SOURCE

<div class="container">
    <div class="big">
        <div class="small">1</div>
    </div>
    <div class="big">
        <div class="small">2</div>
    </div>
    <div class="big">
        <div class="small">3</div>
    </div>
</div>

.container {
    display: flex;
}
.small {
    width: 70px;
    height: 100px;
    background: white;
    border-radius: 12px;
    display: flex;
    justify-content: center;
    align-items: center;
}
.big {
    padding: 0 10px;
    cursor: pointer;
}

.big:hover .small {
    background: royalblue;
}