:root {
    --primary-color: #007bff;
    --secondary-color: #6c757d;
    --success-color: #28a745;
    --danger-color: #dc3545;
    --warning-color: #ffc107;
    --info-color: #17a2b8;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}

.navbar-brand {
    font-size: 1.5rem;
    letter-spacing: 2px;
}

.card {
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
    transition: box-shadow 0.3s ease;
}

.card:hover {
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.15);
}

.btn {
    border-radius: 6px;
    padding: 0.5rem 1.5rem;
}

.list-group-item {
    border-radius: 6px !important;
    margin-bottom: 0.5rem;
    border: 1px solid #dee2e6;
}

.list-group-item:hover {
    background-color: #f8f9fa;
}

.bg-primary {
    background-color: var(--primary-color) !important;
}

.btn-primary {
    background-color: var(--primary-color);
    border-color: var(--primary-color);
}

.btn-primary:hover {
    background-color: #0056b3;
    border-color: #004085;
}

.text-primary {
    color: var(--primary-color) !important;
}

/* File upload area */
.upload-area {
    border: 2px dashed #dee2e6;
    border-radius: 8px;
    padding: 2rem;
    text-align: center;
    cursor: pointer;
    transition: all 0.3s ease;
}

.upload-area:hover {
    border-color: var(--primary-color);
    background-color: #f8f9fa;
}

.upload-area.dragover {
    border-color: var(--primary-color);
    background-color: #e3f2fd;
}

/* Activity log */
.activity-item {
    padding: 0.75rem;
    border-left: 3px solid var(--primary-color);
    margin-bottom: 0.5rem;
    background-color: #f8f9fa;
}

/* Responsive */
@media (max-width: 768px) {
    .navbar-brand {
        font-size: 1.2rem;
    }
}