body {
    background-color: #f0f2f6;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

.main-header {
    background: linear-gradient(90deg, #1e3c72 0%, #2a5298 100%);
    padding: 1.5rem;
    border-radius: 10px;
    color: white;
    margin-bottom: 2rem;
    margin-top: 1rem;
}

.main-header h1 {
    margin: 0;
    font-size: 1.8rem;
}

.main-header p {
    margin: 0.5rem 0 0 0;
    opacity: 0.9;
}

.sidebar {
    background-color: white;
    padding: 1.5rem;
    border-radius: 10px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    margin-bottom: 1rem;
}

.sidebar h3, .sidebar h5 {
    color: #1e3c72;
    margin-bottom: 1rem;
}

.upload-section, .active-file, .filters-section {
    margin-bottom: 2rem;
    padding-bottom: 1rem;
    border-bottom: 1px solid #e0e0e0;
}

.metric-card {
    background-color: white;
    padding: 1rem;
    border-radius: 10px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    text-align: center;
    margin-bottom: 1rem;
}

.metric-card h3 {
    margin: 0;
    color: #1e3c72;
    font-size: 1.8rem;
    font-weight: bold;
}

.metric-card p {
    margin: 0.5rem 0 0 0;
    color: #666;
}

.nav-tabs {
    background-color: white;
    padding: 0.5rem;
    border-radius: 10px;
    margin-bottom: 1rem;
}

.nav-tabs .nav-link {
    color: #1e3c72;
    border: none;
    padding: 0.5rem 1rem;
}

.nav-tabs .nav-link.active {
    background-color: #1e3c72;
    color: white;
    border-radius: 5px;
}

.tab-content {
    background-color: white;
    padding: 1.5rem;
    border-radius: 10px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.table-responsive {
    margin-top: 1rem;
}

.table th {
    background-color: #1e3c72;
    color: white;
    border: none;
}

.btn-primary {
    background-color: #1e3c72;
    border-color: #1e3c72;
}

.btn-primary:hover {
    background-color: #2a5298;
    border-color: #2a5298;
}

.alert-info {
    background-color: #e8f4f8;
    border-color: #b8e0f0;
    color: #1e3c72;
}