/* Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #f8f9fa;
}

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

/* Header */
.header {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 1rem 0;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.8rem;
    font-weight: 700;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

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

.nav {
    display: flex;
    gap: 1rem;
}

.nav-link {
    color: white;
    text-decoration: none;
    padding: 0.5rem 1rem;
    border-radius: 5px;
    transition: background-color 0.3s;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.nav-link:hover,
.nav-link.active {
    background-color: rgba(255,255,255,0.2);
}

/* Main Content */
.main {
    min-height: calc(100vh - 140px);
    padding: 2rem 0;
}

.view {
    display: none;
}

.view.active {
    display: block;
}

/* Hero Section */
.hero {
    text-align: center;
    margin-bottom: 3rem;
    padding: 2rem 0;
    background: white;
    border-radius: 10px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}

.hero h2 {
    font-size: 2.5rem;
    color: #2c3e50;
    margin-bottom: 1rem;
}

.hero p {
    font-size: 1.1rem;
    color: #666;
    max-width: 800px;
    margin: 0 auto;
}

/* Controls Section */
.controls {
    background: white;
    padding: 2rem;
    border-radius: 10px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    margin-bottom: 2rem;
}

.filters {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1rem;
    margin-bottom: 2rem;
}

.filter-group {
    display: flex;
    flex-direction: column;
}

.filter-group label {
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: #2c3e50;
}

.filter-select {
    padding: 0.75rem;
    border: 2px solid #e1e8ed;
    border-radius: 5px;
    font-size: 0.9rem;
    transition: border-color 0.3s;
}

.filter-select:focus {
    outline: none;
    border-color: #667eea;
}

.search-sort {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 2rem;
    flex-wrap: wrap;
}

.search-box {
    position: relative;
    flex: 1;
    min-width: 300px;
}

.search-box i {
    position: absolute;
    left: 1rem;
    top: 50%;
    transform: translateY(-50%);
    color: #666;
}

.search-box input {
    width: 100%;
    padding: 0.75rem 1rem 0.75rem 2.5rem;
    border: 2px solid #e1e8ed;
    border-radius: 5px;
    font-size: 1rem;
    transition: border-color 0.3s;
}

.search-box input:focus {
    outline: none;
    border-color: #667eea;
}

.sort-controls {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.sort-controls label {
    font-weight: 600;
    color: #2c3e50;
}

.sort-select {
    padding: 0.75rem;
    border: 2px solid #e1e8ed;
    border-radius: 5px;
    font-size: 0.9rem;
}

.sort-btn {
    padding: 0.75rem;
    border: 2px solid #e1e8ed;
    border-radius: 5px;
    background: white;
    cursor: pointer;
    transition: all 0.3s;
}

.sort-btn:hover {
    background: #f8f9fa;
    border-color: #667eea;
}

/* Results Summary */
.results-summary {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 2rem;
    padding: 1rem;
    background: white;
    border-radius: 5px;
    box-shadow: 0 1px 5px rgba(0,0,0,0.1);
}

.results-summary p {
    font-weight: 600;
    color: #2c3e50;
}

/* Buttons */
.btn {
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: 5px;
    font-size: 0.9rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    text-decoration: none;
}

.btn-primary {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 15px rgba(102, 126, 234, 0.4);
}

.btn-secondary {
    background: #6c757d;
    color: white;
}

.btn-secondary:hover {
    background: #5a6268;
    transform: translateY(-2px);
}

.btn-outline {
    background: transparent;
    border: 2px solid #667eea;
    color: #667eea;
}

.btn-outline:hover {
    background: #667eea;
    color: white;
}

/* Dataset Grid */
.dataset-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
    gap: 2rem;
}

.dataset-card {
    background: white;
    border-radius: 10px;
    padding: 1.5rem;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    transition: all 0.3s;
    cursor: pointer;
    border: 2px solid transparent;
}

.dataset-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 25px rgba(0,0,0,0.15);
    border-color: #667eea;
}

.dataset-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: 1rem;
}

.dataset-code {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: 600;
}

.dataset-meta-header {
    display: flex;
    gap: 0.5rem;
    align-items: center;
}

.dataset-language {
    background: #f3e5f5;
    color: #4a148c;
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: 600;
    display: inline-flex;
    align-items: center;
    gap: 0.25rem;
}

.dataset-language i {
    font-size: 0.7rem;
    opacity: 0.8;
}

.dataset-year {
    background: #d1ecf1;
    color: #0c5460;
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: 600;
}

.dataset-size {
    background: #e9ecef;
    color: #495057;
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: 600;
}

.dataset-title {
    font-size: 1.2rem;
    font-weight: 700;
    color: #2c3e50;
    margin-bottom: 0.5rem;
    line-height: 1.3;
}

.dataset-description {
    color: #666;
    font-size: 0.9rem;
    line-height: 1.5;
    margin-bottom: 1rem;
    display: -webkit-box;
    -webkit-line-clamp: 3;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

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

.meta-tag {
    background: #f8f9fa;
    color: #495057;
    padding: 0.25rem 0.5rem;
    border-radius: 15px;
    font-size: 0.75rem;
    font-weight: 500;
}

.meta-tag {
    display: inline-flex;
    align-items: center;
    gap: 0.25rem;
}

.meta-tag i {
    font-size: 0.7rem;
    opacity: 0.8;
}

.meta-tag.license {
    background: #d4edda;
    color: #155724;
}

.meta-tag.domain {
    background: #cce5ff;
    color: #004085;
}

.meta-tag.task {
    background: #fff3cd;
    color: #856404;
}

.meta-tag.artifact {
    background: #f8d7da;
    color: #721c24;
}

.meta-tag.granularity {
    background: #d1ecf1;
    color: #0c5460;
}

.meta-tag.stage {
    background: #e2e3e5;
    color: #383d41;
}

.meta-tag.language {
    background: #f3e5f5;
    color: #4a148c;
}

.dataset-labels {
    margin-top: 1rem;
}

.labels-title {
    font-size: 0.8rem;
    font-weight: 600;
    color: #666;
    margin-bottom: 0.5rem;
}

.label-group {
    display: flex;
    flex-wrap: wrap;
    gap: 0.25rem;
}

.label {
    background: #e3f2fd;
    color: #1976d2;
    padding: 0.2rem 0.5rem;
    border-radius: 10px;
    font-size: 0.7rem;
    font-weight: 500;
}

/* Detail View */
.detail-header {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 2rem;
}

.detail-header h2 {
    color: #2c3e50;
    font-size: 2rem;
}

.detail-content {
    background: white;
    border-radius: 10px;
    padding: 2rem;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}

.detail-section {
    margin-bottom: 2rem;
}

.detail-section h3 {
    color: #2c3e50;
    font-size: 1.3rem;
    margin-bottom: 1rem;
    padding-bottom: 0.5rem;
    border-bottom: 2px solid #e1e8ed;
}

.detail-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1rem;
}

.detail-item {
    display: flex;
    flex-direction: column;
}

.detail-label {
    font-weight: 600;
    color: #666;
    font-size: 0.9rem;
    margin-bottom: 0.25rem;
}

.detail-value {
    color: #2c3e50;
    font-size: 1rem;
}

.detail-value a {
    color: #667eea;
    text-decoration: none;
}

.detail-value a:hover {
    text-decoration: underline;
}

.detail-description {
    background: #f8f9fa;
    padding: 1.5rem;
    border-radius: 5px;
    border-left: 4px solid #667eea;
    margin: 1rem 0;
}

.publications-list {
    list-style: none;
}

.publications-list li {
    background: #f8f9fa;
    padding: 1rem;
    border-radius: 5px;
    margin-bottom: 1rem;
    border-left: 4px solid #28a745;
}

.publication-title {
    font-weight: 600;
    color: #2c3e50;
    margin-bottom: 0.5rem;
}

.publication-authors {
    color: #666;
    font-size: 0.9rem;
    margin-bottom: 0.5rem;
}

.publication-meta {
    display: flex;
    gap: 1rem;
    font-size: 0.8rem;
    color: #666;
}

.extends-link {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    color: #667eea;
    text-decoration: none;
    font-weight: 600;
    padding: 0.5rem 1rem;
    border: 2px solid #667eea;
    border-radius: 5px;
    transition: all 0.3s;
}

.extends-link:hover {
    background: #667eea;
    color: white;
}

/* Footer */
.footer {
    background: #2c3e50;
    color: white;
    text-align: center;
    padding: 2rem 0;
    margin-top: 3rem;
}

/* Loading States */
.loading {
    text-align: center;
    padding: 3rem;
    color: #666;
}

.loading i {
    font-size: 2rem;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    from { transform: rotate(0deg); }
    to { transform: rotate(360deg); }
}

/* Responsive Design */
@media (max-width: 768px) {
    .header .container {
        flex-direction: column;
        gap: 1rem;
    }
    
    .nav {
        width: 100%;
        justify-content: center;
    }
    
    .hero h2 {
        font-size: 2rem;
    }
    
    .filters {
        grid-template-columns: 1fr;
    }
    
    .search-sort {
        flex-direction: column;
        align-items: stretch;
    }
    
    .search-box {
        min-width: auto;
    }
    
    .sort-controls {
        justify-content: space-between;
    }
    
    .dataset-grid {
        grid-template-columns: 1fr;
    }
    
    .detail-grid {
        grid-template-columns: 1fr;
    }
    
    .results-summary {
        flex-direction: column;
        gap: 1rem;
        text-align: center;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 15px;
    }
    
    .hero {
        padding: 1.5rem 1rem;
    }
    
    .controls {
        padding: 1.5rem;
    }
    
    .detail-content {
        padding: 1.5rem;
    }
}