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

body {
    font-family: Arial, sans-serif;
    background-color: #f4f4f4;
    padding: 20px;
}

.container {
    max-width: 1400px;
    margin: 0 auto;
    background-color: white;
    padding: 20px;
    border-radius: 8px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}

h1, h2 {
    color: #333;
    margin-bottom: 20px;
}

.header {
    background-color: #2c3e50;
    color: white;
    padding: 20px;
    margin: -20px -20px 20px -20px;
    border-radius: 8px 8px 0 0;
}

.header h1 {
    color: white;
    margin: 0;
}

.nav {
    background-color: #34495e;
    padding: 10px;
    margin: -20px -20px 20px -20px;
}

.nav a {
    color: white;
    text-decoration: none;
    padding: 10px 20px;
    display: inline-block;
    margin-right: 5px;
    border-radius: 4px;
    transition: background-color 0.3s;
}

.nav a:hover, .nav a.active {
    background-color: #2c3e50;
}

.btn {
    padding: 10px 20px;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    font-size: 14px;
    transition: background-color 0.3s;
}

.btn-primary {
    background-color: #3498db;
    color: white;
}

.btn-primary:hover {
    background-color: #2980b9;
}

.btn-success {
    background-color: #27ae60;
    color: white;
}

.btn-success:hover {
    background-color: #229954;
}

.btn-danger {
    background-color: #e74c3c;
    color: white;
}

.btn-danger:hover {
    background-color: #c0392b;
}

.btn-warning {
    background-color: #f39c12;
    color: white;
}

.btn-warning:hover {
    background-color: #d68910;
}

.form-group {
    margin-bottom: 15px;
}

.form-group label {
    display: block;
    margin-bottom: 5px;
    font-weight: bold;
    color: #555;
}

.form-group input,
.form-group select,
.form-group textarea {
    width: 100%;
    padding: 10px;
    border: 1px solid #ddd;
    border-radius: 4px;
    font-size: 14px;
}

.form-group input:focus,
.form-group select:focus {
    outline: none;
    border-color: #3498db;
}

.form-row {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 15px;
}

table {
    width: 100%;
    border-collapse: collapse;
    margin-top: 20px;
}

table th {
    background-color: #34495e;
    color: white;
    padding: 12px;
    text-align: left;
}

table td {
    padding: 10px;
    border-bottom: 1px solid #ddd;
}

table tr:hover {
    background-color: #f5f5f5;
}

.alert {
    padding: 15px;
    margin-bottom: 20px;
    border-radius: 4px;
}

.alert-success {
    background-color: #d4edda;
    color: #155724;
    border: 1px solid #c3e6cb;
}

.alert-error {
    background-color: #f8d7da;
    color: #721c24;
    border: 1px solid #f5c6cb;
}

.alert-info {
    background-color: #d1ecf1;
    color: #0c5460;
    border: 1px solid #bee5eb;
}

.card {
    background-color: white;
    border-radius: 8px;
    padding: 20px;
    margin-bottom: 20px;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 20px;
    margin-bottom: 30px;
}

.stat-card {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 20px;
    border-radius: 8px;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
}

.stat-card h3 {
    font-size: 14px;
    margin-bottom: 10px;
    opacity: 0.9;
}

.stat-card .stat-value {
    font-size: 32px;
    font-weight: bold;
}

.invoice {
    border: 2px solid #333;
    padding: 30px;
    max-width: 800px;
    margin: 20px auto;
    background-color: white;
}

.invoice-header {
    text-align: center;
    margin-bottom: 30px;
    border-bottom: 2px solid #333;
    padding-bottom: 20px;
}

.invoice-details {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
    margin-bottom: 30px;
}

@media print {
    body {
        padding: 0;
    }
    .container {
        box-shadow: none;
    }
    .nav, .btn {
        display: none;
    }
}

.search-box {
    padding: 10px;
    border: 1px solid #ddd;
    border-radius: 4px;
    width: 300px;
    margin-bottom: 20px;
}

.text-right {
    text-align: right;
}

.text-center {
    text-align: center;
}

.mt-20 {
    margin-top: 20px;
}

.mb-20 {
    margin-bottom: 20px;
}