.columns {
    width: 100%;
}

.columns img {
    width: 100%;
}

.columns__container {
    width: 100%;
    max-width: 750px;
    margin: 0 auto;
    padding: 70px 0 10px;
}

.columns__ttl {
    margin: 0 0 30px 0;
    padding: 0;
    line-height: 0;
}

.columns__items {
    width: 100%;
    display: flex;
    flex-wrap: wrap;
    margin-bottom: 30px;
}

.columns__item {
    width: calc((100% - 30px) / 2);
    margin-right: 30px;
    margin-bottom: 30px;
}

.columns__item a {
    transition: opacity .5s ease-out;
}

.columns__item a:hover {
    opacity: .7;
}

.columns__item:nth-of-type(2n) {
    margin-right: 0;
}

@media only screen and (max-width: 640px) {
    .columns {
        width: 90%;
        margin: 0 auto;
    }

    .columns__container {
        padding: 8vw 0 1vw;
    }

    .columns__ttl {
        margin: 0 0 4vw 0;
    }

    .columns__ttl {
        margin: 0 0 4vw 0;
    }

    .columns__items {
        margin-bottom: 4vw;
    }

    .columns__item {
        width: calc((100% - 4vw) / 2);
        margin-right: 4vw;
        margin-bottom: 4vw;
    }

    .columns__item:nth-of-type(2n) {
        margin-right: 0;
    }
}