/* ========== 基础重置 ========== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: "Microsoft YaHei", "微软雅黑", "PingFang SC", "Helvetica Neue", Arial, sans-serif;
    color: #1A2B4A;
    background: #fff;
    line-height: 1.6;
    overflow-x: hidden;
}

a {
    text-decoration: none;
    color: inherit;
}

ul,
ol {
    list-style: none;
}

img {
    max-width: 100%;
    display: block;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* ========== 顶部信息条 ========== */
.top-bar {
    background: #1F4E8C;
    color: #DCEBF7;
    font-size: 12px;
    padding: 6px 0;
    border-bottom: 1px solid #163B6B;
}

.top-bar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.top-bar .welcome {
    font-size: 12px;
}

.top-bar .top-links a {
    color: #DCEBF7;
    margin-left: 18px;
}

.top-bar .top-links a:hover {
    color: #FFB020;
}

/* ========== 主导航 ========== */
.header {
    background: #fff;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
    position: sticky;
    top: 0;
    z-index: 999;
}

.header .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 84px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 12px;
}

.logo-img-box {
    width: 52px;
    height: 52px;
    background: linear-gradient(135deg, #1F4E8C, #25B6D2);
    border-radius: 6px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: #fff;
    font-size: 22px;
    font-weight: bold;
}

.logo-text {
    display: flex;
    flex-direction: column;
}

.logo-text .cn {
    font-size: 22px;
    font-weight: bold;
    color: #1A2B4A;
    letter-spacing: 2px;
}

.logo-text .en {
    font-size: 11px;
    color: #8a99ab;
    letter-spacing: 1px;
    text-transform: uppercase;
}

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

.nav>li>a {
    display: block;
    padding: 0 22px;
    height: 84px;
    line-height: 84px;
    font-size: 16px;
    color: #1A2B4A;
    font-weight: 500;
    position: relative;
    transition: color 0.2s;
}

.nav>li>a:hover,
.nav>li.active>a {
    color: #1F4E8C;
}

.nav>li>a::after {
    content: "";
    position: absolute;
    bottom: 0;
    left: 50%;
    width: 0;
    height: 3px;
    background: #1F4E8C;
    transition: all 0.3s;
    transform: translateX(-50%);
}

.nav>li>a:hover::after,
.nav>li.active>a::after {
    width: 60%;
}

.nav .has-sub>a::before {
    content: "▾";
    font-size: 10px;
    margin-left: 6px;
    color: #8a99ab;
}

/* 二级菜单 */
.submenu {
    position: absolute;
    top: 84px;
    left: 0;
    background: #fff;
    min-width: 180px;
    box-shadow: 0 6px 20px rgba(0, 0, 0, 0.12);
    opacity: 0;
    visibility: hidden;
    transform: translateY(10px);
    transition: all 0.3s;
    z-index: 100;
}

.nav>li {
    position: relative;
}

.nav>li:hover .submenu {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.submenu li a {
    display: block;
    padding: 12px 20px;
    font-size: 14px;
    color: #555;
    border-bottom: 1px solid #EEF3F8;
    transition: all 0.2s;
}

.submenu li a:hover {
    background: #F0F7FD;
    color: #1F4E8C;
    padding-left: 26px;
}

.header-actions {
    display: flex;
    align-items: center;
    gap: 16px;
}

.search-btn,
.lang-btn {
    width: 36px;
    height: 36px;
    border: 1px solid #E4EDF5;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all 0.2s;
    background: #fff;
    font-size: 14px;
    color: #1A2B4A;
}

.search-btn:hover,
.lang-btn:hover {
    background: #1F4E8C;
    color: #fff;
    border-color: #1F4E8C;
}

/* ========== Banner 轮播 ========== */
.banner {
    position: relative;
    height: 560px;
    overflow: hidden;
    background: linear-gradient(135deg, #173A66 0%, #1F4E8C 100%);
}

.banner-slides {
    position: relative;
    width: 100%;
    height: 100%;
}

.banner-slide {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    opacity: 0;
    transition: opacity 0.8s;
    display: flex;
    align-items: center;
}

.banner-slide.active {
    opacity: 1;
}

.banner-slide .slide-bg {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 1;
}

.banner-slide .slide-bg::after {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, rgba(23, 58, 102, 0.85) 0%, rgba(23, 58, 102, 0.4) 60%, transparent 100%);
}

.banner-content {
    position: relative;
    z-index: 2;
    color: #fff;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    width: 100%;
}

.banner-content .sub-title {
    font-size: 16px;
    color: #7FE0F0;
    letter-spacing: 4px;
    margin-bottom: 16px;
    text-transform: uppercase;
}

.banner-content .main-title {
    font-size: 44px;
    font-weight: bold;
    line-height: 1.3;
    margin-bottom: 24px;
    text-shadow: 0 2px 12px rgba(0, 0, 0, 0.3);
}

.banner-content .desc {
    font-size: 18px;
    color: #D6E4F2;
    max-width: 560px;
    line-height: 1.8;
    margin-bottom: 32px;
}

.banner-btn {
    display: inline-block;
    padding: 14px 38px;
    background: #FFB020;
    color: #1A2B4A;
    font-size: 15px;
    border-radius: 4px;
    transition: all 0.3s;
    border: 2px solid #FFB020;
}

.banner-btn:hover {
    background: #E89A0F;
    border-color: #E89A0F;
}

.banner-arrows {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    width: 100%;
    z-index: 3;
    display: flex;
    justify-content: space-between;
    padding: 0 20px;
}

.banner-arrows .arrow {
    width: 48px;
    height: 48px;
    background: rgba(255, 255, 255, 0.15);
    border: 1px solid rgba(255, 255, 255, 0.3);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: #fff;
    cursor: pointer;
    font-size: 20px;
    transition: all 0.3s;
}

.banner-arrows .arrow:hover {
    background: #1F4E8C;
    border-color: #1F4E8C;
}

.banner-dots {
    position: absolute;
    bottom: 30px;
    left: 50%;
    transform: translateX(-50%);
    z-index: 3;
    display: flex;
    gap: 12px;
}

.banner-dots .dot {
    width: 40px;
    height: 3px;
    background: rgba(255, 255, 255, 0.3);
    cursor: pointer;
    transition: all 0.3s;
}

.banner-dots .dot.active {
    background: #fff;
}

/* ========== 通用区块标题 ========== */
.section {
    padding: 70px 0;
}

.section-header {
    text-align: center;
    margin-bottom: 50px;
}

.section-header .en-title {
    font-size: 14px;
    color: #1F4E8C;
    letter-spacing: 4px;
    text-transform: uppercase;
    margin-bottom: 10px;
    font-weight: 600;
}

.section-header .cn-title {
    font-size: 32px;
    font-weight: bold;
    color: #1A2B4A;
    margin-bottom: 16px;
}

.section-header .cn-title span {
    color: #1F4E8C;
}

.section-header .divider {
    width: 50px;
    height: 3px;
    background: #1F4E8C;
    margin: 0 auto 18px;
}

.section-header .desc {
    font-size: 15px;
    color: #5C6E86;
    max-width: 720px;
    margin: 0 auto;
    line-height: 1.8;
}

/* ========== 关于粤科 ========== */
.about {
    background: #F4F8FB;
}

.about-wrap {
    display: flex;
    gap: 50px;
    align-items: stretch;
}

.about-media {
    flex: 0 0 50%;
    position: relative;
}

.about-media img {
    width: 100%;
    height: 380px;
    object-fit: cover;
    border-radius: 4px;
}

.about-media .play-btn {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 70px;
    height: 70px;
    background: rgba(31, 78, 140, 0.9);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all 0.3s;
}

.about-media .play-btn::after {
    content: "";
    width: 0;
    height: 0;
    border-left: 18px solid #fff;
    border-top: 12px solid transparent;
    border-bottom: 12px solid transparent;
    margin-left: 6px;
}

.about-media .play-btn:hover {
    background: #1F4E8C;
    transform: translate(-50%, -50%) scale(1.1);
}

.about-info {
    flex: 1;
    display: flex;
    flex-direction: column;
}

.about-info .sub-en {
    font-size: 13px;
    color: #1F4E8C;
    letter-spacing: 3px;
    text-transform: uppercase;
    margin-bottom: 8px;
}

.about-info h2 {
    font-size: 28px;
    color: #1A2B4A;
    margin-bottom: 20px;
}

.about-info p {
    font-size: 14px;
    color: #5C6E86;
    line-height: 2;
    margin-bottom: 24px;
}

.about-features {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 16px;
    margin-bottom: 24px;
}

.about-feature {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 16px;
    background: #fff;
    border-radius: 4px;
    transition: all 0.3s;
    border: 1px solid #E4EDF5;
}

.about-feature:hover {
    border-color: #1F4E8C;
    box-shadow: 0 4px 16px rgba(31, 78, 140, 0.1);
    transform: translateY(-2px);
}

.about-feature .ico {
    width: 44px;
    height: 44px;
    background: linear-gradient(135deg, #1F4E8C, #25B6D2);
    border-radius: 6px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: #fff;
    font-size: 20px;
    flex-shrink: 0;
}

.about-feature .txt {
    font-size: 14px;
    color: #1A2B4A;
    font-weight: 600;
}

.about-more {
    display: inline-block;
    align-self: flex-start;
    padding: 12px 32px;
    background: #FFB020;
    color: #1A2B4A;
    font-size: 14px;
    border-radius: 4px;
    transition: all 0.3s;
}

.about-more:hover {
    background: #E89A0F;
    transform: translateX(4px);
}

/* ========== 产品中心 ========== */
.products {
    background: #fff;
}

.product-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
}

.product-card {
    background: #fff;
    border: 1px solid #E4EDF5;
    border-radius: 4px;
    overflow: hidden;
    transition: all 0.3s;
    cursor: pointer;
}

.product-card:hover {
    box-shadow: 0 8px 30px rgba(31, 78, 140, 0.15);
    transform: translateY(-4px);
}

.product-card .img-wrap {
    height: 200px;
    overflow: hidden;
    position: relative;
}

.product-card .img-wrap img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.5s;
}

.product-card:hover .img-wrap img {
    transform: scale(1.08);
}

.product-card .img-wrap::after {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(to top, rgba(23, 58, 102, 0.3), transparent 50%);
    opacity: 0;
    transition: opacity 0.3s;
}

.product-card:hover .img-wrap::after {
    opacity: 1;
}

.product-card .info {
    padding: 16px;
    background: linear-gradient(135deg, #1F4E8C, #163B6B);
}

.product-card .info .name {
    font-size: 16px;
    color: #fff;
    font-weight: 600;
    margin-bottom: 6px;
}

.product-card .info .en {
    font-size: 11px;
    color: #8a99ab;
    text-transform: uppercase;
    letter-spacing: 1px;
}

/* ========== 应用领域 ========== */
.applications {
    background: #F4F8FB;
}

.app-grid {
    display: grid;
    grid-template-columns: repeat(5, 1fr);
    gap: 20px;
}

.app-item {
    position: relative;
    height: 160px;
    overflow: hidden;
    border-radius: 4px;
    cursor: pointer;
}

.app-item img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.5s;
}

.app-item:hover img {
    transform: scale(1.1);
}

.app-item .overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, rgba(23, 58, 102, 0.72), rgba(23, 58, 102, 0.5));
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    color: #fff;
    transition: all 0.3s;
}

.app-item:hover .overlay {
    background: linear-gradient(135deg, rgba(31, 78, 140, 0.85), rgba(37, 182, 210, 0.75));
}

.app-item .ico {
    font-size: 28px;
    margin-bottom: 8px;
}

.app-item .name {
    font-size: 16px;
    font-weight: 600;
}

.app-item .en-name {
    font-size: 11px;
    opacity: 0.8;
    margin-top: 4px;
    text-transform: uppercase;
    letter-spacing: 1px;
}

/* ========== 新闻中心 ========== */
.news {
    background: #fff;
}

.news-wrap {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 40px;
}

.news-featured {
    position: relative;
    overflow: hidden;
    border-radius: 4px;
    cursor: pointer;
}

.news-featured img {
    width: 100%;
    height: 320px;
    object-fit: cover;
    transition: transform 0.5s;
}

.news-featured:hover img {
    transform: scale(1.05);
}

.news-featured .overlay {
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    padding: 24px;
    background: linear-gradient(to top, rgba(23, 58, 102, 0.95), transparent);
    color: #fff;
}

.news-featured .date {
    font-size: 14px;
    color: #7FE0F0;
    margin-bottom: 8px;
}

.news-featured .title {
    font-size: 18px;
    font-weight: 600;
    line-height: 1.5;
}

.news-list {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.news-item {
    display: flex;
    gap: 20px;
    padding-bottom: 20px;
    border-bottom: 1px dashed #E4EDF5;
    cursor: pointer;
    transition: all 0.2s;
}

.news-item:last-child {
    border-bottom: none;
}

.news-item:hover .news-title {
    color: #1F4E8C;
}

.news-date {
    flex-shrink: 0;
    width: 80px;
    text-align: center;
    border-right: 2px solid #1F4E8C;
    padding-right: 16px;
}

.news-date .day {
    font-size: 32px;
    font-weight: bold;
    color: #1A2B4A;
    line-height: 1;
}

.news-date .ym {
    font-size: 12px;
    color: #999;
    margin-top: 4px;
}

.news-content {
    flex: 1;
}

.news-title {
    font-size: 16px;
    font-weight: 600;
    color: #1A2B4A;
    margin-bottom: 8px;
    transition: color 0.2s;
    line-height: 1.5;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.news-desc {
    font-size: 13px;
    color: #5C6E86;
    line-height: 1.7;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

/* ========== 为什么选择我们 ========== */
.why-us {
    background: linear-gradient(135deg, #173A66 0%, #1F4E8C 50%, #1E86A8 100%);
    color: #fff;
    padding: 70px 0;
}

.why-us .section-header .cn-title {
    color: #fff;
}

.why-us .section-header .desc {
    color: rgba(255, 255, 255, 0.78);
}

.why-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
}

.why-card {
    text-align: center;
    padding: 36px 20px;
    background: rgba(255, 255, 255, 0.04);
    border: 1px solid rgba(255, 255, 255, 0.08);
    border-radius: 4px;
    transition: all 0.3s;
}

.why-card:hover {
    background: rgba(31, 78, 140, 0.15);
    border-color: #1F4E8C;
    transform: translateY(-4px);
}

.why-card .num {
    font-size: 42px;
    font-weight: bold;
    color: #FFB020;
    margin-bottom: 12px;
}

.why-card .num span {
    font-size: 20px;
}

.why-card .title {
    font-size: 16px;
    font-weight: 600;
    margin-bottom: 8px;
}

.why-card .desc {
    font-size: 13px;
    color: rgba(255, 255, 255, 0.72);
    line-height: 1.7;
}

/* ========== 客户案例 ========== */
.clients {
    background: #F4F8FB;
}

.clients-marquee {
    overflow: hidden;
    position: relative;
}

.clients-track {
    display: flex;
    gap: 30px;
    animation: marquee 30s linear infinite;
    width: max-content;
}

.clients-track:hover {
    animation-play-state: paused;
}

@keyframes marquee {
    0% {
        transform: translateX(0);
    }

    100% {
        transform: translateX(-50%);
    }
}

.client-item {
    flex-shrink: 0;
    width: 200px;
    height: 100px;
    background: #fff;
    border: 1px solid #E4EDF5;
    border-radius: 4px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 14px;
    color: #8a99ab;
    transition: all 0.3s;
}

.client-item:hover {
    border-color: #1F4E8C;
    color: #1F4E8C;
    box-shadow: 0 4px 16px rgba(31, 78, 140, 0.1);
}

/* ========== CTA 区块 ========== */
.cta-band {
    background: linear-gradient(135deg, #1F4E8C 0%, #25B6D2 100%);
    padding: 50px 0;
    color: #fff;
    text-align: center;
}

.cta-band h3 {
    font-size: 28px;
    font-weight: bold;
    margin-bottom: 12px;
}

.cta-band p {
    font-size: 15px;
    opacity: 0.9;
    margin-bottom: 24px;
}

.cta-band .cta-btn {
    display: inline-block;
    padding: 14px 40px;
    background: #FFB020;
    color: #1A2B4A;
    font-size: 15px;
    font-weight: 600;
    border-radius: 4px;
    transition: all 0.3s;
}

.cta-band .cta-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(0, 0, 0, 0.2);
}

/* ========== Footer ========== */
.footer {
    background: #F4F8FB;
    color: #5C6E86;
    padding-top: 60px;
    border-top: 1px solid #E4EDF5;
}

.footer-main {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1.5fr;
    gap: 40px;
    padding-bottom: 40px;
    border-bottom: 1px solid #DCE7F0;
}

.footer-col h4 {
    color: #1A2B4A;
    font-size: 16px;
    margin-bottom: 20px;
    font-weight: 600;
}

.footer-col p {
    font-size: 13px;
    line-height: 2;
    color: #5C6E86;
}

.footer-col p .ico {
    color: #1F4E8C;
    margin-right: 8px;
}

.footer-col ul li {
    margin-bottom: 10px;
}

.footer-col ul li a {
    font-size: 13px;
    color: #5C6E86;
    transition: color 0.2s;
}

.footer-col ul li a:hover {
    color: #1F4E8C;
}

.footer-contact .qr {
    width: 120px;
    height: 120px;
    background: #fff;
    border-radius: 4px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: #1A2B4A;
    font-size: 12px;
    text-align: center;
    margin-top: 10px;
}

.footer-bottom {
    padding: 20px 0;
    text-align: center;
    font-size: 12px;
    color: #8A99AB;
}

.footer-bottom a {
    color: #8A99AB;
    margin: 0 8px;
}

.footer-bottom a:hover {
    color: #1F4E8C;
}

/* ========== 侧边悬浮 ========== */
.side-tools {
    position: fixed;
    right: 20px;
    bottom: 80px;
    z-index: 99;
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.side-tool {
    width: 50px;
    height: 50px;
    background: #1F4E8C;
    color: #fff;
    border-radius: 6px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all 0.3s;
    box-shadow: 0 4px 12px rgba(31, 78, 140, 0.3);
    font-size: 12px;
    border: none;
}

.side-tool:hover {
    background: #163B6B;
    transform: translateX(-4px);
}

.side-tool.top {
    background: rgba(31, 78, 140, 0.9);
}

/* ========== 响应式 ========== */
@media (max-width: 1024px) {
    .nav>li>a {
        padding: 0 16px;
        font-size: 15px;
    }

    .product-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .app-grid {
        grid-template-columns: repeat(4, 1fr);
    }

    .why-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .footer-main {
        grid-template-columns: 1fr 1fr;
    }

    .about-wrap {
        flex-direction: column;
    }

    .about-media {
        flex: none;
    }

    .news-wrap {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 768px) {
    .top-bar {
        display: none;
    }

    .header .container {
        height: 64px;
    }

    .nav {
        display: none;
    }

    .logo-text .cn {
        font-size: 18px;
    }

    .banner {
        height: 380px;
    }

    .banner-content .main-title {
        font-size: 28px;
    }

    .banner-content .desc {
        font-size: 14px;
    }

    .section {
        padding: 40px 0;
    }

    .section-header .cn-title {
        font-size: 24px;
    }

    .product-grid {
        grid-template-columns: 1fr;
    }

    .app-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .why-grid {
        grid-template-columns: 1fr;
    }

    .footer-main {
        grid-template-columns: 1fr;
        gap: 30px;
    }

    .about-features {
        grid-template-columns: 1fr;
    }

    .news-wrap {
        grid-template-columns: 1fr;
    }

    .news-featured {
        height: 200px;
    }

    .prod-grid {
        grid-template-columns: 1fr;
    }

    .art-article-grid {
        grid-template-columns: 1fr;
    }

    .art-layout {
        grid-template-columns: 1fr;
    }

    .art-filter-bar {
        flex-direction: column;
        align-items: stretch;
    }

    .art-search-input {
        width: 100%;
        flex: 1;
    }

    .art-side-nav {
        display: none;
    }
}

/* ========== 移动端汉堡菜单按钮 ========== */
.nav-toggle {
    display: none;
    flex-direction: column;
    justify-content: center;
    gap: 5px;
    width: 40px;
    height: 40px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 0;
    position: absolute;
    right: 16px;
    top: 50%;
    transform: translateY(-50%);
    z-index: 1200;
}

.nav-toggle span {
    display: block;
    width: 26px;
    height: 3px;
    background: #1F4E8C;
    border-radius: 2px;
    transition: all 0.3s ease;
    margin: 0 auto;
}

.nav-toggle.active span:nth-child(1) {
    transform: rotate(45deg) translate(6px, 6px);
}

.nav-toggle.active span:nth-child(2) {
    opacity: 0;
}

.nav-toggle.active span:nth-child(3) {
    transform: rotate(-45deg) translate(6px, -6px);
}

/* ========== 移动端导航抽屉 ========== */
.mobile-nav-overlay {
    display: none;
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.5);
    z-index: 1300;
    opacity: 0;
    transition: opacity 0.3s ease;
}

.mobile-nav-overlay.active {
    display: block;
    opacity: 1;
}

.mobile-nav {
    position: fixed;
    top: 0;
    right: -280px;
    width: 280px;
    height: 100vh;
    background: #fff;
    z-index: 1400;
    overflow-y: auto;
    transition: right 0.35s cubic-bezier(0.4, 0, 0.2, 1);
    box-shadow: -4px 0 20px rgba(0, 0, 0, 0.15);
}

.mobile-nav.active {
    right: 0;
}

.mobile-nav-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 18px 20px;
    background: #1F4E8C;
    color: #fff;
}

.mobile-nav-title {
    font-size: 17px;
    font-weight: 600;
}

.mobile-nav-close {
    background: none;
    border: none;
    color: #fff;
    font-size: 28px;
    line-height: 1;
    cursor: pointer;
    padding: 0;
    width: 32px;
    height: 32px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.mobile-nav-list {
    list-style: none;
    margin: 0;
    padding: 0;
}

.mobile-nav-item {
    border-bottom: 1px solid #E9EFF6;
    position: relative;
}

.mobile-nav-item>a {
    display: block;
    padding: 15px 20px;
    font-size: 15px;
    color: #1A2B4A;
    text-decoration: none;
    transition: all 0.2s;
}

.mobile-nav-item>a:hover,
.mobile-nav-item>a:active {
    background: #EDF4FB;
    color: #1F4E8C;
}

.mobile-sub-toggle {
    position: absolute;
    right: 8px;
    top: 50%;
    transform: translateY(-50%);
    width: 36px;
    height: 36px;
    border: none;
    background: none;
    font-size: 22px;
    color: #999;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: transform 0.3s;
}

.mobile-sub-toggle.active {
    transform: translateY(-50%) rotate(45deg);
    color: #1F4E8C;
}

.mobile-sub-nav {
    list-style: none;
    margin: 0;
    padding: 0;
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.35s ease;
    background: #F4F8FB;
}

.mobile-sub-nav.active {
    max-height: 500px;
}

.mobile-sub-nav li a {
    display: block;
    padding: 12px 20px 12px 36px;
    font-size: 14px;
    color: #5C6E86;
    text-decoration: none;
    border-bottom: 1px solid #E9EFF6;
    transition: all 0.2s;
}

.mobile-sub-nav li a:hover {
    color: #1F4E8C;
    background: #EDF4FB;
}

/* 桌面端隐藏汉堡按钮 */
@media (min-width: 769px) {
    .nav-toggle {
        display: none;
    }
}

/* 移动端显示汉堡按钮 */
@media (max-width: 768px) {
    .nav-toggle {
        display: flex;
    }

    .header .container {
        position: relative;
    }
}