body {
    margin: 0;
    padding: 0;
    font-family: -apple-system, system-ui, Segoe UI, Roboto, Ubuntu, Cantarell, Noto Sans, sans-serif, BlinkMacSystemFont, Helvetica Neue, PingFang SC, Hiragino Sans GB, Microsoft YaHei, Arial;
}

a {
    text-decoration: none;
}

.clearfix::after {
    content: "";
    display: block;
    clear: both;
}

.header.transparent {
    background: transparent;
}

.header.transparent::after {
    content: "";
    width: 100%;
    height: 2px;
    background: linear-gradient(to right, rgba(255, 255, 255, 0), rgba(255, 255, 255, 1), rgba(255, 255, 255, 0));
    position: absolute;
    left: 0px;
    top: 78px;
}

.header.transparent .logo span {
    color: #FFFFFF;
}

.header.transparent .nav .button {
    background: rgba(255, 255, 255, 0.14);
    border: 2px solid #FFFFFF;
    color: #FFFFFF;
    line-height: 31px;
}

.top {
    width: 100%;

    height: 37.5vw;
    min-height: 540px;
    background: url("/images/background.png") no-repeat center;
    background-size: cover;
}

.top-cont {
    padding-top: 80px;
    width: 70%;
    min-width: 750px;
    height: calc(100% - 80px);
    margin: 0 auto;

}

.top-left {
    width: 40%;
    height: 100%;
    float: left;
    position: relative;
}

.top-let-img {
    width: 100%;
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
}

.top-let-img img {
    width: 45%;
    display: block;
    float: left;
}

.top-let-img img:first-child {
    margin-right: 10%;
}

.top-right {
    width: 54%;
    height: 100%;
    float: right;
    position: relative;
}

.top-right-main {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
}

.top-title {
    width: 278px;
    height: 34px;
}

.top-right-main h1 {
    font-size: 36px;
    color: #FFFFFF;
    line-height: 42px;
    margin: 17px 0 45px;
    font-weight: normal;
}

.download-btn {
    display: inline-block;
}

.download-btn a {
    display: inline-block;
    width: 40%;
    max-width: 215px;
}

.download-btn a:first-child {
    margin-right: 30px;
}

.download-btn img {
    width: 100%;
    height: auto;
    display: block;
}

.main {
    width: 100%;
    padding: 92px 0 135px;
    background: #FAFAFA;
    text-align: center;
}

.main h2 {
    font-size: 34px;
    color: #4B4B4B;
    line-height: 39px;
    margin: 0 0 88px 0;
}

.main-cont {
    width: 87%;
    max-width: 1300px;
    min-width: 850px;
    margin: 0 auto;
    display: flex;
    flex-wrap: wrap;
    justify-content: space-between;
}

.main-item {
    width: 31%;
    box-shadow: 0px 2px 11px 0px rgba(31, 13, 42, 0.18);
    border-radius: 40px;
    box-sizing: border-box;
    flex: 1;
    padding: 55px 30px 70px;
    margin-right: 4.5%;
}

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

.item-img {
    margin-bottom: 28px;
}

.item-img img {
    width: 113px;
    height: 113px;
    display: block;
    margin: 0 auto;
}

.item-tit {
    font-size: 24px;
    font-weight: bold;
    color: #4B4B4B;
    line-height: 28px;
    margin-bottom: 16px;
}

.main-item p {
    font-size: 18px;
    color: #4B4B4B;
    line-height: 25px;
    margin: 0;
}


@media screen and (min-width: 1680px) {
    .top-cont {
        width: 60%;
    }
}

@media screen and (max-width: 900px) {
    .top {
        height: auto;
    }

    .top-cont {
        width: 95%;
        min-width: 0;
    }

    .top-left,
    .top-right {
        width: 100%;
        margin-top: 40px;
    }

    .top-let-img,
    .top-right-main {
        position: static;
        top: 0;
        transform: unset;
        text-align: center;
    }

    .top-let-img {
        width: 90%;
        margin: 0 auto;
    }

    .download-btn {
        width: 100%;
        margin-bottom: 40px;
    }

    .main-cont {
        width: 90%;
        min-width: 0;
        display: block;
    }

    .main-item {
        width: 100%;
        margin-right: 0;
        margin-bottom: 30px;
    }

}

@media screen and (max-width: 500px) {
    .download-btn a {
        width: 100%;
        margin-bottom: 20px;
    }

    .download-btn a:first-child {
        margin-right: 0;
    }
}