsl(200, 20%, 95%); } }
[data-theme="dark"] .skeleton { animation: skeleton-loading-dark 1s linear infinite alternate; }
@keyframes skeleton-loading-dark { 0% { background-color: #2a2a2a; } 100% { background-color: #3a3a3a; } }
.skeleton-card { cursor: default; pointer-events: none; }
.skeleton-card:hover { transform: none; box-shadow: var(--box-shadow); }
.skeleton-image { height: 0; padding-block-end: 62.5%; /* 16:10 aspect ratio */ }
.skeleton-content { padding: var(--space-5); }
.skeleton-line-md { height: 24px; width: 70%; margin-block-end: var(--space-3); border-radius: 4px; }
.skeleton-line-sm { height: 16px; width: 90%; margin-block-end: var(--space-2); border-radius: 4px; }
.skeleton-line-sm:last-of-type { width: 80%; }
.skeleton-button { height: 45px; width: 120px; margin-block-start: var(--space-5); border-radius: var(--border-radius); }

/* --- Command Palette --- */
.command-palette {
    position: fixed; inset: 0;
    background-color: rgba(0, 0, 0, 0.5);
    z-index: var(--z-index-command-palette);
    display: flex; justify-content: center; align-items: flex-start;
    padding-block-start: 15vh;
}
.command-palette-content {
    background-color: var(--background-color);
    width: 100%; max-width: 600px;
    border-radius: var(--border-radius);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
    overflow: hidden;
}
.command-palette-content input {
    width: 100%; padding: var(--space-4);
    font-size: 1.2rem; border: none;
    border-block-end: 1px solid var(--border-color);
    outline: none; background-color: transparent; color: var(--text-color);
}
.command-palette-results {
    list-style: none; margin: 0; padding: var(--space-2);
    max-height: 40vh; overflow-y: auto;
}
.command-item, .command-item-none { padding: var(--space-3) var(--space-4); border-radius: 6px; }
.command-item {
    display: flex; justify-content: space-between; align-items: center;
    cursor: pointer; transition: background-color var(--transition-speed);
}
.command-item:hover, .command-item:focus-visible { background-color: var(--light-color); outline: none; }
[data-theme="dark"] .command-item:hover, [data-theme="dark"] .command-item:focus-visible { background-color: #333; }
.command-category {
    font-size: 0.8rem; color: var(--text-muted-color);
    background-color: var(--surface-accent-color);
    padding: var(--space-1) var(--space-2); border-radius: 4px;
}
[data-theme="dark"] .command-category { background-color: var(--surface-accent-color); color: var(--text-color); }
.command-item-none { text-align: center; color: var(--text-muted-color); }

/* --- Accessibility --- */
.visually-hidden {
    position: absolute; width: 1px; height: 1px;
    padding: 0; margin: -1px; overflow: hidden;
    clip: rect(0, 0, 0, 0); white-space: nowrap; border: 0;
}
:focus-visible { outline: 3px solid var(--secondary-color); outline-offset: 2px; }
.card:focus-visible { box-shadow: 0 0 0 3px var(--secondary-color); transform: translateY(-5px); }
.btn:focus-visible, .theme-toggle-btn:focus-visible, .modal-close-btn:focus-visible { outline-offset: 4px; }

/* --- Responsive Design --- */
@media (min-width: 768px) {
    .grid-container { grid-template-columns: repeat(2, 1fr); }
}

@media (min-width: 1024px) {
    .grid-container { grid-template-columns: repeat(3, 1fr); }
}

@media (max-width: 600px) {
    :root {
        --font-size-h1: 2.2rem;
        --font-size-h2: 1.8rem;
        --font-size-h3: 1.5rem;
    }
    #hero h2 { font-size: 2.2rem; }
    .event-filter, .filters { flex-direction: column; }
    .event-filter input, .filters input, .event-filter button { width: 100%; }
    .modal-content { padding: var(--space-5); }
    .modal-content h2 { font-size: 1.5rem; }
    header nav { width: 100%; overflow-x: auto; }
    header nav ul { justify-content: flex-start; }
    .header-actions { width: 100%; justify-content: center; }
}