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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    padding: 20px;
}

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

header {
    text-align: center;
    margin-bottom: 30px;
    color: white;
}

header h1 {
    font-size: 2.5rem;
    margin-bottom: 10px;
}

header p {
    font-size: 1.1rem;
    opacity: 0.9;
}

.drop-zone {
    background: white;
    border: 3px dashed #667eea;
    border-radius: 15px;
    padding: 40px;
    text-align: center;
    margin-bottom: 30px;
    transition: all 0.3s ease;
    cursor: pointer;
}

.drop-zone:hover,
.drop-zone.drag-over {
    border-color: #764ba2;
    background: #f8f9ff;
    transform: translateY(-2px);
}

.drop-zone-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 15px;
}

.drop-icon {
    font-size: 3rem;
}

.drop-zone p {
    font-size: 1.1rem;
    color: #666;
}

.or {
    color: #999;
    font-size: 0.9rem;
}

.select-files-btn {
    background: #667eea;
    color: white;
    border: none;
    padding: 12px 24px;
    border-radius: 8px;
    font-size: 1rem;
    cursor: pointer;
    transition: background 0.3s ease;
}

.select-files-btn:hover {
    background: #764ba2;
}

.controls {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
    flex-wrap: wrap;
    gap: 20px;
}

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

.sort-controls {
    display: flex;
    align-items: center;
    gap: 10px;
    background: white;
    padding: 8px 16px;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.sort-controls label {
    font-weight: 500;
    color: #666;
    font-size: 0.9rem;
}

#sortSelect {
    background: white;
    border: 1px solid #ddd;
    border-radius: 6px;
    padding: 5px 10px;
    font-size: 0.9rem;
    cursor: pointer;
    min-width: 120px;
}

.data-controls {
    display: flex;
    gap: 10px;
    align-items: center;
}

.data-btn {
    background: #667eea;
    color: white;
    border: none;
    border-radius: 6px;
    padding: 8px 12px;
    font-size: 0.9rem;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    gap: 5px;
}

.data-btn:hover {
    background: #5a67d8;
    transform: translateY(-1px);
}

.filter-btn {
    background: white;
    border: 2px solid #667eea;
    color: #667eea;
    padding: 8px 16px;
    border-radius: 20px;
    cursor: pointer;
    transition: all 0.3s ease;
    font-size: 0.9rem;
}

.filter-btn:hover,
.filter-btn.active {
    background: #667eea;
    color: white;
}

.expertise-list {
    display: grid;
    gap: 20px;
}

.expertise-card {
    background: white;
    border-radius: 12px;
    padding: 20px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    transition: all 0.3s ease;
}

.expertise-card:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 12px rgba(0, 0, 0, 0.15);
}

.expertise-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: 15px;
}

.header-controls {
    display: flex;
    align-items: center;
    gap: 10px;
}

.expertise-title {
    font-size: 1.2rem;
    font-weight: 600;
    color: #333;
    flex: 1;
}

.status-select {
    background: #f0f0f0;
    border: 1px solid #ddd;
    border-radius: 6px;
    padding: 5px 10px;
    font-size: 0.9rem;
    cursor: pointer;
}

.delete-btn {
    background: #ff4757;
    color: white;
    border: none;
    border-radius: 6px;
    padding: 5px 8px;
    font-size: 0.9rem;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    justify-content: center;
    min-width: 32px;
    height: 32px;
}

.delete-btn:hover {
    background: #ff3742;
    transform: scale(1.05);
}

.expertise-details {
    display: grid;
    gap: 10px;
}

.detail-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.detail-label {
    font-weight: 500;
    color: #666;
}

.detail-value {
    color: #333;
}

.due-date {
    font-weight: 600;
}

.due-date.urgent {
    color: #e74c3c;
}

.due-date.warning {
    color: #f39c12;
}

.due-date.normal {
    color: #27ae60;
}

.progress-indicator {
    height: 4px;
    background: #f0f0f0;
    border-radius: 2px;
    margin-top: 15px;
    overflow: hidden;
}

.progress-bar {
    height: 100%;
    background: linear-gradient(90deg, #667eea, #764ba2);
    border-radius: 2px;
    transition: width 0.3s ease;
}

.empty-state {
    text-align: center;
    padding: 60px 20px;
    color: white;
    opacity: 0.8;
}

.empty-state h3 {
    font-size: 1.5rem;
    margin-bottom: 10px;
}

@media (max-width: 768px) {
    .container {
        padding: 10px;
    }
    
    header h1 {
        font-size: 2rem;
    }
    
    .drop-zone {
        padding: 30px 20px;
    }
    
    .controls {
        flex-direction: column;
        align-items: stretch;
    }
    
    .filters {
        justify-content: center;
    }
    
    .sort-controls {
        justify-content: center;
    }
    
    .data-controls {
        justify-content: center;
        margin-top: 10px;
    }
    
    .expertise-header {
        flex-direction: column;
        gap: 10px;
        align-items: stretch;
    }
    
    .header-controls {
        justify-content: space-between;
    }
}