body { 
    font-family: arial, san-serif;
    margin: 0;
    padding: 0;
}
header {
    background-color: #222;
    color: white;
    padding: 12px;
    text-align: center;
}
.promo {
background-image: url(../images/phonebgrd.jpg);
background-size: 100%;
opacity: 0.5;
height: 300px;
display: flex ;
align-items: center;
justify-content: center;
color: white;
font-size: 4em;
text-shadow: 3px 3px 2pxm black;
color: yellow;
}
.description {
    display: flex;
    flex-wrap: warp;
    gap: 12px;
    padding: 20px;
    justify-content: center;
}
.feature {
    flex: 1 1 200px;/*flex-grow, flex-shrink,flex-basic*/
    border: 1px solid #ccc;
    padding: 12px;
    border-radius: 8px;
}
.action{
    background: #28a745;
    color: white;
    padding: 30px;
    text-align:center;
}
.action button{
    padding: 15px 30px;
    border-radius: 10px;
}
button:hover
{
    background-color: #abe7f5;
}