:root {
    --primary-color: #2c3e50;
    --secondary-color: #34495e;
    --accent-color: #3498db;
    --success-color: #27ae60;
    --danger-color: #e74c3c;
    --light-bg: #f8f9fa;
    --text-color: #2c3e50;
    --border-color: #dee2e6;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    margin: 0;
    padding: 0;
    background-color: var(--light-bg);
    color: var(--text-color);
}

.navbar {
    background-color: var(--primary-color);
    padding: 1rem 2rem;
    color: white;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.navbar-brand {
    font-size: 1.5rem;
    font-weight: bold;
    text-decoration: none;
    color: white;
}

.navbar-nav {
    display: flex;
    gap: 1.5rem;
}

.nav-link {
    color: #ecf0f1;
    text-decoration: none;
    transition: color 0.3s;
}

.nav-link:hover {
    color: var(--accent-color);
}

.container {
    max-width: 1200px;
    margin: 2rem auto;
    padding: 0 1rem;
}

.card {
    background: white;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.05);
    padding: 1.5rem;
    margin-bottom: 1.5rem;
}

.card-header {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 1rem;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 0.5rem;
}

.grid-3 {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 1.5rem;
}

.stat-box {
    padding: 1.5rem;
    border-radius: 8px;
    color: white;
    text-align: center;
}

.bg-primary { background-color: var(--accent-color); }
.bg-success { background-color: var(--success-color); }
.bg-danger { background-color: var(--danger-color); }
.bg-info { background-color: #17a2b8; }
.bg-warning { background-color: #f39c12; }

.stat-value {
    font-size: 2rem;
    font-weight: bold;
    margin: 0.5rem 0;
}

.stat-label {
    font-size: 0.9rem;
    opacity: 0.9;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.table {
    width: 100%;
    border-collapse: collapse;
    margin-bottom: 1rem;
}

.table th, .table td {
    padding: 0.75rem;
    border-bottom: 1px solid var(--border-color);
    text-align: left;
}

.table th {
    background-color: #f8f9fa;
    font-weight: 600;
}

.form-group {
    margin-bottom: 1rem;
}

.form-label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
}

.form-control {
    width: 100%;
    padding: 0.5rem;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    font-size: 1rem;
}

.btn {
    display: inline-block;
    padding: 0.5rem 1rem;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    font-size: 1rem;
    text-decoration: none;
    transition: background-color 0.3s;
}

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

.btn-danger {
    background-color: var(--danger-color);
    color: white;
}

.btn:hover {
    opacity: 0.9;
}

.filter-bar {
    background: white;
    padding: 1rem;
    border-radius: 8px;
    display: flex;
    gap: 1rem;
    align-items: end;
    margin-bottom: 2rem;
    box-shadow: 0 2px 4px rgba(0,0,0,0.05);
}