/* 基础样式 */
:root {
    --primary-color: #004a99; /* 科技蓝 */
    --secondary-color: #ffffff; /* 纯白 */
    --accent-color: #007bff; /* 亮蓝 */
    --text-dark: #333333;
    --text-light: #666666;
    --bg-gray: #f4f7f9;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: "Helvetica Neue", Helvetica, Arial, "Microsoft Yahei", sans-serif;
    line-height: 1.6;
    color: var(--text-dark);
    background-color: var(--secondary-color);
}

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

a {
    text-decoration: none;
    transition: 0.3s;
}

ul {
    list-style: none;
}

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

/* 导航栏 */
nav {
    background: rgba(255, 255, 255, 0.98);
    height: 80px;
    display: flex;
    align-items: center;
    position: fixed;
    top: 0;
    width: 100%;
    z-index: 1000;
    box-shadow: 0 2px 15px rgba(0,0,0,0.1);
}

nav .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    width: 100%;
}

.logo {
    font-size: 26px;
    font-weight: bold;
    color: var(--primary-color);
    letter-spacing: 1px;
}

.nav-links {
    display: flex;
}

.nav-links > li {
    margin-left: 5px;
    position: relative;
}

.nav-links > li > a {
    color: var(--text-dark);
    font-weight: 500;
    padding: 30px 15px;
    display: block;
    font-size: 16px;
}

.nav-links > li:hover > a {
    color: var(--primary-color);
}

/* 下拉菜单 */
.dropdown-menu {
    position: absolute;
    top: 80px;
    left: 0;
    background: white;
    box-shadow: 0 5px 20px rgba(0,0,0,0.1);
    display: none;
    min-width: 200px;
    border-radius: 0 0 5px 5px;
    border-top: 3px solid var(--primary-color);
    padding: 10px 0;
}

.dropdown:hover .dropdown-menu {
    display: block;
}

.dropdown-menu li {
    width: 100%;
}

.dropdown-menu a {
    padding: 12px 20px;
    display: block;
    color: var(--text-dark);
    font-size: 14px;
    border-bottom: 1px solid #f8f9fa;
}

.dropdown-menu a:hover {
    background: #f0f7ff;
    color: var(--primary-color);
    padding-left: 25px;
}

/* 详情页头部 */
.page-header {
    background: linear-gradient(rgba(0, 74, 153, 0.9), rgba(0, 74, 153, 0.9)), url('img/changfang2.jpg');
    background-size: cover;
    background-position: center;
    color: white;
    padding: 100px 0 60px;
    text-align: center;
}

.page-header h1 {
    font-size: 36px;
    margin-bottom: 15px;
}

/* 第一屏：Hero */
.hero {
    height: 85vh;
    min-height: 500px;
    background: url('img/changfang2.jpg') no-repeat center center/cover;
    position: relative;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    color: var(--secondary-color);
}

.hero .overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.4);
}

.hero-content {
    position: relative;
    z-index: 1;
}

.hero h1 {
    font-size: 56px;
    margin-bottom: 25px;
    letter-spacing: 3px;
    font-weight: 800;
}

.hero .subtitle {
    font-size: 18px;
    margin-bottom: 45px;
    opacity: 0.95;
    letter-spacing: 2px;
}

.hero-btns .btn {
    padding: 15px 40px;
    border-radius: 5px;
    font-size: 18px;
    margin: 0 15px;
    display: inline-block;
    font-weight: bold;
    text-transform: uppercase;
}

.btn-primary {
    background: var(--primary-color);
    color: white;
}

.btn-primary:hover {
    background: var(--accent-color);
    transform: translateY(-3px);
}

.btn-secondary {
    border: 2px solid white;
    color: white;
}

.btn-secondary:hover {
    background: white;
    color: var(--primary-color);
    transform: translateY(-3px);
}

/* 通用标题 */
.section-title {
    text-align: center;
    font-size: 36px;
    margin-bottom: 60px;
    position: relative;
    padding-bottom: 20px;
    color: var(--primary-color);
}

.section-title::after {
    content: '';
    width: 80px;
    height: 4px;
    background: var(--primary-color);
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
}

/* 第二屏：产品展示 */
.products {
    padding: 100px 0;
}

.product-item {
    display: flex;
    align-items: center;
    margin-bottom: 80px;
    gap: 60px;
}

.product-item.reverse {
    flex-direction: row-reverse;
}

.product-img {
    flex: 1;
}

.product-img img {
    border-radius: 15px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.15);
    width: 100%;
    height: 400px;
    object-fit: cover;
}

.product-info {
    flex: 1;
}

.product-info h3 {
    font-size: 32px;
    color: var(--primary-color);
    margin-bottom: 25px;
}

.product-info ul li {
    font-size: 18px;
    margin-bottom: 15px;
    padding-left: 25px;
    position: relative;
}

.product-info ul li::before {
    content: '\f058';
    font-family: 'Font Awesome 6 Free';
    font-weight: 900;
    color: var(--primary-color);
    position: absolute;
    left: 0;
}

/* 第三屏：应用领域 */
.applications {
    background: var(--bg-gray);
    padding: 100px 0;
}

.app-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 40px;
}

.app-card {
    background: white;
    padding: 50px 30px;
    text-align: center;
    border-radius: 15px;
    transition: 0.4s;
    box-shadow: 0 5px 20px rgba(0,0,0,0.05);
}

.app-card:hover {
    transform: translateY(-15px);
    box-shadow: 0 15px 35px rgba(0,0,0,0.1);
}

.app-card i {
    font-size: 50px;
    color: var(--primary-color);
    margin-bottom: 25px;
}

.app-card h4 {
    font-size: 22px;
    margin-bottom: 15px;
}

/* 第四屏：生产实力 */
.factory {
    padding: 100px 0;
}

.factory-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
    margin-bottom: 50px;
}

.factory-item {
    text-align: center;
}

.factory-item img {
    height: 300px;
    width: 100%;
    object-fit: cover;
    border-radius: 10px;
    margin-bottom: 15px;
}

.factory-item p {
    font-weight: bold;
    font-size: 18px;
    color: var(--text-dark);
}

.factory-highlights {
    display: flex;
    justify-content: center;
    gap: 60px;
    flex-wrap: wrap;
    background: var(--primary-color);
    color: white;
    padding: 40px;
    border-radius: 15px;
    margin-top: 20px;
}

.highlight-item {
    font-size: 24px;
    font-weight: bold;
}

/* 第五屏：常见问题 */
.tech-guarantee {
    background: white;
    color: #333;
    padding: 100px 0;
    text-align: center;
}

.tech-guarantee .section-title {
    color: #333;
}

.tech-guarantee .section-title::after {
    background: var(--primary-color);
}

.faq-grid {
    display: grid;
    grid-template-columns: 1fr 1fr 2fr;
    gap: 30px;
    margin-top: 40px;
    text-align: left;
}

.report-card {
    text-align: center;
    cursor: pointer;
}

.report-card img {
    width: 100%;
    max-width: 250px;
    border: 1px solid #eee;
    box-shadow: 0 5px 15px rgba(0,0,0,0.1);
    transition: transform 0.3s;
    margin-bottom: 15px;
}

.report-card:hover img {
    transform: translateY(-5px);
}

.report-card p {
    font-size: 18px;
    font-weight: bold;
    color: #333;
}

.faq-preview-list ul {
    list-style: none;
    padding: 0;
}

.faq-preview-list li {
    margin-bottom: 12px;
    border-bottom: 1px dashed #eee;
    padding-bottom: 8px;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.faq-preview-list a {
    color: #333;
    text-decoration: none;
    transition: color 0.3s;
    font-size: 16px;
}

.faq-preview-list a:hover {
    color: var(--primary-color);
}

@media (max-width: 768px) {
    .faq-grid {
        grid-template-columns: 1fr;
    }
}

.tech-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 30px;
    margin-top: 40px;
}

.tech-card {
    padding: 30px;
}

.tech-card i {
    font-size: 40px;
    color: #00d1ff;
    margin-bottom: 20px;
}

.tech-card p {
    font-size: 20px;
    font-weight: 500;
}

/* 第六屏：SEO 文字 */
.seo-section {
    padding: 80px 0;
    background: #fdfdfd;
    border-top: 1px solid #eee;
}

.seo-content {
    line-height: 2;
    color: #777;
    font-size: 15px;
    text-align: justify;
}

.seo-content strong {
    color: var(--primary-color);
}

.seo-contact-info {
    margin-top: 30px;
    padding: 25px;
    background: #f0f7ff;
    border-left: 5px solid var(--primary-color);
    color: var(--text-dark);
}

/* 详情页文章内容 */
.content-section {
    padding: 80px 0;
}

/* 产品详情样式 */
.product-detail {
    margin-bottom: 100px;
    padding-top: 50px; /* 留出导航栏空间 */
}

.detail-grid {
    display: flex;
    align-items: center;
    gap: 60px;
    margin-top: 40px;
}

.detail-grid.reverse {
    flex-direction: row-reverse;
}

.detail-img {
    flex: 1;
}

.detail-img img {
    border-radius: 15px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.1);
    width: 100%;
}

.detail-text {
    flex: 1.2;
}

.detail-text h3 {
    font-size: 28px;
    color: var(--primary-color);
    margin-bottom: 20px;
}

.detail-text p {
    margin-bottom: 20px;
    color: #555;
}

.detail-text ul {
    margin-bottom: 20px;
}

.detail-text ul li {
    margin-bottom: 10px;
    padding-left: 25px;
    position: relative;
}

.detail-text ul li::before {
    content: '\f058';
    font-family: 'Font Awesome 6 Free';
    font-weight: 900;
    color: var(--primary-color);
    position: absolute;
    left: 0;
}

hr {
    border: none;
    border-top: 1px solid #eee;
    margin: 80px 0;
}

/* 应用领域详情 */
.app-detail {
    padding-top: 50px;
    margin-bottom: 60px;
}

.app-content p {
    margin-bottom: 20px;
    color: #555;
    text-indent: 2em;
}

/* 技术支持样式 */
.tech-detail {
    padding-top: 50px;
    margin-bottom: 80px;
}

.tech-table-wrapper {
    overflow-x: auto;
    margin: 30px 0;
}

.tech-table {
    width: 100%;
    border-collapse: collapse;
    min-width: 600px;
}

.tech-table th, .tech-table td {
    padding: 15px;
    border: 1px solid #ddd;
    text-align: left;
}

.tech-table th {
    background: var(--primary-color);
    color: white;
}

.tech-table tr:nth-child(even) {
    background: #f9f9f9;
}

.usage-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
    margin-top: 30px;
}

.usage-item {
    background: #f8f9fa;
    padding: 30px;
    border-radius: 10px;
    border-top: 4px solid var(--primary-color);
}

.usage-item h4 {
    margin-bottom: 15px;
    color: var(--primary-color);
}

.storage-list li {
    margin-bottom: 15px;
    padding-left: 30px;
    position: relative;
}

.storage-list li::before {
    content: '\f0d1';
    font-family: 'Font Awesome 6 Free';
    font-weight: 900;
    color: var(--primary-color);
    position: absolute;
    left: 0;
}

/* FAQ 样式 */
.faq-list {
    max-width: 900px;
    margin: 0 auto;
}

.faq-item {
    background: white;
    margin-bottom: 20px;
    padding: 30px;
    border-radius: 10px;
    box-shadow: 0 5px 15px rgba(0,0,0,0.05);
}

.faq-item h3 {
    color: var(--primary-color);
    margin-bottom: 15px;
    font-size: 20px;
}

.faq-answer p {
    margin-bottom: 10px;
    color: #666;
}

/* 关于我们样式 */
.about-text-main {
    margin-bottom: 60px;
}

.about-text-main p {
    text-indent: 2em;
    margin-bottom: 20px;
}

.culture-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
    margin: 60px 0;
}

.culture-card {
    text-align: center;
    padding: 40px 20px;
    background: var(--bg-gray);
    border-radius: 15px;
}

.culture-card i {
    font-size: 40px;
    color: var(--primary-color);
    margin-bottom: 20px;
}

.contact-section-page {
    padding-top: 50px;
    margin-top: 80px;
}

.contact-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 50px;
    margin-top: 30px;
}

.contact-item {
    margin-bottom: 20px;
    font-size: 18px;
}

.contact-item i {
    color: var(--primary-color);
    margin-right: 15px;
}

/* SEO 延伸文字通用样式 */
.seo-extended-content {
    margin-top: 100px;
    padding: 60px;
    background: #f9f9f9;
    border-radius: 20px;
    line-height: 2;
    color: #555;
}

.seo-extended-content p {
    margin-bottom: 25px;
    text-indent: 2em;
}

/* 生产实景页样式 */
.factory-gallery {
    margin: 60px 0;
}

.gallery-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
}

.gallery-item {
    background: white;
    border-radius: 15px;
    overflow: hidden;
    box-shadow: 0 10px 30px rgba(0,0,0,0.08);
    transition: 0.3s;
}

.gallery-item:hover {
    transform: translateY(-10px);
}

.gallery-item img {
    width: 100%;
    height: 250px;
    object-fit: cover;
}

.gallery-desc {
    padding: 25px;
}

.gallery-desc h4 {
    color: var(--primary-color);
    margin-bottom: 10px;
    font-size: 20px;
}

.gallery-desc p {
    font-size: 14px;
    color: #777;
}

.factory-stats {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 30px;
    background: var(--primary-color);
    padding: 60px 40px;
    border-radius: 20px;
    color: white;
    text-align: center;
    margin-bottom: 80px;
}

.stat-number {
    display: block;
    font-size: 42px;
    font-weight: 800;
    margin-bottom: 10px;
}

.stat-label {
    font-size: 16px;
    opacity: 0.9;
}

/* 联系我们页样式 */
.contact-grid-page {
    display: grid;
    grid-template-columns: 1fr 1.2fr;
    gap: 60px;
    margin-bottom: 80px;
}

.contact-info-card {
    background: var(--bg-gray);
    padding: 50px;
    border-radius: 20px;
}

.contact-details .contact-item {
    display: flex;
    align-items: flex-start;
    margin-bottom: 35px;
}

.contact-details .contact-item i {
    font-size: 24px;
    color: var(--primary-color);
    background: white;
    width: 50px;
    height: 50px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    margin-right: 20px;
    box-shadow: 0 5px 15px rgba(0,0,0,0.05);
}

.contact-details h4 {
    margin-bottom: 5px;
    color: var(--text-dark);
}

.contact-brand-story {
    padding: 20px 0;
}

.contact-brand-story p {
    margin-bottom: 25px;
    line-height: 2;
    color: #555;
    text-indent: 2em;
}

/* 响应式调整 */
@media (max-width: 992px) {
    .contact-grid-page {
        grid-template-columns: 1fr;
    }
    .factory-stats {
        grid-template-columns: 1fr 1fr;
    }
}

@media (max-width: 576px) {
    .factory-stats {
        grid-template-columns: 1fr;
    }
}

/* 页脚 */
footer {
    background: #1a1a1a;
    color: #bbb;
    padding: 80px 0 30px;
}

.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1.5fr;
    gap: 60px;
    margin-bottom: 50px;
}

.footer-info h3, .footer-links h4, .footer-contact h4 {
    color: white;
    margin-bottom: 25px;
    font-size: 20px;
}

.footer-links ul li {
    margin-bottom: 12px;
}

.footer-links a {
    color: #bbb;
}

.footer-links a:hover {
    color: white;
    padding-left: 5px;
}

.footer-bottom {
    border-top: 1px solid #333;
    padding-top: 30px;
    text-align: center;
    font-size: 14px;
}

/* 响应式设计 */
@media (max-width: 992px) {
    .product-item, .product-item.reverse {
        flex-direction: column;
        gap: 30px;
    }
    .footer-grid {
        grid-template-columns: 1fr 1fr;
    }
}

@media (max-width: 768px) {
    nav {
        height: 70px;
    }
    .nav-links {
        display: none; /* 移动端暂时隐藏，可根据需求加汉堡菜单 */
    }
    .hero h1 {
        font-size: 36px;
    }
    .hero .subtitle {
        font-size: 18px;
        letter-spacing: 2px;
    }
    .factory-grid {
        grid-template-columns: 1fr;
    }
    .footer-grid {
        grid-template-columns: 1fr;
    }
    .highlight-item {
        font-size: 18px;
    }
}