:root {
    --primary-color: #0078d4;
    --primary-hover: #106ebe;
    --background-color: #f3f2f1;
    --surface-color: #ffffff;
    --card-background: #ffffff;
    --text-primary: #323130;
    --text-secondary: #605e5c;
    --border-color: #e1dfdd;
    --danger-color: #d13438;
    --shadow-color: rgba(0, 0, 0, 0.1);
}

/* Dark Theme */
[data-theme="dark"] {
    --primary-color: #4da6ff;
    --primary-hover: #7bbfff;
    --background-color: #1a1a1a;
    --surface-color: #2d2d2d;
    --card-background: #2d2d2d;
    --text-primary: #f0f0f0;
    --text-secondary: #b0b0b0;
    --border-color: #404040;
    --danger-color: #ff6b6b;
    --shadow-color: rgba(0, 0, 0, 0.3);
}

/* System preference fallback */
@media (prefers-color-scheme: dark) {
    :root:not([data-theme="light"]) {
        --primary-color: #4da6ff;
        --primary-hover: #7bbfff;
        --background-color: #1a1a1a;
        --surface-color: #2d2d2d;
        --card-background: #2d2d2d;
        --text-primary: #f0f0f0;
        --text-secondary: #b0b0b0;
        --border-color: #404040;
        --danger-color: #ff6b6b;
        --shadow-color: rgba(0, 0, 0, 0.3);
    }
}

body {
    font-family: 'Segoe UI', 'Segoe UI Web (West European)', 'Segoe UI', -apple-system, BlinkMacSystemFont, Roboto, 'Helvetica Neue', sans-serif;
    margin: 0;
    padding: 0;
    background-color: var(--background-color);
    color: var(--text-primary);
    display: flex;
    flex-direction: column;
    height: 100vh;
}

/* App Bar */
header {
    background-color: var(--primary-color);
    color: white;
    padding: 10px 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
    z-index: 1000;
}

header h1 {
    margin: 0;
    font-size: 1.25rem;
    font-weight: 600;
}

.menu-btn {
    background: none;
    border: none;
    color: white;
    font-size: 1.5rem;
    cursor: pointer;
    padding: 5px;
}

/* Drawer Menu */
.drawer {
    position: fixed;
    top: 0;
    right: -250px;
    width: 250px;
    height: 100%;
    background-color: var(--surface-color);
    box-shadow: -2px 0 5px var(--shadow-color);
    transition: right 0.3s ease;
    z-index: 1100;
    padding-top: 60px;
}

.drawer.open {
    right: 0;
}

.drawer a {
    display: block;
    padding: 15px 20px;
    text-decoration: none;
    color: var(--text-primary);
    border-bottom: 1px solid var(--border-color);
}

.drawer-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.5);
    display: none;
    z-index: 1050;
}

.drawer-overlay.open {
    display: block;
}

/* Filters Section */
.filters {
    background-color: var(--surface-color);
    padding: 15px;
    border-bottom: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.filter-row {
    display: flex;
    gap: 10px;
    flex-wrap: wrap;
}

.filter-row>* {
    flex: 1;
}

input,
select {
    padding: 8px;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    font-size: 1rem;
}

.btn {
    padding: 8px 16px;
    background-color: var(--primary-color);
    color: white;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    font-weight: 600;
}

.btn-secondary {
    background-color: var(--surface-color);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
}

/* Main Content */
main {
    flex: 1;
    overflow-y: auto;
    padding: 15px;
}

.auction-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 15px;
    max-width: 1200px;
    margin: 0 auto;
}

/* Auction Card */
.card {
    background-color: var(--card-background);
    border: 1px solid var(--border-color);
    border-radius: 4px;
    overflow: hidden;
    cursor: pointer;
    transition: transform 0.2s, box-shadow 0.2s;
    display: flex;
    flex-direction: column;
}

.card:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 24px var(--shadow-color);
}

.card-image {
    width: 100%;
    height: 200px;
    object-fit: cover;
    background-color: var(--border-color);
}

.card-content {
    padding: 15px;
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.card-title {
    margin: 0;
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--text-primary);
    /* Truncate text */
    display: -webkit-box;
    -webkit-line-clamp: 2;
    line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.card-meta {
    font-size: 0.9rem;
    color: var(--text-secondary);
}

.card-price {
    font-size: 1.2rem;
    font-weight: 700;
    color: var(--primary-color);
    margin-top: auto;
}

.status-badge {
    display: inline-flex;
    align-items: center;
    padding: 4px 10px;
    border-radius: 16px;
    font-size: 0.8rem;
    font-weight: 500;
    background-color: var(--border-color);
    color: var(--text-secondary);
    margin-right: 5px;
}

.status-urgent {
    background-color: rgba(209, 52, 56, 0.15);
    color: var(--danger-color);
}

[data-theme="dark"] .status-urgent {
    background-color: rgba(255, 107, 107, 0.2);
}

/* Loading & Empty States */
.loader,
.message {
    text-align: center;
    padding: 40px;
    color: var(--text-secondary);
    grid-column: 1 / -1;
}

.hidden {
    display: none !important;
}

/* Statistics Page Styles */
.stats-container {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    height: 80%;
    text-align: center;
}

.construction-icon {
    font-size: 4rem;
    margin-bottom: 20px;
}

/* Grouping Features (Phase 2) */

/* Override grid to allow vertical stacking of groups */
.auction-grid {
    display: block;
    /* Reset previous grid properties if necessary, though block overrides grid display */
}

/* Responsive mini-grid for items inside categories */
.auction-grid-mini {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 15px;
    padding: 10px;
}

/* Group Containers */
details.group-site,
details.group-category {
    margin-bottom: 0.8rem;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    background-color: var(--card-background);
    overflow: hidden;
}

/* Site Level */
details.group-site {
    box-shadow: 0 1px 3px var(--shadow-color);
}

summary.summary-site {
    background-color: var(--background-color);
    padding: 1rem;
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    display: flex;
    gap: 10px;
    align-items: center;
    list-style: none;
}

/* Category Level */
details.group-category {
    margin: 10px;
    border: 1px solid var(--border-color);
}

summary.summary-category {
    padding: 0.8rem;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    background-color: var(--surface-color);
    border-bottom: 1px solid var(--border-color);
    list-style: none;
}

.group-site-content {
    background-color: var(--surface-color);
    padding: 5px 0;
}

/* Custom Expand/Collapse Icons */
summary::-webkit-details-marker {
    display: none;
}

summary::after {
    content: '+';
    font-size: 1.2rem;
    color: var(--primary-color);
}

details[open]>summary::after {
    content: '-';
}

/* Count Badge */
.badge-count {
    background-color: var(--primary-color);
    color: white;
    padding: 2px 8px;
    border-radius: 12px;
    font-size: 0.85rem;
}

.card-location {
    font-size: 0.85rem;
    color: var(--text-secondary);
    margin-top: 4px;
}

/* Header Actions & Theme Toggle */
.header-actions {
    display: flex;
    align-items: center;
    gap: 8px;
}

.icon-btn {
    background: none;
    border: none;
    color: white;
    padding: 8px;
    cursor: pointer;
    border-radius: 4px;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: background-color 0.2s;
}

.icon-btn:hover {
    background-color: rgba(255, 255, 255, 0.1);
}

.icon-btn:focus-visible {
    outline: 2px solid white;
    outline-offset: 2px;
}

/* Theme toggle icon visibility */
.icon-sun { display: none; }
.icon-moon { display: block; }
[data-theme="dark"] .icon-sun { display: block; }
[data-theme="dark"] .icon-moon { display: none; }

/* Vendor Icons */
.vendor-icon {
    width: 22px;
    height: 22px;
    flex-shrink: 0;
    vertical-align: middle;
}

/* SVG vendor icons inherit text color */
svg.vendor-icon {
    fill: currentColor;
}

/* Image vendor icons (ICO/PNG) */
img.vendor-icon {
    object-fit: contain;
    border-radius: 2px;
}

/* Input styling for dark mode */
input,
select {
    background-color: var(--surface-color);
    color: var(--text-primary);
}

input::placeholder {
    color: var(--text-secondary);
}

/* Modern card improvements */
.card {
    border-radius: 8px;
}

.card:focus-visible {
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}

/* Responsive Breakpoints */
@media (max-width: 767px) {
    .filter-row {
        flex-direction: column;
    }

    .filter-row > * {
        flex: none !important;
        width: 100%;
    }

    header {
        padding: 10px 16px;
    }

    header h1 {
        font-size: 1.1rem;
    }

    main {
        padding: 10px;
    }

    .auction-grid-mini {
        grid-template-columns: 1fr;
        gap: 12px;
        padding: 8px;
    }

    .card-image {
        height: 180px;
    }
}

@media (min-width: 768px) {
    .auction-grid-mini {
        grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    }
}

@media (min-width: 1024px) {
    .auction-grid-mini {
        grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
        gap: 20px;
    }
}

/* Accessibility: Reduced Motion */
@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        transition-duration: 0.01ms !important;
        animation-duration: 0.01ms !important;
    }
}

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

:focus:not(:focus-visible) {
    outline: none;
}