/* ===================================
   CSS Variables & Reset
   =================================== */
:root {
    /* Colors - Chess Theme */
    --color-primary: #2c3e50;
    --color-secondary: #8b4513;
    --color-accent: #d4af37;
    --color-light: #f8f9fa;
    --color-dark: #1a1a1a;
    --color-white: #ffffff;
    --color-gray: #6c757d;
    --color-gray-light: #e9ecef;
    --color-success: #28a745;
    --color-info: #17a2b8;
    
    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    
    /* Typography */
    --font-primary: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    --font-mono: 'Courier New', monospace;
    
    /* Borders */
    --border-radius: 8px;
    --border-radius-sm: 4px;
    --border-radius-lg: 12px;
    
    /* Shadows */
    --shadow-sm: 0 2px 4px rgba(0,0,0,0.1);
    --shadow-md: 0 4px 6px rgba(0,0,0,0.1);
    --shadow-lg: 0 10px 15px rgba(0,0,0,0.15);
}

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

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

body {
    font-family: var(--font-primary);
    line-height: 1.6;
    color: var(--color-dark);
    background-color: var(--color-light);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

/* ===================================
   Header
   =================================== */
.header {
    background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-secondary) 100%);
    color: var(--color-white);
    padding: var(--spacing-lg) 0;
    box-shadow: var(--shadow-md);
}

.header .container {
    position: relative;
}

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

.logo h1 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: var(--spacing-xs);
}

.tagline {
    font-size: 1rem;
    opacity: 0.9;
}

.header-stats {
    display: flex;
    gap: var(--spacing-lg);
    margin-right: 220px;
}

.stat-item {
    text-align: center;
}

.stat-number {
    display: block;
    font-size: 2rem;
    font-weight: 700;
    color: var(--color-accent);
}

.stat-label {
    display: block;
    font-size: 0.875rem;
    opacity: 0.9;
}

/* Sponsor Logo */
.sponsor-logo {
    position: absolute;
    top: 50%;
    right: 0;
    transform: translateY(-50%);
    cursor: pointer;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    border-radius: 8px;
    overflow: hidden;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}

.sponsor-logo:hover {
    transform: translateY(-50%) scale(1.05);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
}

.sponsor-logo img {
    display: block;
    width: 192px;
    height: 192px;
    object-fit: cover;
}

/* Sponsor Modal */
.sponsor-modal-content {
    max-width: 375px;
    text-align: center;
}

.sponsor-message {
    padding: 2.25rem 1.5rem;
}

.sponsor-message h2 {
    font-size: 1.125rem;
    color: var(--color-text-muted);
    margin-bottom: 1.5rem;
    font-weight: 400;
}

.sponsor-links {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.sponsor-links a {
    font-size: 1.5rem;
    color: var(--color-primary);
    text-decoration: none;
    transition: all 0.3s ease;
    font-weight: 600;
    padding: 0.5rem;
    border-radius: 4px;
}

.sponsor-links a:hover {
    color: var(--color-accent);
    text-decoration: underline;
    background: rgba(212, 175, 55, 0.1);
}

/* ===================================
   Search Section
   =================================== */
.search-section {
    background: var(--color-white);
    padding: var(--spacing-lg) 0;
    box-shadow: var(--shadow-sm);
    position: sticky;
    top: 0;
    z-index: 100;
}

.search-box {
    margin-bottom: var(--spacing-md);
    position: relative;
}

.search-box input {
    width: 100%;
    padding: var(--spacing-md);
    padding-right: 60px;
    font-size: 1.125rem;
    border: 2px solid var(--color-gray-light);
    border-radius: var(--border-radius);
    transition: all 0.3s ease;
}

.search-box input:focus {
    outline: none;
    border-color: var(--color-primary);
    box-shadow: 0 0 0 3px rgba(44, 62, 80, 0.1);
}

.search-btn {
    position: absolute;
    right: 8px;
    top: 50%;
    transform: translateY(-50%);
    background: var(--color-primary);
    color: var(--color-white);
    border: none;
    padding: 0.5rem 1rem;
    border-radius: var(--border-radius);
    cursor: pointer;
    font-size: 1.25rem;
    transition: all 0.3s ease;
}

.search-btn:hover {
    background: var(--color-secondary);
    transform: translateY(-50%) scale(1.05);
}

.filters {
    display: flex;
    gap: var(--spacing-md);
    flex-wrap: wrap;
    align-items: flex-end;
}

.filter-group {
    flex: 1;
    min-width: 200px;
}

.filter-group label {
    display: block;
    font-size: 0.875rem;
    font-weight: 600;
    margin-bottom: var(--spacing-xs);
    color: var(--color-gray);
}

.filter-group select {
    width: 100%;
    padding: var(--spacing-sm);
    font-size: 1rem;
    border: 1px solid var(--color-gray-light);
    border-radius: var(--border-radius-sm);
    background: var(--color-white);
    cursor: pointer;
    transition: border-color 0.3s ease;
}

.filter-group select:focus {
    outline: none;
    border-color: var(--color-primary);
}

.checkbox-group {
    display: flex;
    align-items: center;
}

.checkbox-group label {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    cursor: pointer;
    margin-bottom: 0;
}

.checkbox-group input[type="checkbox"] {
    width: 18px;
    height: 18px;
    cursor: pointer;
}

.btn-random {
    padding: var(--spacing-sm) var(--spacing-md);
    background: var(--color-accent);
    color: var(--color-dark);
    border: none;
    border-radius: var(--border-radius-sm);
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    white-space: nowrap;
}

.btn-random:hover {
    background: #c49b2a;
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.btn-donate {
    background: linear-gradient(135deg, #ff6b6b 0%, #ff5252 100%);
    color: var(--color-white);
    border: none;
    padding: 0.75rem 1.5rem;
    border-radius: var(--border-radius-sm);
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    white-space: nowrap;
    text-decoration: none;
    display: inline-block;
    box-shadow: 0 2px 8px rgba(255, 82, 82, 0.3);
}

.btn-donate:hover {
    background: linear-gradient(135deg, #ff5252 0%, #ff3838 100%);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(255, 82, 82, 0.4);
}

/* ===================================
   Main Content
   =================================== */
.main-content {
    padding: var(--spacing-xl) 0;
    min-height: 60vh;
}

.results-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-lg);
}

.results-header h2 {
    font-size: 1.75rem;
    color: var(--color-primary);
}

#filter-indicator {
    font-size: 1rem;
    color: var(--color-gray);
    font-weight: 400;
}

.btn-clear-filters {
    padding: var(--spacing-xs) var(--spacing-md);
    background: var(--color-gray-light);
    color: var(--color-gray);
    border: none;
    border-radius: var(--border-radius-sm);
    font-size: 0.875rem;
    cursor: pointer;
    transition: all 0.3s ease;
}

.btn-clear-filters:hover {
    background: var(--color-gray);
    color: var(--color-white);
}

/* ===================================
   Loading State
   =================================== */
.loading-state {
    text-align: center;
    padding: var(--spacing-xl);
}

.loader {
    width: 50px;
    height: 50px;
    border: 4px solid var(--color-gray-light);
    border-top-color: var(--color-primary);
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin: 0 auto var(--spacing-md);
}

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

/* ===================================
   Variants Grid
   =================================== */
.variants-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
    gap: var(--spacing-md);
}

.variant-card {
    background: var(--color-white);
    border: 1px solid var(--color-gray-light);
    border-radius: var(--border-radius);
    padding: var(--spacing-md);
    cursor: pointer;
    transition: all 0.3s ease;
}

.variant-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
    border-color: var(--color-primary);
}

.variant-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: var(--spacing-sm);
}

.variant-name {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--color-primary);
    margin-bottom: var(--spacing-xs);
}

.variant-badge {
    background: var(--color-accent);
    color: var(--color-dark);
    padding: 2px 8px;
    border-radius: var(--border-radius-sm);
    font-size: 0.75rem;
    font-weight: 600;
}

.variant-meta {
    display: flex;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-sm);
    font-size: 0.875rem;
    color: var(--color-gray);
}

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

.variant-description {
    color: var(--color-dark);
    line-height: 1.5;
    margin-bottom: var(--spacing-sm);
}

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

.variant-link {
    color: var(--color-info);
    font-size: 0.875rem;
    text-decoration: none;
    font-weight: 600;
}

.variant-link:hover {
    text-decoration: underline;
}

/* ===================================
   Empty State
   =================================== */
.empty-state {
    text-align: center;
    padding: var(--spacing-xl);
}

.empty-icon {
    font-size: 4rem;
    margin-bottom: var(--spacing-md);
    opacity: 0.5;
}

.empty-state h3 {
    font-size: 1.5rem;
    color: var(--color-gray);
    margin-bottom: var(--spacing-sm);
}

.empty-state p {
    color: var(--color-gray);
}

/* ===================================
   Load More
   =================================== */
.load-more-container {
    text-align: center;
    margin-top: var(--spacing-lg);
}

.btn-load-more {
    padding: var(--spacing-md) var(--spacing-xl);
    background: var(--color-primary);
    color: var(--color-white);
    border: none;
    border-radius: var(--border-radius);
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
}

.btn-load-more:hover {
    background: var(--color-secondary);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

/* ===================================
   Modal
   =================================== */
.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 1000;
}

.modal.active {
    display: block;
}

.modal-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.7);
}

.modal-content {
    position: relative;
    max-width: 800px;
    margin: 2rem auto;
    background: var(--color-white);
    border-radius: var(--border-radius-lg);
    box-shadow: var(--shadow-lg);
    max-height: calc(100vh - 4rem);
    overflow-y: auto;
    padding: var(--spacing-xl);
}

.modal-close {
    position: absolute;
    top: var(--spacing-md);
    right: var(--spacing-md);
    width: 40px;
    height: 40px;
    background: var(--color-gray-light);
    border: none;
    border-radius: 50%;
    font-size: 1.5rem;
    cursor: pointer;
    transition: all 0.3s ease;
}

.modal-close:hover {
    background: var(--color-gray);
    color: var(--color-white);
}

/* ===================================
   Footer
   =================================== */
.footer {
    background: var(--color-primary);
    color: var(--color-white);
    padding: var(--spacing-xl) 0 var(--spacing-md);
    margin-top: var(--spacing-xl);
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-lg);
}

.footer-section h3 {
    font-size: 1.5rem;
    margin-bottom: var(--spacing-sm);
}

.footer-section h4 {
    font-size: 1.125rem;
    margin-bottom: var(--spacing-sm);
    color: var(--color-accent);
}

.footer-section p {
    opacity: 0.9;
    margin-bottom: var(--spacing-xs);
}

.footer-section a {
    color: var(--color-accent);
    text-decoration: none;
}

.footer-section a:hover {
    text-decoration: underline;
}

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

.footer-section li {
    padding: var(--spacing-xs) 0;
    opacity: 0.9;
}

.last-updated {
    font-size: 0.875rem;
    opacity: 0.8;
}

.footer-bottom {
    text-align: center;
    padding-top: var(--spacing-md);
    border-top: 1px solid rgba(255, 255, 255, 0.2);
    opacity: 0.8;
}

.donate-btn {
    display: inline-block;
    background: var(--color-accent);
    color: var(--color-dark);
    padding: 0.75rem 1.5rem;
    border-radius: var(--border-radius);
    text-decoration: none;
    font-weight: 600;
    margin-top: 0.5rem;
    transition: all 0.3s ease;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.2);
}

.donate-btn:hover {
    background: #f0c14b;
    transform: translateY(-2px);
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.3);
}

.donate-note {
    font-size: 0.75rem;
    opacity: 0.8;
    margin-top: 0.5rem;
}

/* ===================================
   Responsive Design
   =================================== */
@media (max-width: 768px) {
    .header-content {
        flex-direction: column;
        text-align: center;
    }
    
    .logo h1 {
        font-size: 2rem;
    }
    
    .filters {
        flex-direction: column;
    }
    
    .filter-group {
        width: 100%;
    }
    
    .variants-grid {
        grid-template-columns: 1fr;
    }
    
    .results-header {
        flex-direction: column;
        gap: var(--spacing-sm);
        align-items: flex-start;
    }
    
    .modal-content {
        margin: 1rem;
        padding: var(--spacing-md);
    }
}

@media (max-width: 480px) {
    .logo h1 {
        font-size: 1.5rem;
    }
    
    .stat-number {
        font-size: 1.5rem;
    }
    
    .search-box input {
        font-size: 1rem;
    }
}