.main-content {
    display: flex;
    flex-direction: column;
    align-items: center;
}


.pic.a7 {
    width: 100%;
    background-repeat: no-repeat;
    height: 168px;
    background-position:center;
    background-size: auto 100%;
    background-color: #01605c;

}

.pic img {
    width: 100vw;
}

.pic-group {
    display: flex;
    flex-direction: row;
    flex-wrap: wrap;
    padding: 6vw 3vw;

}

.pic-group a {
    color: #303030;
    text-decoration: none;
}


.pic-group .item {
    width: 29.3vw;
    margin-right: 3vw;
    text-align: center;
    line-height: 1.4;
}


.pic-group.big .item {
    width: 380px;
    margin-right: 30px;
    margin-bottom: 30px;
}

.pic-group .item img{
    width: 100%;
}
.pic-group.big .item img{
    width: 100%;
}

.pic-group.big .item:nth-child(3n) {
    margin-right: 0;
}

.pic-group .item:last-child {
    margin-right: 0;
}


.tab {
    padding: 3vw 0;
    /*height: 160px;*/
    color: #434343;
    width: 100vw;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
}

.tab .title {
    font-size: 4.5vw;
    font-weight: bold;
    letter-spacing: 6px;
    line-height: 1.5;
}

.tab .sub-title {
    font-size: 3.5vw;
}