.content-about {
    width: 900px;
    height: auto;
    color: #6e6e6e;
    font-size: 14px;
    line-height: 32px;
    text-align: justify;
    text-indent: 2em;
    position: relative;
    margin: 0 auto;
    overflow: hidden;
}
.about-list {
    width: 900px;
    height: auto;
    display: flex;
    flex-wrap: wrap;
    justify-content: space-between;
    position: relative;
    margin: 22px auto 0;
    overflow: hidden;
}
.about-list li {
    width: 430px;
    height: 344px;
    margin-top: 28px;
    position: relative;
}
.about-list li img {
    display: block;
    margin: 0 auto 18px;
}
.about-txt {
    width: 100%;
    height: 24px;
    color: #4c4c4c;
    font-size: 14px;
    line-height: 24px;
    text-align: center;
    margin: 0 auto;
}
/*************/
.content-certificate {
    width: 900px;
    height: auto;
    display: flex;
    flex-wrap: wrap;
    justify-content: flex-start;
    position: relative;
    margin: 0 auto;
    overflow: hidden;
}
.content-certificate li {
    width: 270px;
    height: 242px;
    margin: 0 45px 30px 0;
    position: relative;
}
.content-certificate li:nth-child(3n) {
    margin-right: 0;
}
.content-certificate li img {
    display: block;
    margin: 0 auto 18px;
}
.certificate-txt {
    width: 100%;
    height: 24px;
    color: #4c4c4c;
    font-size: 14px;
    line-height: 24px;
    text-align: center;
    margin: 0 auto;
}