*{
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}
html {
    scroll-behavior: smooth;
}
body{
    background: #fff;
    font-size: 14px;
}
header{
    display: flex;
    justify-content: space-between;
    background: #4053F0;
    padding: 0 20px;
}
header .menu{
    width: 20%;
    display: flex;
}
header .menu a{
    display: block;
    text-decoration: none;
    height: 60px;
    line-height: 60px;
    padding: 0 20px;
    color: #fff;
    margin-right: 20px;
    border-bottom: 2px solid transparent;
}
header .menu a:hover{
    border-bottom: 2px solid #fff;
}
#home{
    width: 100%;
    height: 650px;
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 48px;
    font-weight: bold;
    background: url("../image/home.jpg") no-repeat;
    background-size: 100% 100%;
    flex-direction: column;
    color: #fff;
}
#home .content{
    width: 80%;
}
#about_us{
    padding: 40px 0;
}
#about_us .content{
    width: 60%;
    margin: 0 auto;
}
#about_us .us_tl{
    font-weight: bold;
    text-align: center;
    font-size: 24px;
}
#about_us img {
    width: 100%;
    margin-top: 20px;
}
footer{
    background: #3B3B40;
    color: #efefef;
}
footer .content{
    width: 50%;
    margin: 0 auto;
}
footer .con_top{
    display: flex;
    padding: 30px 0;
    border-bottom: 1px solid #999;
}
footer .con_card{
    width: 23%;
    border-right: 1px solid #999;
    margin-right: 20px;
}
footer .con_card:last-child{
    border-right: none;
}
footer .foot_tl{
    font-size: 16px;
    margin-bottom: 20px;
}
footer .foot_list .item{
    margin-bottom: 10px;
    font-size: 12px;
}
footer .con_bot{
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 20px;
}
footer .bot_item{
    cursor: pointer;
    margin-right: 20px;
}
footer .bot_item:last-child{
    margin-right: 0;
}
#go_top{
    position: fixed;
    right: 20px;
    bottom: 20px;
    background: #232324;
    border-radius: 5px;
    cursor: pointer;
    width: 40px;
    height: 40px;
    display: none;
}
#go_top img{
    display: block;
    vertical-align: middle;
    margin: 8px auto 0;
}