/* 头部样式 */
.header {
    background: var(--white);
    box-shadow: 0 .125rem .625rem rgba(0, 0, 0, 0.1);
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
}

.nav-wrapper {
    display: flex;
    align-items: center;
    padding: 1rem 0;
    height: 5rem;
}

.logo-placeholder {
    width: 5.6875rem;
    height: 2.1875rem;
    background-image: url(../images/pc/header-logo.png);
    background-size: 100% 100%;
    background-repeat: no-repeat;
}

.nav-menu {
    margin-left: 16.125rem;
    margin-right: auto;
}

.nav-menu ul {
    display: flex;
    list-style: none;
    gap: 2rem;
}

.nav-menu a {
    color: var(--text-dark);
    font-weight: 500;
}


.nav-menu li:nth-child(1)>a:hover {
    color: #785598;
}

.nav-menu li:nth-child(2)>a:hover {
    color: #5CC1C5;
}

.nav-menu li:nth-child(3)>a:hover {
    color: #DD4646;
}

.nav-menu li:nth-child(4)>a:hover {
    color: #F5CC2A;
}

/* 针对激活项的颜色 */
.nav-menu li:nth-child(1).active>a {
    color: #785598;
}

.nav-menu li:nth-child(2).active>a {
    color: #5CC1C5;
}

.nav-menu li:nth-child(3).active>a {
    color: #DD4646;
}

.nav-menu li:nth-child(4).active>a {
    color: #F5CC2A;
}

.nav-right {
    display: flex;
    align-items: center;
}

.nav-right img {
    width: 2.25rem;
    height: 1.5rem;
}

.nav-right a {
    font-family: Noto Sans;
    font-size: .875rem;
    line-height: 1.125rem;
    letter-spacing: .1rem;
    text-align: center;
    color: #3D354F;
}

.mobile-menu-toggle {
    display: none;
    background-image: url(../images/mobile/header-menu.png);
    background-size: 100% 100%;
    background-repeat: no-repeat;
    width: 3.75rem;
    height: 3.75rem;
    margin-left: auto;
}

.mobile-menu-toggle.active {
    background-image: url(../images/mobile/header-close.png);
}

/* 下拉菜单基础样式 */
.nav-menu li {
    position: relative;
}

.nav-menu-dropdown {
    position: absolute;
    top: 100%;
    left: 0;
    background: var(--white);
    box-shadow: 0 .125rem .625rem rgba(0, 0, 0, .1);
    padding: .5rem 0;
    display: none;
    flex-direction: column;
    min-width: 8rem;
    gap: .5rem;
    z-index: 100;
}

.nav-menu-dropdown a {
    white-space: nowrap;
    color: var(--text-dark);
    font-size: .875rem;
    padding: .5rem 1rem;
}

/* 下拉菜单 hover 颜色 */
.nav-menu li:nth-child(2) .nav-menu-dropdown a:hover {
    color: #fff;
    background-color: #5CC1C5;
}

.nav-menu li:nth-child(3) .nav-menu-dropdown a:hover {
    color: #fff;
    background-color: #DD4646;
}

/* 悬浮时显示下拉菜单 */
.nav-menu li:hover>.nav-menu-dropdown {
    display: flex;
}

/* ================== 移动端侧边导航样式 ================== */
.mobile-nav {
    position: fixed;
    top: 3.75rem;
    left: 0;
    width: 100%;
    height: calc(100vh - 3.75rem);
    background: #fff;
    box-shadow: .125rem 0 .5rem rgba(0, 0, 0, .1);
    transform: translateX(-100%);
    transition: transform .3s ease;
    z-index: 1200;
    overflow-y: auto;
    box-sizing: border-box;
    padding: 3rem 2.6875rem;
}

.mobile-nav.active {
    transform: translateX(0);
}

.mobile-nav-list {
    width: 100%;
    list-style: none;
    padding: 0 1.25rem;
    margin: 0;
    display: flex;
    flex-direction: column;
    gap: 4rem;
}

.mobile-nav-list>li>a,
.mobile-nav-list>li>span {
    font-weight: 700;
    font-size: 1.5rem;
    letter-spacing: .1rem;
    color: #3D354F;
}

.mobile-nav-list>li.active:nth-child(1)>a,
.mobile-nav-list>li.active:nth-child(1)>span {
    color: #785598;
}

.mobile-nav-list>li.active:nth-child(2)>a,
.mobile-nav-list>li.active:nth-child(2)>span {
    color: #5CC1C5;
}

.mobile-nav-list>li.active:nth-child(3)>a,
.mobile-nav-list>li.active:nth-child(3)>span {
    color: #DD4646;
}

.mobile-nav-list>li.active:nth-child(4)>a,
.mobile-nav-list>li.active:nth-child(4)>span {
    color: #F5CC2A;
}

/* 子菜单 */
.sub-menu {
    list-style: none;
    margin: .75rem 0 0 .75rem;
    padding: 0;
    display: flex;
    flex-direction: column;
    gap: 2rem;
}

.sub-menu li a {
    font-weight: 500;
    font-size: 1.125rem;
    letter-spacing: .1rem;

    color: #3D354F;
    display: flex;
    align-items: center;
}

/* 彩色小圆点 */
.bullet {
    display: inline-block;
    width: .625rem;
    height: .625rem;
    border-radius: 50%;
    margin-right: .5rem;
}

.bullet.teal {
    background: #5CC1C5;
}

.bullet.red {
    background: #DD4646;
}

.heder-img1 {
    width: 5.1875rem;
    height: 7.625rem;
    position: absolute;
    top: 17.8125rem;
    right: 0;
}

.heder-img2 {
    width: 8.5rem;
    height: 8.5625rem;
    position: absolute;
    top: 24.5625rem;
    right: 1.5625rem;
}

.heder-img3 {
    width: 9.4375rem;
    height: 13.125rem;
    position: absolute;
    top: 32rem;
    right: 0;
}

/* 响应式：移动端显示汉堡按钮，隐藏PC菜单 */
@media (max-width: 48rem) {

    .nav-menu,
    .nav-right {
        display: none;
    }

    .mobile-menu-toggle {
        display: block;
    }

    .nav-wrapper {
        box-sizing: border-box;
        height: 3.75rem;
        width: 100%;
        padding: 0 .9375rem;
    }

    .logo-placeholder {
        width: 4.875rem;
        height: 1.875rem;
        background-image: url(../images/mobile/header-logo.png);
    }
}