/* 全局重置与基础样式 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: system-ui, 'Segoe UI', Roboto, 'Helvetica Neue', sans-serif;
}

body {
    background: linear-gradient(135deg, #f5f7fa 0%, #e8ecf1 100%);
    color: #1e293b;
    line-height: 1.7;
    font-size: 16px;
    transition: background 0.3s, color 0.3s;
}

a {
    color: #1a3a5c;
    text-decoration: none;
    transition: color 0.2s;
}

a:hover {
    color: #2563eb;
}

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

/* 导航吸顶 - 毛玻璃效果 */
.navbar {
    position: sticky;
    top: 0;
    z-index: 1000;
    background: rgba(255, 255, 255, 0.85);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    box-shadow: 0 2px 20px rgba(0, 0, 0, 0.08);
    padding: 12px 0;
    transition: all 0.3s;
}

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

.logo {
    font-size: 1.8rem;
    font-weight: 700;
    color: #1a3a5c;
    letter-spacing: 1px;
}

.logo span {
    color: #2563eb;
}

.nav-links {
    display: flex;
    gap: 28px;
    list-style: none;
    font-weight: 500;
}

.nav-links a {
    padding: 6px 0;
    border-bottom: 2px solid transparent;
    transition: 0.2s;
}

.nav-links a:hover {
    border-bottom-color: #2563eb;
}

.menu-toggle {
    display: none;
    background: none;
    border: none;
    font-size: 1.8rem;
    cursor: pointer;
    color: #1a3a5c;
}

/* 面包屑 */
.breadcrumb {
    background: rgba(238, 242, 246, 0.8);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    padding: 14px 0;
    font-size: 0.9rem;
}

.breadcrumb a {
    color: #2563eb;
}

.breadcrumb span {
    color: #64748b;
}

/* Banner轮播 - 渐变背景 */
.banner {
    position: relative;
    overflow: hidden;
    height: 480px;
    background: linear-gradient(135deg, #1a3a5c 0%, #2563eb 50%, #1e40af 100%);
    color: #fff;
}

.banner-slide {
    position: absolute;
    inset: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    transition: opacity 1s ease;
    padding: 0 20px;
    text-align: center;
}

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

.banner h1 {
    font-size: 3.2rem;
    font-weight: 700;
    margin-bottom: 16px;
    text-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
}

.banner p {
    font-size: 1.3rem;
    max-width: 700px;
    margin: 0 auto;
    opacity: 0.9;
}

.banner-dots {
    position: absolute;
    bottom: 24px;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    gap: 12px;
}

.banner-dots span {
    width: 14px;
    height: 14px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.5);
    cursor: pointer;
    transition: 0.3s;
}

.banner-dots span.active {
    background: #fff;
    transform: scale(1.2);
}

/* 通用区块 */
section {
    padding: 60px 0;
}

.section-title {
    text-align: center;
    margin-bottom: 48px;
}

.section-title h2 {
    font-size: 2.2rem;
    color: #1a3a5c;
    margin-bottom: 12px;
}

.section-title p {
    color: #64748b;
    max-width: 600px;
    margin: 0 auto;
}

.grid-2 {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 32px;
}

.grid-3 {
    display: grid;
    grid-template-columns: 1fr 1fr 1fr;
    gap: 28px;
}

.grid-4 {
    display: grid;
    grid-template-columns: 1fr 1fr 1fr 1fr;
    gap: 24px;
}

/* 圆角卡片 - 毛玻璃效果 */
.card {
    background: rgba(255, 255, 255, 0.85);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    border-radius: 20px;
    padding: 28px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.06);
    transition: transform 0.3s, box-shadow 0.3s, background 0.3s;
    border: 1px solid rgba(255, 255, 255, 0.3);
}

.card:hover {
    transform: translateY(-8px);
    box-shadow: 0 16px 40px rgba(0, 0, 0, 0.12);
    background: rgba(255, 255, 255, 0.95);
}

.card h3 {
    font-size: 1.4rem;
    margin-bottom: 12px;
    color: #1a3a5c;
}

.card h4 {
    font-size: 1.1rem;
    margin-bottom: 8px;
    color: #2563eb;
}

.card p {
    color: #475569;
    margin-bottom: 12px;
}

.card svg {
    width: 48px;
    height: 48px;
    margin-bottom: 16px;
}

/* 按钮 */
.btn {
    display: inline-block;
    background: linear-gradient(135deg, #2563eb, #1d4ed8);
    color: #fff;
    padding: 10px 24px;
    border-radius: 30px;
    font-weight: 500;
    transition: transform 0.3s, box-shadow 0.3s, background 0.3s;
    border: none;
    cursor: pointer;
    box-shadow: 0 4px 12px rgba(37, 99, 235, 0.3);
}

.btn:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 24px rgba(37, 99, 235, 0.4);
    background: linear-gradient(135deg, #1d4ed8, #1a3a5c);
}

.btn-outline {
    background: transparent;
    border: 2px solid #2563eb;
    color: #2563eb;
    box-shadow: none;
}

.btn-outline:hover {
    background: #2563eb;
    color: #fff;
    box-shadow: 0 4px 12px rgba(37, 99, 235, 0.3);
}

/* 关于/品牌介绍 */
.about {
    background: rgba(255, 255, 255, 0.6);
    backdrop-filter: blur(6px);
    -webkit-backdrop-filter: blur(6px);
}

.about .grid-2 {
    align-items: center;
}

.about-text h2 {
    font-size: 2rem;
    margin-bottom: 20px;
    color: #1a3a5c;
}

.about-text p {
    margin-bottom: 16px;
    color: #475569;
}

.about-stats {
    display: flex;
    gap: 40px;
    margin-top: 24px;
}

.about-stats div {
    text-align: center;
}

.about-stats strong {
    font-size: 2rem;
    color: #2563eb;
    display: block;
}

.about-stats span {
    color: #64748b;
}

/* 产品 */
.products {
    background: rgba(248, 250, 252, 0.7);
    backdrop-filter: blur(4px);
    -webkit-backdrop-filter: blur(4px);
}

/* 解决方案 */
.solutions {
    background: rgba(255, 255, 255, 0.6);
    backdrop-filter: blur(6px);
    -webkit-backdrop-filter: blur(6px);
}

/* 案例评价 */
.cases {
    background: rgba(248, 250, 252, 0.7);
    backdrop-filter: blur(4px);
    -webkit-backdrop-filter: blur(4px);
}

.case-item {
    border-left: 4px solid #2563eb;
    padding-left: 20px;
    margin-bottom: 28px;
}

.case-item h4 {
    color: #1a3a5c;
}

.testimonial {
    background: rgba(255, 255, 255, 0.85);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    border-radius: 20px;
    padding: 24px;
    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.05);
    font-style: italic;
    position: relative;
    border: 1px solid rgba(255, 255, 255, 0.3);
}

.testimonial::before {
    content: '"';
    font-size: 3rem;
    color: #2563eb;
    position: absolute;
    top: -10px;
    left: 16px;
    opacity: 0.3;
}

/* 新闻/文章 */
.news {
    background: rgba(255, 255, 255, 0.6);
    backdrop-filter: blur(6px);
    -webkit-backdrop-filter: blur(6px);
}

.article-item {
    margin-bottom: 32px;
    padding-bottom: 20px;
    border-bottom: 1px solid rgba(226, 232, 240, 0.8);
}

.article-item h4 {
    font-size: 1.2rem;
    color: #1a3a5c;
    margin-bottom: 6px;
}

.article-item .meta {
    color: #94a3b8;
    font-size: 0.9rem;
    margin-bottom: 8px;
}

.article-item p {
    color: #475569;
}

.read-more {
    color: #2563eb;
    font-weight: 500;
}

/* FAQ */
.faq {
    background: rgba(248, 250, 252, 0.7);
    backdrop-filter: blur(4px);
    -webkit-backdrop-filter: blur(4px);
}

.faq-item {
    margin-bottom: 16px;
    border: 1px solid rgba(226, 232, 240, 0.8);
    border-radius: 16px;
    overflow: hidden;
    background: rgba(255, 255, 255, 0.85);
    backdrop-filter: blur(6px);
    -webkit-backdrop-filter: blur(6px);
    transition: box-shadow 0.3s;
}

.faq-item:hover {
    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.06);
}

.faq-question {
    background: transparent;
    padding: 18px 24px;
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-weight: 600;
    color: #1a3a5c;
    transition: 0.2s;
    border: none;
    width: 100%;
    text-align: left;
    font-size: 1rem;
}

.faq-question:hover {
    background: rgba(241, 245, 249, 0.6);
}

.faq-question::after {
    content: '+';
    font-size: 1.5rem;
    color: #2563eb;
    transition: 0.3s;
}

.faq-item.open .faq-question::after {
    content: '−';
}

.faq-answer {
    padding: 0 24px 18px;
    color: #475569;
    display: none;
}

.faq-item.open .faq-answer {
    display: block;
}

/* HowTo */
.howto {
    background: rgba(255, 255, 255, 0.6);
    backdrop-filter: blur(6px);
    -webkit-backdrop-filter: blur(6px);
}

.howto-steps {
    list-style: none;
    counter-reset: step;
}

.howto-steps li {
    counter-increment: step;
    padding: 18px 0 18px 50px;
    position: relative;
    border-bottom: 1px solid rgba(226, 232, 240, 0.8);
}

.howto-steps li::before {
    content: counter(step);
    position: absolute;
    left: 0;
    top: 18px;
    width: 36px;
    height: 36px;
    background: linear-gradient(135deg, #2563eb, #1d4ed8);
    color: #fff;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    box-shadow: 0 4px 8px rgba(37, 99, 235, 0.3);
}

.howto-steps li strong {
    display: block;
    color: #1a3a5c;
    margin-bottom: 4px;
}

/* 联系 */
.contact {
    background: linear-gradient(135deg, #1a3a5c 0%, #1e40af 100%);
    color: #fff;
}

.contact .grid-3 {
    color: #e2e8f0;
}

.contact h3 {
    color: #fff;
    margin-bottom: 16px;
}

.contact a {
    color: #93c5fd;
}

.contact a:hover {
    color: #fff;
}

/* 底部 */
footer {
    background: #0f172a;
    color: #94a3b8;
    padding: 40px 0 20px;
}

footer .grid-4 {
    font-size: 0.95rem;
}

footer h4 {
    color: #fff;
    margin-bottom: 14px;
}

footer ul {
    list-style: none;
}

footer ul li {
    margin-bottom: 8px;
}

footer ul li a {
    color: #94a3b8;
}

footer ul li a:hover {
    color: #fff;
}

.footer-bottom {
    border-top: 1px solid #1e293b;
    padding-top: 20px;
    margin-top: 32px;
    text-align: center;
    font-size: 0.85rem;
}

/* 返回顶部 */
.back-top {
    position: fixed;
    bottom: 40px;
    right: 40px;
    background: linear-gradient(135deg, #2563eb, #1d4ed8);
    color: #fff;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.3s, visibility 0.3s, transform 0.3s;
    z-index: 999;
    border: none;
    font-size: 1.5rem;
    box-shadow: 0 4px 16px rgba(37, 99, 235, 0.4);
}

.back-top.show {
    opacity: 1;
    visibility: visible;
}

.back-top:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 24px rgba(37, 99, 235, 0.5);
}

/* 暗黑模式 */
.dark-mode-toggle {
    position: fixed;
    bottom: 100px;
    right: 40px;
    background: #1e293b;
    color: #fff;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    z-index: 999;
    border: none;
    font-size: 1.2rem;
    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.2);
    transition: background 0.3s, transform 0.3s;
}

.dark-mode-toggle:hover {
    transform: scale(1.1);
}

body.dark {
    background: linear-gradient(135deg, #0f172a 0%, #1e293b 100%);
    color: #e2e8f0;
}

body.dark .navbar {
    background: rgba(30, 41, 59, 0.85);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    box-shadow: 0 2px 20px rgba(0, 0, 0, 0.4);
}

body.dark .breadcrumb {
    background: rgba(30, 41, 59, 0.8);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
}

body.dark .breadcrumb a {
    color: #93c5fd;
}

body.dark .card,
body.dark .about,
body.dark .solutions,
body.dark .news,
body.dark .howto,
body.dark .faq-item,
body.dark .faq-question,
body.dark .testimonial {
    background: rgba(30, 41, 59, 0.85);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    color: #e2e8f0;
    border-color: rgba(51, 65, 85, 0.5);
}

body.dark .card h3,
body.dark .about-text h2,
body.dark .section-title h2,
body.dark .faq-question,
body.dark .case-item h4,
body.dark .article-item h4 {
    color: #f1f5f9;
}

body.dark .card p,
body.dark .about-text p,
body.dark .faq-answer,
body.dark .article-item p,
body.dark .howto-steps li,
body.dark .howto ul,
body.dark .howto p {
    color: #cbd5e1;
}

body.dark .btn-outline {
    border-color: #93c5fd;
    color: #93c5fd;
}

body.dark .contact {
    background: linear-gradient(135deg, #0f172a 0%, #1e293b 100%);
}

body.dark .banner {
    background: linear-gradient(135deg, #0f172a 0%, #1e293b 50%, #1a3a5c 100%);
}

/* 响应式 */
@media (max-width: 768px) {
    .nav-links {
        display: none;
        flex-direction: column;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: rgba(255, 255, 255, 0.95);
        backdrop-filter: blur(12px);
        -webkit-backdrop-filter: blur(12px);
        padding: 20px;
        box-shadow: 0 8px 24px rgba(0, 0, 0, 0.1);
    }

    body.dark .nav-links {
        background: rgba(30, 41, 59, 0.95);
        backdrop-filter: blur(12px);
        -webkit-backdrop-filter: blur(12px);
    }

    .nav-links.open {
        display: flex;
    }

    .menu-toggle {
        display: block;
    }

    .banner {
        height: 320px;
    }

    .banner h1 {
        font-size: 2rem;
    }

    .banner p {
        font-size: 1rem;
    }

    .grid-2,
    .grid-3,
    .grid-4 {
        grid-template-columns: 1fr;
    }

    .about-stats {
        flex-wrap: wrap;
        gap: 20px;
    }

    .back-top,
    .dark-mode-toggle {
        bottom: 20px;
        right: 20px;
    }

    .dark-mode-toggle {
        bottom: 80px;
    }

    .section-title h2 {
        font-size: 1.8rem;
    }

    .card {
        padding: 20px;
    }
}

/* 滚动动画 */
.fade-in {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.8s ease, transform 0.8s ease;
}

.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}

/* 图片懒加载占位 */
.lazy-placeholder {
    background: #e2e8f0;
    border-radius: 12px;
    min-height: 120px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: #94a3b8;
    font-size: 0.9rem;
}

body.dark .lazy-placeholder {
    background: #1e293b;
    color: #64748b;
}