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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: #f5f5f5;
    color: #333;
    line-height: 1.6;
}

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

header {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 30px;
    border-radius: 10px;
    margin-bottom: 30px;
    text-align: center;
    box-shadow: 0 4px 15px rgba(0,0,0,0.1);
}

header h1 {
    font-size: 2.5em;
    font-weight: 300;
}

.main-content {
    display: grid;
    gap: 30px;
}

.add-product-section {
    background: white;
    padding: 25px;
    border-radius: 10px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}

.add-product-section h2 {
    color: #667eea;
    margin-bottom: 20px;
    font-size: 1.5em;
}

.form-group {
    margin-bottom: 20px;
}

.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
    margin-bottom: 20px;
}

.form-buttons {
    display: flex;
    gap: 15px;
    margin-top: 20px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 600;
    color: #555;
}

.form-group input {
    width: 100%;
    padding: 12px;
    border: 2px solid #e1e1e1;
    border-radius: 5px;
    font-size: 16px;
    transition: border-color 0.3s ease;
}

.form-group input:focus {
    outline: none;
    border-color: #667eea;
}

button {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border: none;
    padding: 12px 25px;
    border-radius: 5px;
    font-size: 16px;
    cursor: pointer;
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

button:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 15px rgba(102, 126, 234, 0.4);
}

button:active {
    transform: translateY(0);
}

.products-section {
    background: white;
    padding: 25px;
    border-radius: 10px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}

.products-section h2 {
    color: #667eea;
    margin-bottom: 20px;
    font-size: 1.5em;
}

.table-container {
    overflow-x: auto;
}

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

th, td {
    padding: 15px;
    text-align: left;
    border-bottom: 1px solid #e1e1e1;
}

th {
    background-color: #f8f9fa;
    font-weight: 600;
    color: #555;
    position: sticky;
    top: 0;
}

tr:hover {
    background-color: #f8f9fa;
}

.status-badge {
    padding: 5px 10px;
    border-radius: 20px;
    font-size: 12px;
    font-weight: 600;
    text-transform: uppercase;
}

.status-pending {
    background-color: #ffeaa7;
    color: #d63031;
}

.status-invoiced {
    background-color: #55efc4;
    color: #00b894;
}

.action-btn {
    background: linear-gradient(135deg, #00b894 0%, #00cec9 100%);
    margin-right: 10px;
    margin-bottom: 10px;
}

.action-btn:hover {
    box-shadow: 0 4px 15px rgba(0, 184, 148, 0.4);
}

.edit-btn {
    background: linear-gradient(135deg, #fdcb6e 0%, #e17055 100%);
    padding: 8px 15px;
    font-size: 14px;
    margin-right: 5px;
}

.edit-btn:hover {
    box-shadow: 0 4px 15px rgba(253, 203, 110, 0.4);
}

.delete-btn {
    background: linear-gradient(135deg, #e17055 0%, #d63031 100%);
    padding: 8px 15px;
    font-size: 14px;
}

.delete-btn:hover {
    box-shadow: 0 4px 15px rgba(225, 112, 85, 0.4);
}

.actions-section {
    text-align: center;
    padding: 20px;
}

/* Modal Styles */
.modal {
    display: none;
    position: fixed;
    z-index: 1000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0,0,0,0.5);
}

.modal-content {
    background-color: white;
    margin: 15% auto;
    padding: 30px;
    border-radius: 10px;
    width: 90%;
    max-width: 500px;
    position: relative;
    box-shadow: 0 4px 20px rgba(0,0,0,0.3);
}

.close {
    color: #aaa;
    float: right;
    font-size: 28px;
    font-weight: bold;
    cursor: pointer;
    position: absolute;
    right: 20px;
    top: 15px;
}

.close:hover {
    color: #000;
}

.modal-content h2 {
    color: #667eea;
    margin-bottom: 20px;
}

/* Responsive Design */
@media (max-width: 768px) {
    .container {
        padding: 10px;
    }
    
    header h1 {
        font-size: 2em;
    }
    
    .main-content {
        gap: 20px;
    }
    
    .add-product-section,
    .products-section {
        padding: 20px;
    }
    
    .form-row {
        grid-template-columns: 1fr;
        gap: 15px;
    }
    
    .form-buttons {
        flex-direction: column;
    }
    
    table {
        font-size: 12px;
    }
    
    th, td {
        padding: 8px 4px;
    }
    
    .action-btn {
        width: 100%;
        margin-bottom: 10px;
    }
    
    .edit-btn, .delete-btn {
        width: 100%;
        margin-bottom: 5px;
        margin-right: 0;
    }
}

@media (max-width: 480px) {
    table {
        font-size: 11px;
    }
    
    th, td {
        padding: 6px 2px;
    }
    
    .status-badge {
        font-size: 10px;
        padding: 3px 6px;
    }
}

/* Loading Animation */
.loading {
    display: inline-block;
    width: 20px;
    height: 20px;
    border: 3px solid #f3f3f3;
    border-top: 3px solid #667eea;
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

/* Success/Error Messages */
.message {
    padding: 15px;
    margin: 20px 0;
    border-radius: 5px;
    font-weight: 600;
}

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

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