/* ===== 全局变量 ===== */
:root {
    --primary-color: #0a5cf5;
    --secondary-color: #061738;
    --accent-color: #f05a5a;
    --gradient-blue: linear-gradient(145deg, #0a5cf5 0%, #0a3c9c 100%);
    --gradient-dark: linear-gradient(145deg, #061738 0%, #0a1a38 100%);
    --text-dark: #2c3e50;
    --text-light: #6c757d;
    --text-white: #ffffff;
    --border-color: #e9ecef;
    --bg-light: #f8faff;
    --bg-dark: #0b1c3a;
    --shadow-sm: 0 5px 20px rgba(0,0,0,0.05);
    --shadow-md: 0 10px 30px rgba(0,0,0,0.08);
    --shadow-lg: 0 20px 45px rgba(0,0,0,0.1);
    --shadow-blue: 0 10px 30px rgba(10,92,245,0.15);
    --transition: all 0.3s ease;
}

/* ===== 重置样式 ===== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Inter', 'Segoe UI', 'Microsoft YaHei', sans-serif;
    color: var(--text-dark);
    line-height: 1.6;
    background: var(--bg-light);
    overflow-x: hidden;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 15px;
}

/* ===== 顶部栏 ===== */
.top-bar {
    background: var(--secondary-color);
    color: var(--text-white);
    padding: 10px 0;
    font-size: 14px;
    border-bottom: 1px solid rgba(255,255,255,0.1);
}

.top-bar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 15px;
}

.contact-info {
    display: flex;
    flex-wrap: wrap;
    gap: 25px;
}

.contact-info span {
    display: flex;
    align-items: center;
    gap: 8px;
    color: #a0b3d9;
}

.contact-info i {
    color: var(--primary-color);
    width: 18px;
}

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

.social-links a {
    color: #a0b3d9;
    transition: var(--transition);
}

.social-links a:hover {
    color: var(--primary-color);
    transform: translateY(-2px);
}

/* ===== 主头部 ===== */
.main-header {
    background: var(--text-white);
    box-shadow: var(--shadow-sm);
    position: sticky;
    top: 0;
    z-index: 1000;
    transition: var(--transition);
}

.main-header.scrolled {
    box-shadow: var(--shadow-md);
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 90px;
}

/* Logo */
.logo {
    display: flex;
    align-items: center;
    gap: 15px;
}

.logo img {
    height: 50px;
    width: auto;
}

.logo-text h1 {
    font-size: 24px;
    color: var(--secondary-color);
    font-weight: 700;
    line-height: 1.2;
}

.logo-text p {
    font-size: 12px;
    color: var(--primary-color);
    letter-spacing: 1px;
    text-transform: uppercase;
}

/* ===== 面包屑导航 ===== */
.breadcrumb-section {
    background: var(--bg-light);
    padding: 30px 0;
    border-bottom: 1px solid var(--border-color);
}

.breadcrumb {
    margin: 0;
    padding: 0;
    background: transparent;
}

.breadcrumb a {
    color: var(--text-light);
    text-decoration: none;
    transition: var(--transition);
}

.breadcrumb a:hover {
    color: var(--primary-color);
}

.breadcrumb span {
    color: var(--primary-color);
    font-weight: 600;
}

.separator {
    margin: 0 15px;
    color: var(--border-color);
}

/* ===== 标题样式 ===== */
.section-header {
    text-align: center;
    margin-bottom: 60px;
}

.section-subtitle {
    font-size: 16px;
    text-transform: uppercase;
    letter-spacing: 3px;
    color: var(--primary-color);
    margin-bottom: 15px;
    font-weight: 600;
}

.section-title {
    font-size: 42px;
    font-weight: 700;
    color: var(--secondary-color);
    line-height: 1.3;
    margin-bottom: 20px;
    position: relative;
}

.section-title span {
    color: var(--primary-color);
}

.section-desc {
    font-size: 16px;
    color: var(--text-light);
    max-width: 700px;
    margin: 0 auto;
}

/* ===== 页脚 ===== */
.footer {
    background: var(--secondary-color);
    color: var(--text-white);
    padding: 80px 0 30px;
}

.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1.5fr;
    gap: 40px;
    margin-bottom: 60px;
}

.footer-about p {
    color: #a0b3d9;
    line-height: 1.8;
    margin: 20px 0;
}

.footer h3 {
    color: white;
    font-size: 18px;
    margin-bottom: 25px;
    position: relative;
    padding-bottom: 15px;
}

.footer h3:after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 50px;
    height: 2px;
    background: var(--primary-color);
}

.footer ul {
    list-style: none;
}

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

.footer ul li a {
    color: #a0b3d9;
    text-decoration: none;
    transition: var(--transition);
    display: inline-flex;
    align-items: center;
    gap: 8px;
}

.footer ul li a:hover {
    color: var(--primary-color);
    padding-left: 5px;
}

.footer ul li i {
    color: var(--primary-color);
    font-size: 12px;
}

.footer-contact li {
    display: flex;
    align-items: center;
    gap: 12px;
    color: #a0b3d9;
    margin-bottom: 15px;
}

.footer-contact li i {
    width: 20px;
    color: var(--primary-color);
}

.social-links-footer {
    display: flex;
    gap: 15px;
    margin-top: 25px;
}

.social-links-footer a {
    width: 45px;
    height: 45px;
    background: rgba(255,255,255,0.1);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    transition: var(--transition);
}

.social-links-footer a:hover {
    background: var(--primary-color);
    transform: translateY(-3px);
}

.copyright {
    border-top: 1px solid rgba(255,255,255,0.1);
    padding-top: 30px;
    text-align: center;
    color: #a0b3d9;
}

.copyright a {
    color: #a0b3d9;
    text-decoration: none;
    transition: var(--transition);
    margin: 0 10px;
}

.copyright a:hover {
    color: var(--primary-color);
}

/* ===== 返回顶部 ===== */
.back-to-top {
    position: fixed;
    bottom: 40px;
    right: 40px;
    width: 55px;
    height: 55px;
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: 50%;
    cursor: pointer;
    display: none;
    align-items: center;
    justify-content: center;
    font-size: 22px;
    box-shadow: var(--shadow-blue);
    transition: var(--transition);
    z-index: 99;
}

.back-to-top:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 35px rgba(10,92,245,0.4);
}

.back-to-top.show {
    display: flex;
    animation: fadeIn 0.3s ease;
}

@keyframes fadeIn {
    from { opacity: 0; transform: scale(0.8); }
    to { opacity: 1; transform: scale(1); }
}

/* ===== 响应式设计 ===== */
@media (max-width: 1200px) {
    .slider-content h2 {
        font-size: 48px;
    }
    .features-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    .products-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 992px) {
    .header-content {
        flex-wrap: wrap;
        height: auto;
        padding: 15px 0;
    }
    .logo {
        width: 100%;
        justify-content: center;
        margin-bottom: 15px;
    }
    .main-nav {
        margin: 15px 0;
        width: 100%;
    }
    .nav-menu {
        flex-wrap: wrap;
        justify-content: center;
    }
    .lang-switcher {
        margin: 10px auto 0;
    }
    .slider-content h2 {
        font-size: 42px;
    }
    .news-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    .footer-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    .hero-slider {
        height: 600px;
    }
    .news-list-item {
        flex-direction: column;
    }
    .news-list-image {
        width: 100%;
        height: 250px;
    }
    .products-layout {
        flex-direction: column;
    }
    .products-sidebar {
        width: 100%;
    }
    .product-gallery-section {
        flex-direction: column-reverse;
    }
    .product-thumbnails {
        width: 100%;
        flex-direction: row;
        overflow-x: auto;
        padding-bottom: 10px;
    }
    .thumbnail-item {
        flex-shrink: 0;
    }
    .key-params-grid {
        grid-template-columns: 1fr;
    }
    .product-detail-layout {
        flex-direction: column;
    }
    .news-layout {
        flex-direction: column;
    }
    .news-sidebar {
        width: 100%;
    }
}

@media (max-width: 768px) {
    .slider-content h2 {
        font-size: 32px;
    }
    .slider-content p {
        font-size: 16px;
    }
    .slider-buttons {
        flex-direction: column;
        gap: 15px;
        align-items: center;
    }
    .btn-primary, .btn-secondary {
        width: 200px;
        text-align: center;
    }
    .slider-arrow {
        width: 45px;
        height: 45px;
        font-size: 18px;
    }
    .slider-arrow.prev {
        left: 15px;
    }
    .slider-arrow.next {
        right: 15px;
    }
    .features-grid {
        grid-template-columns: 1fr;
    }
    .news-grid {
        grid-template-columns: 1fr;
    }
    .footer-grid {
        grid-template-columns: 1fr;
    }
    .section-title {
        font-size: 32px;
    }
    .article-title {
        font-size: 28px;
    }
    .article-meta {
        flex-direction: column;
        gap: 10px;
    }
    .article-navigation {
        flex-direction: column;
        gap: 20px;
    }
    .nav-prev, .nav-next {
        max-width: 100%;
    }
    .nav-next {
        text-align: right;
    }
    .products-grid {
        grid-template-columns: 1fr;
    }
    .params-table td {
        display: block;
        width: 100%;
        padding: 10px;
    }
    .params-table td:first-child {
        background: none;
        font-weight: 600;
        padding-bottom: 0;
    }
    .product-actions {
        flex-direction: column;
    }
}

@media (max-width: 480px) {
    .top-bar .container {
        flex-direction: column;
        text-align: center;
    }
    .contact-info {
        justify-content: center;
    }
    .slider-content h2 {
        font-size: 26px;
    }
    .section-title {
        font-size: 26px;
    }
}