body{
    font-family: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
    margin :0;
    padding: 0;
}
header{
    background-color: black;
    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: aliceblue;
    font-size: 4em;
    text-shadow: 5 5 10px black;
    color:  rgb(0, 238, 255);
    

}
.promo:hover{
    opacity: 1;
    transition: 1s ease;
}
.promo:not(:hover){
    opacity: 0.5;
    transition: 1s ease;
}
.description{
    display: flex;
    flex-wrap: wrap;
    gap : 12px;
    padding: 20px;
    justify-content: center;

}

.feature{
    flex : 1 1 200px;
    border: 1px solid whitesmoke;
    padding: 12px;
    border-radius: 8px;
}
.feature:hover{
    transform: scale(1.05);
    transition: 1s ease;
    box-shadow: 0 0 10px gray;
}

.feature:not(:hover){
    transform: scale(1);
    transition: 1s ease;
    box-shadow: 0 0 10px rgb(255, 255, 255);
}
.action{
    border: 1px solid;
    border-radius: 10px;
    background: greenyellow;
    color: darkgreen;
    padding: 30px;
    text-align: center;
}
.action button{
    padding: 15px 30px;
    border-radius: 10px;
}
.action button:hover{
    transform: scale(1.2);
    transition: 0.5s ease-out;
}
.action button:not(:hover){
    transform: scale(1);
    transition: 0.5s ease;
}
.action:hover{
    transform: rotate(-5deg);
    transition: 1s ease;
}
.action:not(:hover){
    transform: rotate(0deg);
    transition: 1s ease;
}