:root {
    --primary-color: #ff6b35;
    --secondary-color: #004e89;
    --bg-color: #f8f9fa;
    --card-bg: #ffffff;
    --text-color: #333;
    --border-color: #e0e0e0;
    --hover-color: #f0f0f0;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--bg-color);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Header */
header {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    padding: 2rem 0;
    text-align: center;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

header h1 {
    font-size: 2.5rem;
    margin-bottom: 0.5rem;
}

.subtitle {
    font-size: 1.1rem;
    opacity: 0.9;
    margin-bottom: 0.5rem;
}

.subtitle-small {
    font-size: 0.9rem;
    opacity: 0.85;
}

/* Stats Section */
.stats-section {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1.5rem;
    margin: 2rem 0;
}

.stat-card {
    background: var(--card-bg);
    padding: 1.5rem;
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
    text-align: center;
    transition: transform 0.2s;
}

.stat-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 4px 12px rgba(0,0,0,0.15);
}

.stat-card h3 {
    font-size: 2rem;
    color: var(--primary-color);
    margin-bottom: 0.5rem;
}

.stat-card p {
    color: #666;
    font-size: 0.9rem;
}

/* Search Section */
.search-section {
    background: var(--card-bg);
    padding: 1.5rem;
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
    margin-bottom: 2rem;
}

.search-container {
    margin-bottom: 1rem;
}

#search-input {
    width: 100%;
    padding: 0.75rem;
    font-size: 1rem;
    border: 2px solid var(--border-color);
    border-radius: 4px;
    transition: border-color 0.2s;
}

#search-input:focus {
    outline: none;
    border-color: var(--primary-color);
}

.filters {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1rem;
}

.filters select {
    padding: 0.75rem;
    font-size: 1rem;
    border: 2px solid var(--border-color);
    border-radius: 4px;
    background: white;
    cursor: pointer;
    transition: border-color 0.2s;
}

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

/* Datasets Grid */
.datasets-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.dataset-card {
    background: var(--card-bg);
    border-radius: 8px;
    padding: 1.5rem;
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
    transition: transform 0.2s, box-shadow 0.2s;
    cursor: pointer;
}

.dataset-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 4px 16px rgba(0,0,0,0.15);
}

.dataset-header {
    margin-bottom: 1rem;
}

.dataset-title {
    font-size: 1.2rem;
    font-weight: 600;
    color: var(--secondary-color);
    margin-bottom: 0.5rem;
    word-break: break-word;
}

.dataset-author {
    color: #666;
    font-size: 0.9rem;
}

.dataset-description {
    font-size: 0.9rem;
    color: #555;
    margin-bottom: 1rem;
    line-height: 1.5;
    display: -webkit-box;
    -webkit-line-clamp: 3;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.dataset-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-bottom: 1rem;
}

.tag {
    background: var(--bg-color);
    padding: 0.25rem 0.75rem;
    border-radius: 12px;
    font-size: 0.75rem;
    color: #555;
}

.tag.language {
    background: #e3f2fd;
    color: #1976d2;
}

.tag.task {
    background: #f3e5f5;
    color: #7b1fa2;
}

.dataset-stats {
    display: flex;
    justify-content: space-between;
    font-size: 0.85rem;
    color: #666;
    padding-top: 1rem;
    border-top: 1px solid var(--border-color);
}

.stat-item {
    display: flex;
    align-items: center;
    gap: 0.25rem;
}

/* Loading & No Results */
.loading, .no-results {
    text-align: center;
    padding: 3rem;
    color: #666;
    font-size: 1.1rem;
}

/* Pagination */
.pagination {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 1rem;
    margin: 2rem 0;
}

.pagination button {
    padding: 0.75rem 1.5rem;
    font-size: 1rem;
    border: 2px solid var(--primary-color);
    background: white;
    color: var(--primary-color);
    border-radius: 4px;
    cursor: pointer;
    transition: all 0.2s;
}

.pagination button:hover:not(:disabled) {
    background: var(--primary-color);
    color: white;
}

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

#page-info {
    font-weight: 600;
}

/* Footer */
footer {
    background: var(--card-bg);
    padding: 2rem 0;
    text-align: center;
    margin-top: 3rem;
    border-top: 1px solid var(--border-color);
}

footer p {
    margin: 0.5rem 0;
    color: #666;
}

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

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

/* Responsive */
@media (max-width: 768px) {
    header h1 {
        font-size: 1.8rem;
    }

    .datasets-grid {
        grid-template-columns: 1fr;
    }

    .filters {
        grid-template-columns: 1fr;
    }
}