.example {
    position: relative;
    height: 100%;
    margin: 0;
    padding: 0;
}

.swiper-slide {
    text-align: center;
    font-size: 18px;
    background: #fff;
}

.swiper-container {
    height: 426px;
    width: 640px;

}

.swiper-lazy {
    height: 426px;
    background: #eee no-repeat center 0;
    background-size: auto 100%;
}

.swiper-lazy img {
    height: inherit;
    width: auto;
}


@media (max-width: 638px) {

    .swiper-container {
        height: 213px;
        width: 320px;

    }

    .swiper-lazy {
        height: 213px;
        width: 320px;
    }

}