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

body{
    background-color: azure;
}

header {
    background-color: #1F150C;
    color: #ffffff;
    padding: 16px;
    text-align: center;
}

nav{
    display: flex;
    justify-content: center;
    background-color: #555555;
    padding: 10px;
}

nav a{
    color: yellow;
    text-decoration: none;
    margin: 0 16px; /*(trên-dưới) (trái phải)*/
}

nav a:hover{
    color: red;
}

ul{
    list-style-type: none;
}

ul li{
    display: inline-block; /*Chung 1 hàng*/
    width: 150px;
    position: relative; 
}

.submenu {
   display: none; /*ẩn đi*/
   position: absolute; /*hiển thị k đẩy các ptu khác giãn ra*/
   background-image: linear-gradient(to right, black, white);
}

.submenu li{
    padding-top: 2px;
    padding-bottom: 2px;
    border: 1px dotted white;
}

.menu li:hover .submenu{
    display: block;
}

.products{
    display: grid;
    grid-template-columns: repeat(4,1fr); /*4 cột, giãn bằng nhau*/
    gap: 20px;
    padding: 30px;
}

.product {
    background-color: white;
    border-radius: 8px;
    padding: 16px;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.1) ; /*lech trai-phai-do day- mau*/
    display: flex;
    flex-direction: column;
    align-items: center;
}

.product img{
    width: 100px;
    height: 100px;
    border-radius: 4px;
}

.product button{
    background-color: #A8DF8E;
    border-radius: 3px;
}