header {
    height: 90px;
    width: 100%;
}

header .container {
    display: flex;
    justify-content: space-between;
}

/* logo */
header .logo {
    width: 300px;
    height: 90px;
    display: flex;
    align-items: center;
}

header .logo img {
    width: 100%;
    height: auto;
}

/* 导航 */
header .nav {
    width: 850px;
    box-sizing: border-box;
    display: flex;
    justify-content: flex-start;
    align-items: center;
    border-bottom: 1px solid #a8a8a8;
    font-size: 16px;
}

.nav .level1 {
    flex: 1;
    text-align: center;
    position: relative;
    height: 90px;
    display: flex;
    justify-content: center;
    align-items: center;
}

.nav .level1 a {
    display: block;
    color: black;

}

.nav .level1 .remark {
    font-size: 12px;
    color: #817f7f;
    text-transform: uppercase;
}

.nav .level1:first-child a {
    border-left: 0;
}

.nav .level1 a:hover {
    color: #ff7920;
}

.nav .level1 ul {
    position: absolute;
    top: 90.5px;
    width: 100%;
    z-index: 90;
    height: 0;
    border-radius: 3px;
    overflow: hidden;
}

.nav .level1:nth-child(2):hover ul {
    transition: 1s;
    min-height: 300px;
}

.nav .level1:nth-child(4):hover ul {
    transition: 1s;
    min-height: 300px;
}

.nav .level1:nth-child(7):hover ul {
    transition: 1s;
    min-height: 300px
}

.nav .level1 ul li {
    width: 100%;
    border-right: 0;
    background: #F3F3F3;
    z-index: 900;
}

.nav .level1 ul li a {
    font-size: 12px;
    line-height: 40px;
    border-top: 1px solid #a8a8a8;
}

.nav .level1 ul li:first-child a {
    border-top: none;
}

.nav .level1:hover {
    color: #1F1715;
}

.nav .line {
    height: 50px;
    border-left: 1px solid #a8a8a8;
    position: absolute;
    left: 0px;
    top: 20px;
}