body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: #f4f4f4;
    margin: 0;
    padding: 0;
    color: #333;
}

header {
    background-color: #2c3e50;
    color: white;
    padding: 1rem 0;
}

.container {
    width: 90%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
}

nav ul {
    list-style: none;
    padding: 0;
    margin: 0;
    text-align: center;
}

nav ul li {
    display: inline;
    margin: 0 15px;
}

nav ul li a {
    color: white;
    text-decoration: none;
    font-weight: bold;
    font-size: 1.1em;
}

nav ul li a:hover {
    text-decoration: underline;
}

h1, h2, h3 {
    color: #2c3e50;
}

.card-container {
    display: flex;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 20px;
    margin-bottom: 20px;
}

.card {
    background: white;
    padding: 20px;
    border-radius: 8px;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
    flex: 1;
    min-width: 200px;
    text-align: center;
}

.card h3 {
    margin-top: 0;
    color: #7f8c8d;
    font-size: 1em;
}

.card .value {
    font-size: 2em;
    font-weight: bold;
    color: #27ae60;
}

table {
    width: 100%;
    border-collapse: collapse;
    background: white;
    border-radius: 8px;
    overflow: hidden;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
    margin-bottom: 20px;
}

table th, table td {
    padding: 12px 15px;
    text-align: left;
    border-bottom: 1px solid #ddd;
}

table th {
    background-color: #34495e;
    color: white;
}

table tr:hover {
    background-color: #f1f1f1;
}

.btn {
    display: inline-block;
    padding: 10px 15px;
    background-color: #3498db;
    color: white;
    text-decoration: none;
    border-radius: 4px;
    border: none;
    cursor: pointer;
    font-size: 1em;
}

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

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

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

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

.btn-success:hover {
    background-color: #219150;
}

form {
    background: white;
    padding: 20px;
    border-radius: 8px;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
    max-width: 600px;
    margin: 0 auto;
}

form label {
    display: block;
    margin-bottom: 5px;
    font-weight: bold;
}

form input, form textarea, form select {
    width: 100%;
    padding: 10px;
    margin-bottom: 15px;
    border: 1px solid #ddd;
    border-radius: 4px;
    box-sizing: border-box;
}

.pos-container {
    display: flex;
    gap: 20px;
}

.pos-products {
    flex: 2;
}

.pos-cart {
    flex: 1;
    background: white;
    padding: 20px;
    border-radius: 8px;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
    height: fit-content;
}

.cart-total {
    font-size: 1.5em;
    font-weight: bold;
    text-align: right;
    margin-top: 15px;
    border-top: 2px solid #ddd;
    padding-top: 10px;
}

.alert {
    padding: 10px;
    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;
}