/* Header styles for index_index.html - isolated to prevent conflicts */

:root {
    --brand-blue: #0b65c6;
    --brand-cyan: #3cc5ff;
    --container-width: min(1200px, 100vw);
    --font-heading: Arial, sans-serif;
    --font-body: Arial, sans-serif;
    --site-font: Arial, sans-serif;
}

@media (min-width: 1488px) and (max-width: 2067px) {
    body .site-header .container {
        padding-inline: clamp(28px, 3vw, 56px) !important;
    }

    body .site-header .header__inner {
        gap: 20px !important;
    }

    body .site-header .header__logo img {
        height: 58px !important;
    }

    body .site-header .header__nav {
        gap: clamp(18px, 2.2vw, 34px) !important;
        font-size: 15.2px !important;
        letter-spacing: 0.06em !important;
    }

    body .site-header .header__nav a {
        font-size: 15.2px !important;
        letter-spacing: 0.06em !important;
        white-space: nowrap !important;
    }

    body .site-header .header__actions {
        gap: 8px !important;
        padding-left: 10px !important;
    }

    body .site-header .lang-toggle {
        padding: 8px 12px !important;
        font-size: 14.5px !important;
    }

    body .site-header .lang-toggle span {
        font-size: 14.5px !important;
        letter-spacing: 0.04em !important;
    }
}

html,
body,
button,
input,
select,
textarea {
    font-family: Arial, sans-serif !important;
}

body :where(a, abbr, address, article, aside, b, blockquote, button, caption, cite, code, dd, details, dfn, div, dt, em, figcaption, footer, form, h1, h2, h3, h4, h5, h6, header, input, label, legend, li, main, nav, option, p, section, select, small, strong, summary, table, tbody, td, textarea, tfoot, th, thead, time, tr, ul, ol, span):not(.iconfont):not(.fa):not(.fas):not(.far):not(.fab):not(.glyphicon):not([class^="icon"]):not([class*=" icon"]):not([class*="icon-"]) {
    font-family: Arial, sans-serif !important;
}

.site-header {
    position: fixed !important;
    top: 0 !important;
    left: 0 !important;
    width: 100% !important;
    z-index: 20 !important;
    --header-scroll: 1;
    --header-fg: #0f1f3f;
    background: #fff !important;
    backdrop-filter: none !important;
    border-bottom: 1px solid rgba(15, 33, 74, 0.08) !important;
    box-shadow: 0 8px 24px rgba(8, 21, 61, 0.08) !important;
    transition: background-color 0.04s ease, box-shadow 0.04s ease, border-color 0.04s ease !important;
    font-family: Arial, sans-serif !important;
}

body {
    padding-top: 96px !important;
}

.site-header .container {
    width: 100% !important;
    max-width: none !important;
    padding-inline: clamp(20px, 4vw, 80px) !important;
}

.header__inner {
    display: flex !important;
    align-items: center !important;
    justify-content: space-between !important;
    padding: 14px 0 !important;
    gap: 32px !important;
}

.header__logo img {
    height: 68px !important;
}

.header__logo,
.header__actions {
    flex-shrink: 0 !important;
}

.header__nav {
    display: flex !important;
    flex: 1 !important;
    min-width: 0 !important;
    justify-content: center !important;
    gap: clamp(28px, 5vw, 60px) !important;
    flex-wrap: nowrap !important;
    font-weight: 600 !important;
    letter-spacing: 0.12em !important;
    text-transform: uppercase !important;
    color: #0f1f3f !important;
    font-size: 17.6px !important; /* 1.1rem = 17.6px (基于16px基准) */
}

.header__nav a {
    position: relative !important;
    padding-bottom: 4px !important;
    color: #0f1f3f !important;
    transition: color 0.2s ease !important;
    font-size: 17.6px !important; /* 1.1rem = 17.6px (基于16px基准) */
    text-transform: uppercase !important;
    letter-spacing: 0.12em !important;
    font-weight: 600 !important;
    white-space: nowrap !important;
    flex: 0 0 auto !important;
}

.header__nav a:hover,
.header__nav a:focus-visible,
.header__nav a[aria-current="true"],
.header__nav a.is-active {
    color: var(--brand-cyan) !important;
}

/* 渐变由 --header-scroll 控制，is-solid 仅用于 hover 等状态 */
.site-header.is-solid {
    background: #fff !important;
    border-bottom-color: rgba(15, 33, 74, 0.08) !important;
    box-shadow: 0 8px 24px rgba(8, 21, 61, 0.08) !important;
}

.site-header .header__nav a,
.site-header .lang-toggle,
.site-header .header__menu span {
    transition: color 0.3s ease, background-color 0.3s ease;
}

/* 导航与按钮颜色随滚动渐变（由 JS 设置 --header-fg） */
.site-header .header__nav a {
    color: #0f1f3f !important;
}

.site-header .lang-toggle {
    color: #0f1f3f !important;
    background: none !important;
}

.site-header .header__menu span {
    background: #0f1f3f !important;
}

.site-header.is-solid .header__nav a {
    color: #0f1f3f !important;
}

.site-header.is-solid .header__nav a:hover,
.site-header.is-solid .header__nav a:focus-visible,
.site-header.is-solid .header__nav a[aria-current="true"],
.site-header.is-solid .header__nav a.is-active {
    color: var(--brand-blue) !important;
}

.site-header.is-solid .header__menu span {
    background: #0f1f3f !important;
}

.header__actions {
    display: flex !important;
    align-items: center !important;
    gap: 12px !important;
    padding-left: clamp(12px, 2vw, 24px) !important;
}

.lang-toggle {
    width: auto !important;
    padding: 10px 18px !important;
    border-radius: 999px !important;
    display: inline-flex !important;
    align-items: center !important;
    justify-content: center !important;
    gap: 8px !important;
    color: inherit !important;
    background: none !important;
    border: none !important;
    font-size: 16px !important; /* 1rem = 16px (基于16px基准) */
}

.lang-toggle img {
    width: 20px;
    height: 20px;
    object-fit: contain;
}

.lang-toggle span {
    font-size: 16px !important; /* 1rem = 16px (基于16px基准) */
    letter-spacing: 0.08em !important;
    text-transform: none !important;
    font-weight: 400 !important;
}

.lang-toggle__caret {
    width: 8px;
    height: 8px;
    border-right: 2px solid currentColor;
    border-bottom: 2px solid currentColor;
    transform: rotate(45deg);
    margin-left: 0;
    transition: transform 0.2s ease;
}

.lang-toggle.is-open .lang-toggle__caret {
    transform: rotate(225deg);
}

.lang-toggle-wrapper {
    position: relative !important;
}

.lang-dropdown {
    position: absolute !important;
    top: calc(100% + 8px) !important;
    right: 0 !important;
    background: #fff !important;
    backdrop-filter: blur(10px) !important;
    border-radius: 8px !important;
    box-shadow: 0 8px 24px rgba(8, 21, 61, 0.12) !important;
    min-width: 140px !important;
    padding: 8px 0 !important;
    opacity: 0 !important;
    visibility: hidden !important;
    transform: translateY(-8px) !important;
    transition: opacity 0.2s ease, transform 0.2s ease, visibility 0.2s ease !important;
    z-index: 1000 !important;
    border: 1px solid rgba(15, 33, 74, 0.08) !important;
}

.lang-dropdown.is-open {
    opacity: 1 !important;
    visibility: visible !important;
    transform: translateY(0) !important;
}

.lang-option {
    display: flex !important;
    align-items: center !important;
    gap: 10px !important;
    padding: 10px 16px !important;
    color: #0f1f3f !important;
    text-decoration: none !important;
    font-size: 14px !important;
    font-weight: 500 !important;
    transition: background-color 0.2s ease !important;
    cursor: pointer !important;
}

.lang-option:hover {
    background-color: rgba(11, 101, 198, 0.08) !important;
}

.lang-option img {
    width: 18px !important;
    height: 18px !important;
    object-fit: contain !important;
}

.lang-option span {
    font-size: 14px !important;
    color: inherit !important;
}

.header__menu {
    display: none !important;
    flex-direction: column !important;
    gap: 4px !important;
}

.header__menu span {
    width: 24px !important;
    height: 2px !important;
    background: #fff !important;
}

.mobile-drawer {
    display: none;
    flex-direction: column;
    background: #fff;
    padding: 0 clamp(20px, 5vw, 40px);
    gap: 12px;
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease;
}

.mobile-drawer a {
    padding: 10px 0 !important;
    border-bottom: 1px solid rgba(15, 33, 74, 0.08) !important;
    color: #0f1f3f !important;
    text-transform: uppercase !important;
    letter-spacing: 0.12em !important;
    font-weight: 600 !important;
    font-size: 16px !important; /* 1rem = 16px (基于16px基准) */
}

.mobile-drawer.is-open {
    padding-block: 16px;
    max-height: 420px;
}

@media (max-width: 1487px) {
    body .site-header .container {
        padding-inline: clamp(20px, 3vw, 44px) !important;
    }

    body .site-header .header__inner {
        gap: 18px !important;
    }

    body .site-header .header__logo img {
        height: 58px !important;
    }

    body .site-header .header__nav {
        font-size: 16px !important; /* 1rem = 16px (基于16px基准) */
        gap: clamp(14px, 2vw, 28px) !important;
        letter-spacing: 0.06em !important;
        font-size: 15.2px !important;
        flex-wrap: nowrap !important;
    }

    body .site-header .header__nav a {
        font-size: 15.2px !important;
        letter-spacing: 0.06em !important;
        white-space: nowrap !important;
    }

    body .site-header .header__actions {
        gap: 8px !important;
        padding-left: 8px !important;
    }

    body .site-header .lang-toggle {
        padding: 8px 12px !important;
    }

    body .site-header .lang-toggle span {
        font-size: 15.2px !important; /* 0.95rem = 15.2px (基于16px基准) */
        letter-spacing: 0.06em !important;
    }
}

@media (max-width: 1200px) {
    .header__nav {
        display: none !important;
    }

    .header__menu {
        display: flex !important;
    }

    .mobile-drawer {
        display: flex !important;
    }
}

@media (max-width: 768px) {
    /* 确保手机端header样式统一，覆盖旧样式 */
    .site-header {
        background: #fff !important;
        border-bottom-color: rgba(15, 33, 74, 0.05) !important;
        box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08) !important;
    }

    .header__inner {
        padding: 10px 0 !important;
    }

    .header__logo img {
        height: 56px !important;
    }
    
    .site-header .header__nav a {
        color: #0f1f3f !important;
    }
    
    /* 手机端：汉堡菜单按钮始终为黑色（因为背景是白色） */
    .site-header .header__menu span,
    .site-header:not(.is-solid) .header__menu span,
    .site-header.is-solid .header__menu span {
        background: #0f1f3f !important;
    }
    
    .site-header .lang-toggle {
        color: #0f1f3f !important;
    }
    
    /* 确保body padding-top与header高度匹配，覆盖styles.css中的旧值 */
    body {
        padding-top: 76px !important; /* header高度 + 一些间距 */
    }
}

@media (max-width: 600px) {
    .header__inner {
        gap: 16px;
    }

    .lang-toggle span {
        display: none !important;
    }
}

@media (min-width: 1920px) {
    .site-header .container {
        padding-inline: clamp(60px, 5vw, 120px);
    }

    .header__inner {
        padding: 16px 0;
    }

    .header__logo img {
        height: 52px;
    }

    .header__nav {
        gap: clamp(40px, 4vw, 80px) !important;
        font-size: 19.2px !important; /* 1.2rem = 19.2px (基于16px基准) */
    }
}

/* Navigation restructure: top-level columns with About/Contact submenus. */
.site-header .header__nav-item {
    position: relative !important;
    display: flex !important;
    align-items: center !important;
    flex: 0 0 auto !important;
}

.site-header .header__nav-item--has-submenu > a {
    padding-right: 14px !important;
}

.site-header .header__nav-item--has-submenu > a::after {
    content: "" !important;
    position: absolute !important;
    right: 0 !important;
    top: 42% !important;
    width: 6px !important;
    height: 6px !important;
    border-right: 1.5px solid currentColor !important;
    border-bottom: 1.5px solid currentColor !important;
    transform: translateY(-50%) rotate(45deg) !important;
    transition: transform 0.2s ease !important;
}

.site-header .header__nav-item--has-submenu:hover > a::after,
.site-header .header__nav-item--has-submenu:focus-within > a::after {
    transform: translateY(-20%) rotate(225deg) !important;
}

.site-header .header__submenu {
    position: absolute !important;
    top: calc(100% + 18px) !important;
    left: 50% !important;
    display: grid !important;
    min-width: 210px !important;
    padding: 12px !important;
    background: rgba(255, 255, 255, 0.98) !important;
    border: 1px solid rgba(15, 33, 74, 0.08) !important;
    border-radius: 8px !important;
    box-shadow: 0 18px 36px rgba(8, 21, 61, 0.14) !important;
    opacity: 0 !important;
    visibility: hidden !important;
    pointer-events: none !important;
    transform: translate(-50%, -8px) !important;
    transition: opacity 0.18s ease, transform 0.18s ease, visibility 0.18s ease !important;
    z-index: 1001 !important;
}

.site-header .header__submenu::before {
    content: "" !important;
    position: absolute !important;
    left: 0 !important;
    right: 0 !important;
    top: -18px !important;
    height: 18px !important;
}

.site-header .header__nav-item:hover .header__submenu,
.site-header .header__nav-item:focus-within .header__submenu {
    opacity: 1 !important;
    visibility: visible !important;
    pointer-events: auto !important;
    transform: translate(-50%, 0) !important;
}

.site-header .header__submenu a,
body .site-header .header__submenu a {
    display: block !important;
    width: 100% !important;
    padding: 9px 12px !important;
    border-radius: 6px !important;
    color: #0f1f3f !important;
    font-size: 13.5px !important;
    line-height: 1.25 !important;
    letter-spacing: 0.02em !important;
    text-transform: none !important;
    font-weight: 600 !important;
    white-space: nowrap !important;
}

.site-header .header__submenu a:hover,
.site-header .header__submenu a:focus-visible {
    color: var(--brand-blue) !important;
    background: rgba(11, 101, 198, 0.08) !important;
    outline: none !important;
}

.site-header .mobile-drawer.is-open {
    max-height: 640px !important;
}
/* Slightly wider spacing for the restructured primary navigation. */
.site-header .header__nav {
    gap: clamp(36px, 5.8vw, 76px) !important;
}

@media (max-width: 1487px) {
    .site-header .header__nav {
        gap: clamp(22px, 2.8vw, 38px) !important;
    }
}

@media (min-width: 1488px) and (max-width: 2067px) {
    .site-header .header__nav {
        gap: clamp(28px, 3vw, 48px) !important;
    }
}

@media (min-width: 1920px) {
    .site-header .header__nav {
        gap: clamp(56px, 5vw, 100px) !important;
    }
}
/* Keep dropdowns below the header so the nav does not read as two rows. */
.site-header .header__inner,
.site-header .header__nav,
.site-header .header__nav-item {
    align-self: stretch !important;
}

.site-header .header__nav,
.site-header .header__nav-item {
    align-items: center !important;
}

.site-header .header__submenu {
    top: calc(100% + 8px) !important;
}

.site-header .header__submenu::before {
    top: -8px !important;
    height: 8px !important;
}
/* Lock header height across desktop resolutions. */
@media (min-width: 1201px) {
    body {
        padding-top: 96px !important;
    }

    .site-header .header__inner {
        height: 96px !important;
        padding-top: 0 !important;
        padding-bottom: 0 !important;
        align-items: center !important;
    }

    .site-header .header__logo img {
        height: 58px !important;
    }

    .site-header .header__nav,
    .site-header .header__nav-item {
        height: 100% !important;
        align-self: stretch !important;
        align-items: center !important;
    }

    .site-header .header__submenu {
        top: 100% !important;
    }

    .site-header .header__submenu::before {
        top: 0 !important;
        height: 0 !important;
    }
}

@media (max-width: 1200px) {
    body {
        padding-top: 76px !important;
    }

    .site-header .header__inner {
        height: 76px !important;
        padding-top: 0 !important;
        padding-bottom: 0 !important;
    }

    .site-header .header__logo img {
        height: 56px !important;
    }
}
/* Airier navigation rhythm after the menu restructure. */
@media (min-width: 1201px) {
    .site-header .header__nav {
        gap: clamp(54px, 7vw, 112px) !important;
    }

    .site-header .header__submenu {
        min-width: 230px !important;
        padding: 16px !important;
        gap: 6px !important;
    }

    .site-header .header__submenu a,
    body .site-header .header__submenu a {
        padding: 11px 14px !important;
    }
}

@media (min-width: 1201px) and (max-width: 1487px) {
    .site-header .header__nav {
        gap: clamp(32px, 4vw, 58px) !important;
    }
}

@media (min-width: 1488px) and (max-width: 2067px) {
    .site-header .header__nav {
        gap: clamp(52px, 4.8vw, 86px) !important;
    }
}

@media (min-width: 1920px) {
    .site-header .header__nav {
        gap: clamp(82px, 6vw, 150px) !important;
    }
}
/* Force wider nav spacing below 2068px; earlier media rules use higher specificity. */
@media (min-width: 1201px) and (max-width: 1487px) {
    body .site-header .header__nav {
        gap: clamp(36px, 4.4vw, 64px) !important;
    }
}

@media (min-width: 1488px) and (max-width: 2067px) {
    body .site-header .header__nav {
        gap: clamp(56px, 5.2vw, 92px) !important;
    }
}

/* Mobile header: keep the wide logo from dominating the first screen. */
@media (max-width: 600px) {
    body {
        padding-top: 64px !important;
    }

    body .site-header .container {
        padding-inline: 18px !important;
    }

    body .site-header .header__inner {
        height: 64px !important;
        gap: 12px !important;
    }

    body .site-header .header__logo img {
        height: 40px !important;
        width: auto !important;
        display: block !important;
    }
}

/* Mobile navigation accordion, modelled after the referenced menu interaction. */
@media (max-width: 1200px) {
    .site-header .mobile-drawer {
        position: fixed;
        z-index: 19;
        inset: 76px 0 0;
        display: flex;
        gap: 0;
        max-height: none;
        padding: 0 clamp(24px, 7vw, 42px);
        overflow-y: auto;
        background-color: #0b3c73;
        background-image:
            radial-gradient(circle at 100% 0, rgba(60, 197, 255, 0.24), transparent 38%),
            linear-gradient(155deg, #08274d 0%, #0b65c6 100%);
        opacity: 0;
        pointer-events: none;
        transform: translateY(-10px);
        transition: opacity 0.22s ease, transform 0.22s ease;
    }

    .site-header .mobile-drawer.is-open {
        max-height: none;
        padding: 18px clamp(24px, 7vw, 42px) 32px;
        opacity: 1;
        pointer-events: auto;
        transform: translateY(0);
    }

    .site-header .mobile-nav-item {
        width: 100%;
        border-bottom: 1px solid rgba(255, 255, 255, 0.22);
    }

    .site-header .mobile-nav-parent {
        display: flex;
        align-items: center;
        min-height: 62px;
    }

    .site-header .mobile-drawer .mobile-nav-link {
        flex: 1;
        min-width: 0;
        padding: 18px 0 !important;
        border: 0 !important;
        color: #fff !important;
        font-size: clamp(17px, 4.8vw, 22px) !important;
        line-height: 1.15;
    }

    .site-header .mobile-nav-item:not(.mobile-nav-item--has-children) .mobile-nav-link {
        display: block;
        min-height: 62px;
    }

    .site-header .mobile-nav-toggle {
        position: relative;
        flex: 0 0 48px;
        width: 48px;
        height: 48px;
        padding: 0;
        border: 0;
        background: transparent;
        color: #fff;
        cursor: pointer;
    }

    .site-header .mobile-nav-toggle::before,
    .site-header .mobile-nav-toggle::after {
        content: "";
        position: absolute;
        top: 50%;
        left: 50%;
        width: 22px;
        height: 2px;
        background: currentColor;
        transform: translate(-50%, -50%);
        transition: transform 0.2s ease;
    }

    .site-header .mobile-nav-toggle::after {
        transform: translate(-50%, -50%) rotate(90deg);
    }

    .site-header .mobile-nav-item.is-expanded .mobile-nav-toggle::after {
        transform: translate(-50%, -50%) rotate(0deg);
    }

    .site-header .mobile-submenu {
        max-height: 0;
        overflow: hidden;
        transition: max-height 0.24s ease;
    }

    .site-header .mobile-nav-item.is-expanded .mobile-submenu {
        max-height: 240px;
        padding-bottom: 12px;
    }

    .site-header .mobile-submenu a {
        display: block;
        padding: 9px 0 9px 18px !important;
        border: 0 !important;
        color: rgba(255, 255, 255, 0.8) !important;
        font-size: 14px !important;
        line-height: 1.35;
        letter-spacing: 0.07em !important;
        text-transform: uppercase !important;
    }
}

@media (max-width: 600px) {
    .site-header .mobile-drawer {
        top: 64px;
    }
}