/* Существующие стили */
body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
    background-color: #f4f4f4;
}

header {
    background-color: #333;
    color: white;
    text-align: center;
    padding: 1rem 0;
}

main {
    display: flex;
    justify-content: space-around;
    padding: 2rem;
}

.products, .add-product {
    background-color: white;
    padding: 2rem;
    border-radius: 5px;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
    width: 45%;
}

.product-list {
    display: flex;
    flex-direction: column;
}

.product-item {
    background-color: #f9f9f9;
    padding: 1rem;
    margin-bottom: 1rem;
    border: 1px solid #ddd;
    border-radius: 5px;
}

form {
    display: flex;
    flex-direction: column;
}

label {
    margin-bottom: 0.5rem;
}

input {
    padding: 0.5rem;
    margin-bottom: 1rem;
    border: 1px solid #ddd;
    border-radius: 5px;
}

button {
    padding: 0.75rem;
    border: none;
    border-radius: 5px;
    background-color: #333;
    color: white;
    cursor: pointer;
    transition: background-color 0.3s;
}

button:hover {
    background-color: #555;
}

/* Новые стили для валидации */
input.valid {
    border-color: green;
}

input.invalid {
    border-color: red;
}