/* -------------------------------------------------------------------
 * Header - 顶部导航
 * 桌面端：玻璃效果 + 横向菜单
 * 移动端：独立结构（Uiverse 风格），不受桌面样式约束
------------------------------------------------------------------- */

/* ---------- 共用 ---------- */
.header {
    padding: 10px 0;
    z-index: 3333;
}

/* ---------- 桌面端：仅 ≥992px 显示 ---------- */
.header-desktop {
    display: none;
}

@media screen and (min-width: 992px) {
    .header-desktop {
        display: block;
    }
}

.header-glass-wrap {
    padding: 0;
    overflow: visible;
}

.header-glass-wrap.black-navbar {
    background: transparent !important;
    backdrop-filter: none !important;
    -webkit-backdrop-filter: none !important;
    border-bottom: none !important;
    box-shadow: none !important;
}

.header-glass-wrap .header-glass-inner {
    min-height: 72px;
    border-radius: 0 !important;
    border-bottom: 1px solid rgba(255, 255, 255, 0.12);
    overflow: visible !important;
}

.header-glass-wrap .header-glass-inner.glass-surface--svg,
.header-glass-wrap .header-glass-inner.glass-surface--fallback {
    background: transparent !important;
}

.header-glass-wrap.header-shrink .header-glass-inner::before {
    content: '';
    position: absolute;
    inset: 0;
    border-radius: inherit;
    background: rgba(80, 80, 90, 0.35);
    pointer-events: none;
    z-index: 0;
}

.header-glass-wrap.header-shrink .header-glass-inner .glass-surface__content {
    z-index: 1;
}

.header-glass-wrap .header-glass-inner .glass-surface__content {
    padding: 0;
    min-height: 72px;
    display: block;
    overflow: visible;
}

.header-glass-wrap.header-shrink .header-glass-inner {
    border-bottom-color: rgba(255, 255, 255, 0.08);
}

.header .header-desktop .dropdown-menu {
    z-index: 9999;
}

.header .header-desktop .container {
    display: flex;
    align-items: center;
    max-width: 100%;
    width: 100%;
    padding-left: 80px;
    padding-right: 80px;
}

.header .header-desktop .navbar {
    width: 100%;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.header .header-desktop .navbar .navbar-collapse {
    flex: 1;
    display: flex;
    justify-content: flex-end;
}

.header .header-desktop ul li {
    list-style-type: none;
}

.header .header-desktop .nav-link {
    font-size: 16px;
    font-weight: 400;
    padding: 20px 25px !important;
    text-transform: uppercase;
    letter-spacing: 0.6px;
    display: block;
    position: relative;
    color: #fff;
    line-height: 28px;
    /* 防止浏览器变窄时导航文字在链接内部换行 */
    white-space: nowrap;
    word-break: keep-all;
    box-sizing: border-box;
}

/* 进一步防止导航折行（在 ≥992px 的桌面端生效） */
.header .header-desktop .navbar,
.header .header-desktop .navbar-collapse,
.header .header-desktop .navbar-nav {
    flex-wrap: nowrap;
}

/* 宽度变窄时适当缩小导航间距，避免文字仍需换行 */
@media screen and (max-width: 1180px) and (min-width: 992px) {
    .header .header-desktop .nav-link {
        font-size: 14px;
        padding: 20px 14px !important;
        letter-spacing: 0.3px;
    }
}

.header .header-desktop .nav-link.active::after {
    content: '';
    position: absolute;
    left: 0;
    right: 0;
    bottom: 0;
    width: 100%;
    height: 7px;
    background-color: #23c87a;
    box-sizing: border-box;
}

.header .header-desktop .nav-link:not(.active)::after {
    content: '';
    position: absolute;
    left: 0;
    bottom: 0;
    width: 100%;
    height: 7px;
    z-index: -7;
    transition: transform 0.4s ease;
    background-color: #23c87a;
    transform: scaleX(0);
    transform-origin: 100% 0;
}

.header .header-desktop .nav-link:not(.active):hover::after {
    transform: scaleX(1);
    transform-origin: 0 0;
}

.header .header-desktop .nav-item.dropdown {
    position: relative;
}

.header .header-desktop .dropdown-menu {
    border: 0;
    background: #fff;
    padding: 0;
    margin: 0;
    border-radius: 8px;
    overflow: hidden;
    left: 0;
    min-width: 100%;
    width: 100%;
    box-sizing: border-box;
    box-shadow: 0px 13px 35px 0 rgba(43, 50, 54, 0.2);
}

.header .header-desktop .dropdown-menu .dropdown-item {
    display: block;
    width: 100%;
    padding: 14px 28px;
    font-weight: 400;
    color: rgb(0, 0, 0);
    text-decoration: none;
    position: relative;
    text-align: center;
    transition: all 0.25s ease;
}

.header .header-desktop .dropdown-menu .dropdown-item:hover {
    color: #fff;
    background-color: #23c87a;
    padding-left: 25px;
}

.header .header-desktop .dropdown-toggle {
    position: relative;
    padding-right: 25px !important;
    text-align: center;
}

.header .header-desktop .dropdown-toggle:before {
    content: "\f078";
    position: absolute;
    top: 50%;
    right: 0;
    font-weight: 700;
    font-size: 12px;
    font-family: "Font Awesome 5 Free";
    transition: all 0.25s ease;
    transform: translateY(-50%);
}

.header .header-desktop .dropdown-toggle[aria-expanded="true"]:before {
    transform: rotate(180deg);
    top: 20px;
}

.header .header-desktop .navbar-brand {
    color: #fff;
    margin-right: 0;
    padding: 0;
    height: 56px;
    display: flex;
    align-items: center;
}

.header .header-desktop .navbar-brand img {
    height: 50%;
    width: auto;
    max-height: 28px;
    object-fit: contain;
}

.header .header-desktop .navbar-brand img.logo-transparent {
    display: block;
}

.header .header-desktop .navbar-brand img.logo-normal {
    display: none;
}

.header.header-shrink .header-desktop .navbar-brand img.logo-transparent {
    display: none !important;
}

.header.header-shrink .header-desktop .navbar-brand img.logo-normal {
    display: block !important;
}

.header.header-shrink {
    padding: 0;
    background: rgba(0, 0, 0, 0.45);
    backdrop-filter: blur(11px) saturate(1);
    -webkit-backdrop-filter: blur(11px) saturate(1);
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
    box-shadow: 0 0 2px 1px rgba(255, 255, 255, 0.05) inset, 0px 13px 35px -12px rgba(43, 50, 54, 0.25);
    animation: stickyMenu 0.7s ease-in-out;
}

.header.header-shrink .header-desktop .nav-link {
    position: relative;
    color: rgb(255, 255, 255) !important;
}

.header.header-shrink .header-desktop .navbar-brand {
    color: #23c87a;
}

@media screen and (min-width: 992px) {
    .header .header-desktop .dropdown-menu {
        position: absolute;
        top: 80%;
        left: 0;
        opacity: 0;
        visibility: hidden;
        display: initial;
        min-width: 100%;
        width: 100%;
        color: #000;
        border: 0;
        border-radius: 8px;
        transition: all 0.5s ease;
    }

    .header .header-desktop .dropdown-menu.show {
        opacity: 1;
        top: 100%;
        visibility: visible;
    }
}

@keyframes stickyMenu {
    0% {
        margin-top: -120px;
        opacity: 0;
    }

    50% {
        margin-top: -64px;
        opacity: 0;
    }

    100% {
        margin-top: 0;
        opacity: 1;
    }
}

#login-form {
    z-index: 6666;
}

#signup-form {
    z-index: 7777;
}

/* -------------------------------------------------------------------
 * 移动端导航：仅 <992px 显示，完全独立（参考 Uiverse by pathikcomp）
 * 不使用 .navbar / .nav-link 等，避免被桌面全局样式约束
------------------------------------------------------------------- */
.header-mobile {
    display: none;
}

@media screen and (max-width: 991.98px) {
    .header-desktop {
        display: none !important;
    }

    .header-mobile {
        display: block;
        position: relative;
    }

    /* 小屏下整块 header 深色背景（移动端不套 GlassSurface） */
    .header.header-glass-wrap {
        background: #0c0e14 !important;
        backdrop-filter: none !important;
        -webkit-backdrop-filter: none !important;
        padding: 0;
        border-bottom: 1px solid rgba(255, 255, 255, 0.06);
    }

    .header-mobile .mobile-nav-bar {
        font-weight: 800;
        color: white;
        background-color: #0c0e14;
        padding: 10px 16px;
        border-radius: 10px;
        display: flex;
        align-items: center;
        height: 3.5rem;
        width: 100%;
        position: relative;
        justify-content: space-between;
        box-sizing: border-box;
    }

    .mobile-nav-logo {
        display: flex;
        align-items: center;
        color: inherit;
        text-decoration: none;
    }

    .mobile-nav-logo img {
        height: 28px;
        width: auto;
        max-height: 28px;
        object-fit: contain;
    }

    .mobile-nav-trigger {
        -webkit-appearance: none;
        appearance: none;
        display: flex;
        align-items: center;
        gap: 10px;
        height: 100%;
        padding: 0;
        border: none;
        background: transparent;
        color: white;
        border-radius: 10px;
        padding: 0 14px;
        cursor: pointer;
        font: inherit;
        font-weight: 800;
        transition: background 0.3s;
    }

    .mobile-nav-trigger:hover {
        background: transparent;
    }

    .mobile-nav-trigger-text {
        font-size: 14px;
    }

    .mobile-nav-center-title {
        position: absolute;
        left: 50%;
        top: 50%;
        transform: translate(-50%, -50%);
        max-width: 55%;
        font-size: 12px;
        line-height: 1.2;
        color: #ffffff;
        text-align: center;
        white-space: nowrap;
        overflow: hidden;
        text-overflow: ellipsis;
        pointer-events: none;
    }

    /* 学习页手机端：左侧主菜单替 Logo */
    .mobile-nav-logo-btn {
        display: flex;
        align-items: center;
        gap: 8px;
        background: transparent;
        border: none;
        padding: 0;
        cursor: pointer;
        color: inherit;
        text-decoration: none;
    }

    .mobile-study-menu-icon {
        display: inline-flex;
        align-items: center;
        justify-content: center;
        width: 28px;
        height: 28px;
        border-radius: 8px;
        background: rgba(255, 255, 255, 0.08);
        border: 1px solid rgba(255, 255, 255, 0.12);
        font-size: 18px;
        line-height: 1;
    }

    .mobile-study-menu-text {
        font-size: 14px;
        font-weight: 800;
        letter-spacing: 0.02em;
    }

    /* 学习页手机端：右侧「课程选择」 */
    .mobile-course-trigger {
        padding: 0 10px;
        gap: 8px;
    }

    .mobile-course-chevron {
        width: 0;
        height: 0;
        border-left: 6px solid transparent;
        border-right: 6px solid transparent;
        border-top: 7px solid rgba(255, 255, 255, 0.9);
        transform: rotate(0deg);
        transition: transform 0.2s ease;
    }

    .mobile-course-chevron.is-open {
        transform: rotate(180deg);
    }

    .mobile-course-dropdown {
        position: absolute;
        left: 0;
        top: calc(100% + 6px);
        width: 100%;
        background-color: rgba(12, 14, 20, 0.98);
        border: 1px solid rgba(130, 170, 255, 0.25);
        border-radius: 10px;
        box-shadow: 0 10px 40px rgba(0, 0, 0, 0.4);
        overflow: hidden;
        z-index: 101;
        max-height: 75vh;
        overflow-y: auto;
        display: none;
    }

    .mobile-course-dropdown.is-open {
        display: block;
    }

    .mobile-course-list {
        padding: 8px 0;
    }

    .mobile-course-cat-block {
        border-bottom: 1px solid rgba(255, 255, 255, 0.08);
    }

    .mobile-course-cat-block:last-child {
        border-bottom: 0;
    }

    .mobile-course-cat-btn {
        display: flex;
        align-items: center;
        justify-content: space-between;
        width: 100%;
        padding: 12px 20px;
        font-size: 15px;
        font-weight: 600;
        color: rgba(255, 255, 255, 0.95);
        text-align: left;
        border: none;
        background: transparent;
        cursor: pointer;
        -webkit-appearance: none;
        appearance: none;
        transition: background 0.2s, color 0.2s;
    }

    .mobile-course-cat-btn:hover {
        background: rgba(130, 170, 255, 0.08);
        color: #82aaff;
    }

    .mobile-course-cat-btn.is-open {
        background: rgba(130, 170, 255, 0.12);
        color: #82aaff;
    }

    .mobile-course-products {
        display: grid;
        grid-template-columns: repeat(3, minmax(0, 1fr));
        gap: 10px;
        padding: 10px 16px 16px;
        background: rgba(0, 0, 0, 0.2);
        box-sizing: border-box;
    }

    .mobile-course-product-link {
        display: flex;
        flex-direction: column;
        align-items: center;
        justify-content: flex-start;
        text-decoration: none;
        background: rgba(255, 255, 255, 0.03);
        border-radius: 8px;
        border: 1px solid rgba(255, 255, 255, 0.3);
        padding: 6px 4px 8px;
        box-sizing: border-box;
        color: rgba(255, 255, 255, 0.9);
        transition: background 0.2s, border-color 0.2s, transform 0.15s;
    }

    .mobile-course-product-link:hover {
        background: rgba(130, 170, 255, 0.16);
        border-color: rgba(255, 255, 255, 0.3);
        transform: translateY(-1px);
    }

    .mobile-course-product-thumb {
        width: 100%;
        padding-bottom: 100%;
        position: relative;
        margin-bottom: 4px;
        overflow: hidden;
        border-radius: 6px;
        background: rgba(0, 0, 0, 0.4);

    }

    .mobile-course-product-thumb img {
        position: absolute;
        inset: 0;
        width: 100%;
        height: 100%;
        object-fit: contain;
        display: block;
    }

    .mobile-course-product-title {
        display: block;
        width: 100%;
        font-size: 12px;
        line-height: 1.3;
        text-align: center;
        white-space: nowrap;
        overflow: hidden;
        text-overflow: ellipsis;
    }

    .mobile-course-empty {
        padding: 12px 16px;
        color: rgba(255, 255, 255, 0.55);
        font-size: 13px;
    }

    .mobile-course-products .mobile-course-empty {
        width: 100%;
        padding: 8px 0 0;
    }

    /* 学习详情页手机端：内容导航列表（纯文字按钮） */
    .mobile-content-nav-list {
        padding: 8px 0;
    }

    .mobile-content-nav-item {
        display: block;
        width: 100%;
        padding: 10px 20px;
        font-size: 14px;
        color: rgba(255, 255, 255, 0.9);
        text-align: left;
        text-decoration: none;
        background: transparent;
        border: none;
        border-bottom: 1px solid rgba(255, 255, 255, 0.08);
        cursor: pointer;
        box-sizing: border-box;
    }

    .mobile-content-nav-item:last-child {
        border-bottom: none;
    }

    .mobile-content-nav-item:hover {
        background: rgba(130, 170, 255, 0.12);
        color: #ffffff;
    }

    .mobile-nav-bar-icon {
        display: flex;
        height: 50%;
        width: 20px;
        flex-direction: column;
        gap: 3px;
        justify-content: center;
    }

    .mobile-nav-bar-icon span {
        display: block;
        width: 100%;
        height: 3px;
        border-radius: 50px;
        background-color: white;
        transition: all 0.4s;
        position: relative;
    }

    /* 关闭时三条线，打开时变为 X（参考 .inp:not(:checked) ~ .bar） */
    .mobile-nav-bar-icon:not(.is-open) .top,
    .mobile-nav-bar-icon:not(.is-open) .bottom,
    .mobile-nav-bar-icon:not(.is-open) .middle {
        transform: none;
        opacity: 1;
    }

    .mobile-nav-bar-icon.is-open .top {
        transform-origin: top right;
        transform: translateY(-25%) rotate(-45deg);
    }

    .mobile-nav-bar-icon.is-open .middle {
        transform: translateX(-50%);
        opacity: 0;
    }

    .mobile-nav-bar-icon.is-open .bottom {
        transform-origin: bottom right;
        transform: translateY(25%) rotate(45deg);
    }

    /* 菜单容器：绝对定位，clip-path 展开/收起（参考 .menu-container） */
    .mobile-nav-dropdown {
        background-color: rgba(12, 14, 20, 0.98);
        color: white;
        border-radius: 10px;
        position: absolute;
        width: 100%;
        left: 0;
        top: calc(100% + 6px);
        overflow: hidden;
        clip-path: inset(10% 50% 90% 50% round 10px);
        transition: clip-path 0.4s ease;
        z-index: 100;
        border: 1px solid rgba(35, 200, 122, 0.2);
        box-shadow: 0 10px 40px rgba(0, 0, 0, 0.4);
        max-height: 80vh;
        overflow-y: auto;
    }

    .mobile-nav-dropdown.is-open {
        clip-path: inset(0 0 0 0 round 10px);
    }

    /* 菜单项（参考 .menu-list）：交错出现 */
    .mobile-nav-item {
        --delay: 0.4s;
        --trdelay: 0.12s;
        display: block;
        padding: 12px 20px;
        color: white;
        text-decoration: none;
        border-radius: inherit;
        transition: background-color 0.2s, transform 0.4s, opacity 0.4s;
        position: relative;
        transform: translateY(30px);
        opacity: 0;
        font-size: 16px;
        border-bottom: 1px solid rgba(255, 255, 255, 0.08);
    }

    .mobile-nav-item:last-child {
        border-bottom: 0;
    }

    /* 二级菜单：父项可点击展开/收起 */
    .mobile-nav-group {
        position: relative;
        transform: translateY(30px);
        opacity: 0;
    }

    .mobile-nav-parent {
        -webkit-appearance: none;
        appearance: none;
        display: flex;
        align-items: center;
        justify-content: space-between;
        width: 100%;
        padding: 12px 20px;
        color: white;
        background: transparent;
        border: none;
        border-bottom: 1px solid rgba(255, 255, 255, 0.08);
        font-size: 16px;
        font: inherit;
        cursor: pointer;
        text-align: left;
        transition: background-color 0.2s, transform 0.4s, opacity 0.4s;
    }

    .mobile-nav-parent:hover {
        background-color: rgba(35, 200, 122, 0.2);
    }

    .mobile-nav-chevron {
        width: 10px;
        height: 10px;
        border-right: 2px solid currentColor;
        border-bottom: 2px solid currentColor;
        transform: rotate(45deg) translateY(-2px);
        transition: transform 0.25s ease;
    }

    .mobile-nav-parent.is-open .mobile-nav-chevron {
        transform: rotate(-135deg) translateY(2px);
    }

    .mobile-nav-sub {
        max-height: 0;
        overflow: hidden;
        transition: max-height 0.3s ease;
    }

    .mobile-nav-sub.is-open {
        max-height: 220px;
    }

    .mobile-nav-sub .mobile-nav-item.mobile-nav-sub-item {
        padding-left: 32px;
        font-size: 15px;
        border-radius: 0;
        transform: none;
        opacity: 1;
    }

    .mobile-nav-sub .mobile-nav-item.mobile-nav-sub-item::after {
        width: 90%;
        left: 32px;
        transform: translateX(-50%);
    }

    .mobile-nav-item::after {
        content: "";
        position: absolute;
        top: 100%;
        left: 50%;
        transform: translateX(-50%);
        height: 1px;
        background-color: rgba(255, 255, 255, 0.08);
        width: 95%;
    }

    .mobile-nav-item:hover {
        background-color: rgba(35, 200, 122, 0.2);
    }

    .mobile-nav-dropdown.is-open>.mobile-nav-item,
    .mobile-nav-dropdown.is-open>.mobile-nav-group {
        transform: translateY(0);
        opacity: 1;
    }

    .mobile-nav-dropdown.is-open>.mobile-nav-item:nth-child(1),
    .mobile-nav-dropdown.is-open>.mobile-nav-group:nth-child(4) {
        transition: transform 0.4s var(--delay), opacity 0.4s var(--delay), background-color 0.2s;
    }

    .mobile-nav-dropdown.is-open>.mobile-nav-item:nth-child(2) {
        transition: transform 0.4s calc(var(--delay) + var(--trdelay)), opacity 0.4s calc(var(--delay) + var(--trdelay)), background-color 0.2s;
    }

    .mobile-nav-dropdown.is-open>.mobile-nav-item:nth-child(3) {
        transition: transform 0.4s calc(var(--delay) + var(--trdelay) * 2), opacity 0.4s calc(var(--delay) + var(--trdelay) * 2), background-color 0.2s;
    }

    .mobile-nav-dropdown.is-open>.mobile-nav-group:nth-child(5) {
        transition: transform 0.4s calc(var(--delay) + var(--trdelay) * 3), opacity 0.4s calc(var(--delay) + var(--trdelay) * 3), background-color 0.2s;
    }

    .mobile-nav-dropdown.is-open>.mobile-nav-item:nth-child(6) {
        transition: transform 0.4s calc(var(--delay) + var(--trdelay) * 4), opacity 0.4s calc(var(--delay) + var(--trdelay) * 4), background-color 0.2s;
    }

    .mobile-nav-dropdown.is-open>.mobile-nav-item:nth-child(7) {
        transition: transform 0.4s calc(var(--delay) + var(--trdelay) * 5), opacity 0.4s calc(var(--delay) + var(--trdelay) * 5), background-color 0.2s;
    }

    .mobile-nav-dropdown.is-open>.mobile-nav-item:nth-child(8) {
        transition: transform 0.4s calc(var(--delay) + var(--trdelay) * 6), opacity 0.4s calc(var(--delay) + var(--trdelay) * 6), background-color 0.2s;
    }

    .mobile-nav-parent {
        transition: background-color 0.2s;
    }
}