.ban-ban {
    background-size: cover;
    height: 100vh;
    width: 100%;
    display: flex;
    justify-content: center;
    align-items: center;
}

.group {
    position: absolute;
    text-align: center;
    white-space: nowrap;
    overflow: hidden;
}
.item {
    width: 15vw;
    height: 75vh;
    background-position: center;
    background-size: 75vh;
    margin: 1vw;
    border-radius: 3vw;
    display: inline-block;
    cursor: pointer;
    background-size: cover;
    z-index: 3;
}
.flex-slider{
    display: flex;
    flex-flow: row nowrap;
    overflow: hidden;
    height: 80vh;
    width: 100%;

}

.flex-slider-item-img{
    width: 100%;
    height: auto;
}
.active:hover{
    flex-basis: 50%;
}
.flex-slider-item{
    display: flex;
    justify-content: center;
    align-items: center;
    align-content: center;
    background:linear-gradient(to right, rgba(0, 0, 0,0.4), rgba(0, 0, 0,0.3)),
    url('https://upload.wikimedia.org/wikipedia/ru/thumb/9/94/%D0%93%D0%B8%D0%B3%D0%B0%D1%87%D0%B0%D0%B4.jpg/640px-%D0%93%D0%B8%D0%B3%D0%B0%D1%87%D0%B0%D0%B4.jpg');
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    flex-basis: 25%;
    transition: 1000ms ease-in-out;
}
.flex-slider-item-text{
    margin-left: 5%;
    margin-right: 5%;
}
.flex-slider-item-text{
    font-weight: 100;
    font-size: 24px;
    transition: 350ms ease-in-out;
}
.active:hover .flex-slider-item-text{
    font-size: 2.4vw;

}
.flex-slider-item-text{
    color: #fff;
}