body {
    margin: 0;
    font-family: Arial, sans-serif;
    background: #f8f8f8;
}
header {
    background: #333;
    color: white;
    text-align: center;
    padding: 10px 0;
}
header h1 {
    margin: 0;
    font-size: 28px;
}
header p {
    margin: 5px 0 0;
    font-size: 14px;
}
nav {
    background: #444;
    display: flex;
    justify-content: center;
}
nav ul {
    list-style: none;
    margin: 0;
    padding: 0;
    display: flex;
}
nav ul li {
    position: relative;
}
nav ul li a {
    display: block;
    padding: 12px 20px;
    color: white;
    text-decoration: none;
}
nav ul li a:hover {
    background: #ffcc00;
    color: black;
}

/* Menu con (dropdown) */
nav ul li ul {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    background: #555;
    min-width: 160px;
    z-index: 1000;
}
nav ul li ul li {
    width: 100%;
}
nav ul li ul li a {
    padding: 10px;
    color: white;
}
nav ul li ul li a:hover {
    background: #ffcc00;
    color: red;
}
nav ul li:hover ul {
    display: block;
}

/* Lưới sản phẩm */
.products {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: 20px;
    padding: 20px;
    max-width: 1000px;
    margin: auto;
}
.product {
    background: white;
    border: 1px solid #ddd;
    border-radius: 6px;
    text-align: center;
    padding: 15px;
}
.product img {
    width: 100%;
    height: 150px;
    object-fit: contain;
    margin-bottom: 10px;
}
.product h3 {
    font-size: 16px;
    margin: 10px 0 5px;
}
.product p {
    margin: 5px 0;
    color: gray;
    font-weight: bold;
}
.product button {
    margin-top: 10px;
    padding: 8px 15px;
    border: none;
    background: #28a745;
    color: white;
    border-radius: 4px;
    cursor: pointer;
}
.product button:hover {
    background: #218838;
}