body {
    font-family: Arial, sans-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;
    color: white;
    font-size: 4em;
    text-shadow: 3px 3px 2px black;
    color: yellow;
    text-align: center;
}

.description {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    padding: 20px;
    justify-content: center;
}

.feature {
    flex: 1 1 200px; /* flex-grow, flex-shrink, flex-basis*/
    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;
}

h1 {
    font-size: 2.5em;
    text-shadow: 5px 5px 3px gray;
}