body{
    margin: 0;
    font-family: Arial, Helvetica, sans-serif;
}



header{
    text-align: center;
    background-color: black;
    color: white;
    padding: 12px ;
    text-shadow: 3px 3px 2px lightgray;
}

.banner{
    background-image: url(../images/phonebgrd.jpg);
    background-size: 100%;
    height: 250px;
    display: flex;
    align-items: center;/*căn lề theo chiều dọc*/
    justify-content: center;/*căn lề theo chiều ngang*/
    color: rgb(193, 73, 18);
    opacity: 50%;
    text-shadow: 3px 3px 2px lightgray;
}

.container{
    display: flex;
    flex-wrap: wrap;
    gap: 15px;
    padding: 20px;
    justify-content: center;
}   

.card{
    flex: 1 1 200px;/*flex-grow, flex-shrink,flex-basic*/;
    border: 1px solid lightgrey;
    border-radius: 5px;
    padding: 15px;
}

.content{
    font-weight: bold;
} 

p{
    font-style: italic;
}

footer{
    text-align: center;
    background-color: green;
    color: white;
    padding: 12px ;
}

button{
    padding: 15px 30px;
    border: 1px solid lightgray;
    border-radius: 5px;
}

button:hover{
    transform: scale(1.05);
    transition: transform 0.3s;
}