.banner {
    position: relative;
    height: 400px;
    overflow: hidden;
}

.ban-back {
    position: absolute;
    z-index: 1;
    overflow: hidden;
    left: 0;
    bottom: 0;
    right: 0;
}

.ban-color {
    width: 100%;
    height: 100%;
    z-index: 2;
    background-color: rgba(128, 128, 128, 0.274);
    position: absolute;
    top: 0;
    left: 0;
    bottom: 0;
    right: 0;
}

.ban-text {
    width: 40%;
    position: absolute;
    padding: 1% 3%;
    margin: 0 auto;
    height: 100%;
    display: flex;
    flex-direction: column;
    justify-content: space-evenly;
    z-index: 3;
    font-size: 20px;
    color: #fff;
}

.ban-top {
    width: 76%;
    font-size: 48px;
}

.ban-back img {
    height: 100%;
}

@media (max-width:999px) {
    .ban-back {
        top: -10%;
    }

    .ban-back img {
        height: 100%;
    }

    .ban-text {
        width: 100%;
    }

    .ban-top {
        width: 101%;
    }
}