* {
    margin: 0;
    padding: 0;
}
.nav {
    width: calc(100% - 80px);
    height: 90px;
    line-height: 90px;
    position: fixed;
    top: 0;
    left: 0;
    background: #fff;
    z-index: 99;
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin: 0 40px;
    box-sizing: border-box;
}
.nav_list {
    display: flex;
    justify-content: center;

}
.item {
    margin-left: 40px;
    color: #333;
}
.item:hover {
    color: #37c3e3;
}
a {
    text-decoration: none; 
    color: #333;
}
a:hover {
    color: #37c3e3;
}
.active {
    color: #37c3e3;
}
.logo {
    width: 230px;
    height: 52px;
}