/* 占位图片 - img加载失败时显示（不影响正常图片） */
img {
    position: relative;
}
img::before {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: #f0f0f0 url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='200' height='150' viewBox='0 0 200 150'%3E%3Crect fill='%23f0f0f0' width='200' height='150'/%3E%3Ctext x='100' y='80' text-anchor='middle' fill='%23999' font-size='14' font-family='sans-serif'%3E图片占位%3C/text%3E%3C/svg%3E") no-repeat center/cover;
    z-index: 1;
}
img[src]::before {
    display: none;
}

/* 头部区域 */
.header {
    position: sticky;
    top: 0;
    z-index: 1000;
    background: #fff;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}

.header-top {
    padding: 15px 0;
    background: #fff;
}

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

.logo img {
    max-width: 200px;
    height: 50px;
    object-fit: contain;
    background: none;
}
.logotext {
    margin-left: -200px;
    font-size: 26px;
}
.header-contact {
    display: flex;
    align-items: center;
    gap: 30px;
}

.header-contact .hotline {
    font-size: 16px;
    color: #666;
}

.header-contact .hotline strong {
    color: #d42121;
    font-size: 24px;
    font-weight: 700;
}

.header-contact .address {
    color: #999;
    font-size: 14px;
}

/* 主导航 */
.main-nav {
    background: #d42121;
    position: relative;
}

.main-nav .container {
    position: relative;
    display: flex;
    align-items: center;
}

.nav-list {
    display: flex;
    align-items: center;
    height: 50px;
}

.nav-list > li {
    position: relative;
}

.nav-list > li > a {
    display: block;
    padding: 0 30px;
    color: #fff;
    font-size: 16px;
    line-height: 50px;
    transition: background 0.3s ease;
}

.nav-list > li > a:hover,
.nav-list > li.active > a {
    background: rgba(0,0,0,0.2);
    color: #fff;
}

/* 下拉菜单 */
.dropdown-menu {
    position: absolute;
    top: 100%;
    left: 0;
    min-width: 200px;
    background: #fff;
    box-shadow: 0 5px 15px rgba(0,0,0,0.1);
    opacity: 0;
    visibility: hidden;
    transform: translateY(10px);
    transition: all 0.3s ease;
    z-index: 100;
}

.dropdown:hover .dropdown-menu {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.dropdown-menu li a {
    display: block;
    padding: 12px 20px;
    color: #333;
    font-size: 14px;
    border-bottom: 1px solid #eee;
    transition: all 0.3s ease;
}

.dropdown-menu li a:hover {
    background: #f5f5f5;
    color: #d42121;
    padding-left: 25px;
}

/* 移动端菜单按钮 */
.mobile-menu-btn {
    display: none;
    width: 30px;
    height: 25px;
    cursor: pointer;
    position: absolute;
    right: 15px;
    top: 50%;
    transform: translateY(-50%);
}

.mobile-menu-btn .icon-bar {
    display: block;
    width: 100%;
    height: 3px;
    background: #fff;
    border-radius: 2px;
    margin-bottom: 5px;
    transition: all 0.3s ease;
}

.mobile-menu-btn.active .icon-bar:nth-child(1) {
    transform: rotate(45deg) translate(5px, 5px);
}

.mobile-menu-btn.active .icon-bar:nth-child(2) {
    opacity: 0;
}

.mobile-menu-btn.active .icon-bar:nth-child(3) {
    transform: rotate(-45deg) translate(5px, -5px);
}

.mobile-nav-overlay {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0,0,0,0.5);
    z-index: 998;
    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: 100%;
    background: #fff;
    z-index: 999;
    transition: right 0.3s ease;
    overflow-y: auto;
}

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

.mobile-nav-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 15px 20px;
    background: #d42121;
    color: #fff;
    font-size: 18px;
}

.mobile-nav-close {
    font-size: 28px;
    color: #fff;
    cursor: pointer;
    background: none;
    border: none;
}

.mobile-nav-list {
    padding: 10px 0;
}

.mobile-nav-list li a {
    display: block;
    padding: 15px 20px;
    color: #333;
    font-size: 16px;
    border-bottom: 1px solid #eee;
    transition: all 0.3s ease;
}

.mobile-nav-list li a:hover,
.mobile-nav-list li.active a {
    background: #f5f5f5;
    color: #d42121;
}

/* ========== Banner样式 ========== */
.banner {
    position: relative;
    overflow: hidden;
}

.banner-slider {
    position: relative;
    min-height: 200px;
}

.slide {
    display: none;
    position: relative;
}

.slide.active {
    display: block;
}

.slide img {
    width: 100%;
    height: 500px;
    object-fit: cover;
    display: block;
}

.slide-content {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    display: flex;
    align-items: center;
    background: rgba(0,0,0,0.4);
    color: #fff;
}

.slide-content h2 {
    font-size: 48px;
    font-weight: 700;
    margin-bottom: 20px;
    animation: fadeInUp 0.8s ease;
}

.slide-content p {
    font-size: 24px;
    margin-bottom: 30px;
    animation: fadeInUp 1s ease;
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* ========== 按钮样式 ========== */
.btn {
    display: inline-block;
    padding: 12px 35px;
    border-radius: 4px;
    font-size: 16px;
    text-align: center;
    transition: all 0.3s ease;
    cursor: pointer;
    text-decoration: none;
}

.btn-primary {
    background: #d42121;
    color: #fff;
}

.btn-primary:hover {
    background: #b81a1a;
    color: #fff;
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(212,33,33,0.3);
}

.btn-secondary {
    background: #fff;
    color: #d42121;
    border: 2px solid #d42121;
}

.btn-secondary:hover {
    background: #d42121;
    color: #fff;
}

/* ========== 搜索区域 ========== */
.search-section {
    background: #f5f5f5;
    padding: 15px 0;
}

.search-section .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 10px;
}

.hot-keys {
    font-size: 14px;
    color: #666;
}

.hot-keys a {
    display: inline-block;
    margin-left: 15px;
    color: #666;
    transition: color 0.3s ease;
}

.hot-keys a:hover {
    color: #d42121;
}

.search-form {
    display: flex;
}

.search-form input {
    width: 250px;
    padding: 8px 15px;
    border: 1px solid #ddd;
    border-right: none;
    border-radius: 4px 0 0 4px;
    font-size: 14px;
}

.search-form button {
    padding: 8px 20px;
    background: #d42121;
    color: #fff;
    border: none;
    border-radius: 0 4px 4px 0;
    cursor: pointer;
    transition: background 0.3s ease;
}

.search-form button:hover {
    background: #b81a1a;
}

/* ========== 通用区块标题 ========== */
.section-header {
    text-align: center;
    margin-bottom: 50px;
}

.section-header h2 {
    font-size: 36px;
    color: #333;
    font-weight: 700;
    margin-bottom: 10px;
}

.section-header p {
    font-size: 16px;
    color: #999;
    letter-spacing: 2px;
}

.section-header .more-link {
    display: inline-block;
    margin-top: 15px;
    color: #d42121;
    font-size: 14px;
}

/* ========== 产品中心 ========== */
.products-section {
    padding: 80px 0;
    background: #fff;
}

.product-categories {
    display: grid;
    grid-template-columns: repeat(5, 1fr);
    gap: 20px;
    margin-bottom: 50px;
}

.category-item {
    text-align: center;
    padding: 30px 20px;
    background: #f9f9f9;
    border-radius: 8px;
    transition: all 0.3s ease;
    text-decoration: none;
    color: inherit;
}

.category-item:hover {
    background: #d42121;
    color: #fff;
    transform: translateY(-5px);
    box-shadow: 0 10px 30px rgba(212,33,33,0.2);
}

.category-item:hover h3 {
    color: #fff;
}

.category-icon {
    width: 60px;
    height: 60px;
    margin: 0 auto 15px;
}

.category-icon img {
    width: 100%;
    height: 100%;
    object-fit: contain;
    background: none;
}

.category-item h3 {
    font-size: 16px;
    color: #333;
    transition: color 0.3s ease;
}

.product-showcase {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 25px;
}

.product-card {
    background: #fff;
    border-radius: 8px;
    overflow: hidden;
    box-shadow: 0 5px 20px rgba(0,0,0,0.08);
    transition: all 0.3s ease;
}

.product-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 40px rgba(0,0,0,0.15);
}

.product-image {
    position: relative;
    overflow: hidden;
}

.product-image img {
    width: 100%;
    height: 200px;
    object-fit: cover;
    transition: transform 0.5s ease;
    display: block;
}

.product-card:hover .product-image img {
    transform: scale(1.1);
}

.product-info {
    padding: 20px;
}

.product-info h3 {
    font-size: 18px;
    margin-bottom: 10px;
}

.product-info h3 a {
    color: #333;
    text-decoration: none;
}

.product-info h3 a:hover {
    color: #d42121;
}

.product-info p {
    color: #666;
    font-size: 14px;
    margin-bottom: 10px;
}

.product-tag {
    display: inline-block;
    padding: 4px 12px;
    background: #d42121;
    color: #fff;
    font-size: 12px;
    border-radius: 20px;
}

/* ========== 关于我们 ========== */
.about-section {
    padding: 80px 0;
    background: #f9f9f9;
}

.about-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 50px;
    align-items: center;
}

.about-text h2 {
    font-size: 36px;
    color: #333;
    margin-bottom: 10px;
}

.about-text h3 {
    font-size: 16px;
    color: #999;
    letter-spacing: 2px;
    margin-bottom: 20px;
}

.about-desc p {
    color: #666;
    line-height: 1.8;
    margin-bottom: 15px;
}

.about-image img {
    width: 100%;
    height: 400px;
    object-fit: cover;
    border-radius: 8px;
    display: block;
}

/* ========== 公司优势 ========== */
.advantages-section {
    padding: 80px 0;
    background: #d42121;
    color: #fff;
}

.advantages-section .section-header h2 {
    color: #fff;
}

.advantages-section .section-header p {
    color: rgba(255,255,255,0.7);
}

.advantages-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 30px;
}

.advantage-item {
    text-align: center;
    padding: 40px 20px;
    background: rgba(255,255,255,0.1);
    border-radius: 8px;
    transition: all 0.3s ease;
}

.advantage-item:hover {
    background: rgba(255,255,255,0.2);
    transform: translateY(-5px);
}

.adv-icon {
    font-size: 48px;
    font-weight: 700;
    margin-bottom: 20px;
    color: #fff;
}

.advantage-item h3 {
    font-size: 20px;
    margin-bottom: 15px;
    color: #fff;
}

.advantage-item p {
    color: rgba(255,255,255,0.8);
    font-size: 14px;
    line-height: 1.6;
}

/* ========== 新闻动态 ========== */
.news-section {
    padding: 80px 0;
    background: #fff;
}

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

.news-card {
    background: #fff;
    border-radius: 8px;
    overflow: hidden;
    box-shadow: 0 5px 20px rgba(0,0,0,0.08);
    transition: all 0.3s ease;
}

.news-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 40px rgba(0,0,0,0.15);
}

.news-image {
    position: relative;
    overflow: hidden;
}

.news-image img {
    width: 100%;
    height: 200px;
    object-fit: cover;
    transition: transform 0.5s ease;
    display: block;
}

.news-card:hover .news-image img {
    transform: scale(1.1);
}

.news-date {
    position: absolute;
    top: 15px;
    left: 15px;
    padding: 8px 15px;
    background: #d42121;
    color: #fff;
    font-size: 12px;
    border-radius: 4px;
}

.news-content {
    padding: 20px;
}

.news-content h3 {
    font-size: 18px;
    margin-bottom: 10px;
}

.news-content h3 a {
    color: #333;
    text-decoration: none;
}

.news-content h3 a:hover {
    color: #d42121;
}

.news-content p {
    color: #666;
    font-size: 14px;
    line-height: 1.6;
}

/* ========== 客户案例 ========== */
.cases-section {
    padding: 80px 0;
    background: #f9f9f9;
}

.cases-slider {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
}

.case-card {
    position: relative;
    border-radius: 8px;
    overflow: hidden;
    box-shadow: 0 5px 20px rgba(0,0,0,0.08);
}

.case-card img {
    width: 100%;
    height: 250px;
    object-fit: cover;
    display: block;
}

.case-info {
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    padding: 20px;
    background: linear-gradient(transparent, rgba(0,0,0,0.8));
    color: #fff;
}

.case-info h3 {
    font-size: 18px;
    margin-bottom: 5px;
}

.case-info p {
    font-size: 14px;
    color: rgba(255,255,255,0.8);
    margin: 0;
}

/* ========== CTA区域 ========== */
.cta-section {
    padding: 80px 0;
    background: linear-gradient(135deg, #d42121 0%, #b81a1a 100%);
    color: #fff;
    text-align: center;
}

.cta-section h2 {
    font-size: 36px;
    margin-bottom: 15px;
}

.cta-section p {
    font-size: 18px;
    margin-bottom: 30px;
    color: rgba(255,255,255,0.9);
}

.cta-section .btn-secondary {
    background: #fff;
    color: #d42121;
    border-color: #fff;
}

.cta-section .btn-secondary:hover {
    background: transparent;
    color: #fff;
}

.cta-phone {
    display: block;
    margin-top: 20px;
    font-size: 16px;
    color: rgba(255,255,255,0.9);
}

.cta-phone strong {
    font-size: 24px;
    color: #fff;
}

/* ========== 页脚 ========== */
.footer {
    background: #222;
    color: #ccc;
    padding-top: 60px;
}

.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1.5fr;
    gap: 40px;
    padding-bottom: 40px;
    border-bottom: 1px solid #333;
}

.footer-logo {
    margin-bottom: 20px;
}

.footer-logo img {
    max-width: 150px;
    background: none;
}

.footer-about p {
    color: #999;
    font-size: 14px;
    line-height: 1.8;
    margin-bottom: 20px;
}

.footer-social {
    display: flex;
    gap: 15px;
}

.footer-social a {
    display: inline-block;
    padding: 8px 15px;
    background: #333;
    color: #ccc;
    font-size: 12px;
    border-radius: 4px;
    transition: all 0.3s ease;
    text-decoration: none;
}

.footer-social a:hover {
    background: #d42121;
    color: #fff;
}

.footer-col h3 {
    font-size: 18px;
    color: #fff;
    margin-bottom: 20px;
}

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

.footer-links li a {
    color: #999;
    font-size: 14px;
    transition: color 0.3s ease;
    text-decoration: none;
}

.footer-links li a:hover {
    color: #d42121;
}

.contact-info li {
    display: flex;
    align-items: flex-start;
    margin-bottom: 15px;
    color: #999;
    font-size: 14px;
}

.contact-info .icon {
    margin-right: 10px;
    font-size: 16px;
}

.contact-info strong {
    color: #d42121;
    font-size: 18px;
}

/* ========== 版权区域 ========== */
.footer-bottom {
    padding: 20px 0;
    background: #1a1a1a;
}

.copyright {
    display: flex;
    align-items: center;
    justify-content: space-between;
    font-size: 14px;
    color: #666;
}

.copyright a {
    color: #666;
    text-decoration: none;
}

.copyright a:hover {
    color: #d42121;
}

.copyright .sep {
    margin: 0 10px;
    color: #444;
}

/* ========== 回到顶部 ========== */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    background: #d42121;
    color: #fff;
    border: none;
    border-radius: 50%;
    font-size: 20px;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s ease;
    z-index: 999;
}

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

.back-to-top:hover {
    background: #b81a1a;
    transform: translateY(-3px);
}