/* ============================================
   公司网站样式表 - 轻量响应式，无外部依赖
   ============================================ */

/* ---------- CSS变量 ---------- */
:root {
    --primary: #0f4c81;
    --primary-light: #1a6bb5;
    --primary-dark: #0a3560;
    --accent: #e8a33d;
    --text: #333;
    --text-light: #666;
    --text-muted: #999;
    --bg: #fff;
    --bg-gray: #f7f9fc;
    --bg-dark: #1a2332;
    --border: #e5e9f0;
    --shadow: 0 2px 12px rgba(0,0,0,0.08);
    --shadow-hover: 0 8px 24px rgba(0,0,0,0.12);
    --radius: 8px;
    --transition: all 0.3s ease;
    --max-width: 1200px;
}

/* ---------- 重置 ---------- */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
                 "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
    font-size: 16px;
    line-height: 1.7;
    color: var(--text);
    background: var(--bg);
    overflow-x: hidden;
}
img { max-width: 100%; height: auto; display: block; }
a { color: var(--primary); text-decoration: none; transition: var(--transition); }
a:hover { color: var(--accent); }
ul { list-style: none; }
button { cursor: pointer; border: none; background: none; font-family: inherit; }
input, textarea, select { font-family: inherit; font-size: inherit; }

/* ---------- 通用容器 ---------- */
.container { max-width: var(--max-width); margin: 0 auto; padding: 0 20px; }
.section { padding: 70px 0; }
.section-gray { background: var(--bg-gray); }
.section-title {
    text-align: center;
    margin-bottom: 50px;
}
.section-title h2 {
    font-size: 32px;
    font-weight: 700;
    color: var(--text);
    margin-bottom: 12px;
    position: relative;
    display: inline-block;
}
.section-title h2::after {
    content: '';
    display: block;
    width: 50px;
    height: 3px;
    background: var(--accent);
    margin: 12px auto 0;
    border-radius: 2px;
}
.section-title p {
    color: var(--text-light);
    font-size: 16px;
    max-width: 600px;
    margin: 0 auto;
}

/* ---------- 按钮 ---------- */
.btn {
    display: inline-block;
    padding: 12px 32px;
    border-radius: var(--radius);
    font-size: 15px;
    font-weight: 500;
    text-align: center;
    transition: var(--transition);
    cursor: pointer;
    border: 2px solid transparent;
}
.btn-primary { background: var(--primary); color: #fff; }
.btn-primary:hover { background: var(--primary-light); color: #fff; transform: translateY(-2px); box-shadow: var(--shadow-hover); }
.btn-outline { background: transparent; color: #fff; border-color: #fff; }
.btn-outline:hover { background: #fff; color: var(--primary); }
.btn-accent { background: var(--accent); color: #fff; }
.btn-accent:hover { background: #d4922e; color: #fff; transform: translateY(-2px); }

/* ---------- 顶部信息栏 ---------- */
.top-bar {
    background: var(--primary-dark);
    color: #fff;
    font-size: 15px;
    padding: 12px 0;
}
.top-bar-inner {
    display: flex;
    justify-content: space-between;
    align-items: center;
}
.top-bar-company {
    color: var(--accent);
    font-weight: 700;
    font-size: 17px;
    letter-spacing: 1px;
}
.top-bar-right { display: flex; gap: 24px; }
.top-bar-right span { white-space: nowrap; }

/* ---------- 导航栏 ---------- */
.header {
    background: var(--bg);
    box-shadow: var(--shadow);
    position: sticky;
    top: 0;
    z-index: 1000;
}
.header-inner {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 72px;
}
.logo { display: flex; align-items: center; gap: 10px; }
.logo-text {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    height: 42px;
    padding: 0 16px;
    background: linear-gradient(135deg, var(--primary), var(--primary-light));
    color: #fff;
    font-weight: 700;
    font-size: 14px;
    letter-spacing: 1px;
    white-space: nowrap;
    border-radius: var(--radius);
}
.logo-name { font-size: 18px; font-weight: 700; color: var(--text); }
.nav-list { display: flex; gap: 8px; }
.nav-link {
    display: block;
    padding: 10px 18px;
    color: var(--text);
    font-size: 15px;
    font-weight: 500;
    border-radius: var(--radius);
    position: relative;
}
.nav-link:hover { color: var(--primary); background: var(--bg-gray); }
.nav-link.active { color: var(--primary); }
.nav-link.active::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 24px;
    height: 3px;
    background: var(--accent);
    border-radius: 2px;
}

/* 移动端汉堡按钮 */
.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    padding: 8px;
}
.nav-toggle span {
    display: block;
    width: 24px;
    height: 2px;
    background: var(--text);
    border-radius: 2px;
    transition: var(--transition);
}
.nav-overlay {
    display: none;
    position: fixed;
    inset: 0;
    background: rgba(0,0,0,0.5);
    z-index: 999;
}

/* ---------- 轮播图 ---------- */
.hero {
    position: relative;
    overflow: hidden;
    height: 520px;
}
.hero-slide {
    position: absolute;
    inset: 0;
    opacity: 0;
    transition: opacity 0.8s ease;
    display: flex;
    align-items: center;
}
.hero-slide.active { opacity: 1; }
.hero-slide::before {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(135deg, rgba(10,53,96,0.75), rgba(15,76,129,0.55));
    z-index: 1;
}
.hero-bg {
    position: absolute;
    inset: 0;
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
}
.hero-content {
    position: relative;
    z-index: 2;
    color: #fff;
    max-width: 640px;
}
.hero-content h1 {
    font-size: 42px;
    font-weight: 700;
    margin-bottom: 18px;
    line-height: 1.3;
    text-shadow: 0 2px 8px rgba(0,0,0,0.3);
}
.hero-content p {
    font-size: 18px;
    margin-bottom: 32px;
    opacity: 0.92;
}
.hero-dots {
    position: absolute;
    bottom: 28px;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    gap: 10px;
    z-index: 3;
}
.hero-dot {
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background: rgba(255,255,255,0.4);
    cursor: pointer;
    transition: var(--transition);
}
.hero-dot.active { background: var(--accent); width: 32px; border-radius: 6px; }
.hero-arrow {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    width: 48px;
    height: 48px;
    border-radius: 50%;
    background: rgba(255,255,255,0.15);
    color: #fff;
    font-size: 22px;
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 3;
    transition: var(--transition);
    backdrop-filter: blur(4px);
}
.hero-arrow:hover { background: rgba(255,255,255,0.3); }
.hero-arrow.prev { left: 24px; }
.hero-arrow.next { right: 24px; }

/* ---------- 特色/优势卡片 ---------- */
.features-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
}
.feature-card {
    background: var(--bg);
    border-radius: var(--radius);
    padding: 32px 24px;
    text-align: center;
    box-shadow: var(--shadow);
    transition: var(--transition);
    border-top: 3px solid transparent;
}
.feature-card:hover {
    transform: translateY(-6px);
    box-shadow: var(--shadow-hover);
    border-top-color: var(--accent);
}
.feature-icon {
    font-size: 42px;
    margin-bottom: 16px;
}
.feature-card h3 {
    font-size: 18px;
    font-weight: 600;
    margin-bottom: 10px;
    color: var(--text);
}
.feature-card p {
    font-size: 14px;
    color: var(--text-light);
    line-height: 1.7;
}

/* ---------- 统计数据 ---------- */
.stats-section {
    background: linear-gradient(135deg, var(--primary-dark), var(--primary));
    color: #fff;
    padding: 60px 0;
}
.stats-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 20px;
    text-align: center;
}
.stat-item .stat-number {
    font-size: 42px;
    font-weight: 700;
    color: var(--accent);
    margin-bottom: 8px;
}
.stat-item .stat-label {
    font-size: 15px;
    opacity: 0.9;
}

/* ---------- 产品卡片 ---------- */
.products-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 28px;
}
.product-card {
    background: var(--bg);
    border-radius: var(--radius);
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: var(--transition);
}
.product-card:hover {
    transform: translateY(-6px);
    box-shadow: var(--shadow-hover);
}
.product-image {
    position: relative;
    aspect-ratio: 4 / 3;
    overflow: hidden;
    background: var(--bg-gray);
}
.product-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.5s ease;
}
.product-card:hover .product-image img { transform: scale(1.08); }
.product-tags {
    position: absolute;
    top: 12px;
    left: 12px;
    display: flex;
    gap: 6px;
}
.product-tag {
    padding: 4px 12px;
    background: var(--accent);
    color: #fff;
    font-size: 12px;
    border-radius: 4px;
    font-weight: 500;
}
.product-body { padding: 22px; }
.product-body h3 {
    font-size: 18px;
    font-weight: 600;
    margin-bottom: 10px;
    color: var(--text);
}
.product-body p {
    font-size: 14px;
    color: var(--text-light);
    line-height: 1.7;
    margin-bottom: 16px;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}
.product-link {
    font-size: 14px;
    font-weight: 500;
    color: var(--primary);
    display: inline-flex;
    align-items: center;
    gap: 4px;
}
.product-link:hover { color: var(--accent); gap: 8px; }

/* ---------- 关于我们 ---------- */
.about-hero {
    background: linear-gradient(135deg, var(--primary-dark), var(--primary-light));
    color: #fff;
    padding: 80px 0;
    text-align: center;
}
.about-hero h1 { font-size: 36px; margin-bottom: 16px; }
.about-hero p { font-size: 17px; opacity: 0.9; max-width: 700px; margin: 0 auto; }

.about-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 50px;
    align-items: center;
}
.about-text h2 {
    font-size: 28px;
    font-weight: 700;
    margin-bottom: 20px;
    color: var(--text);
}
.about-text p {
    color: var(--text-light);
    margin-bottom: 16px;
    line-height: 1.8;
}
.about-image {
    border-radius: var(--radius);
    overflow: hidden;
    box-shadow: var(--shadow-hover);
    background: #f7f9fc;
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 360px;
    padding: 30px;
}
.about-image img {
    max-width: 90%;
    max-height: 320px;
    width: auto;
    height: auto;
    object-fit: contain;
}

/* 发展历程时间线 */
.timeline {
    position: relative;
    max-width: 800px;
    margin: 0 auto;
    padding-left: 40px;
}
.timeline::before {
    content: '';
    position: absolute;
    left: 12px;
    top: 0;
    bottom: 0;
    width: 2px;
    background: var(--border);
}
.timeline-item {
    position: relative;
    padding-bottom: 32px;
}
.timeline-item::before {
    content: '';
    position: absolute;
    left: -34px;
    top: 6px;
    width: 14px;
    height: 14px;
    border-radius: 50%;
    background: var(--accent);
    border: 3px solid var(--bg);
    box-shadow: 0 0 0 2px var(--accent);
}
.timeline-year {
    font-size: 20px;
    font-weight: 700;
    color: var(--primary);
    margin-bottom: 6px;
}
.timeline-event { color: var(--text-light); font-size: 15px; }

/* 关于我们板块 */
.about-sections {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}
.about-section-card {
    background: var(--bg);
    padding: 32px 28px;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    border-left: 4px solid var(--primary);
}
.about-section-card h3 {
    font-size: 18px;
    font-weight: 600;
    margin-bottom: 14px;
    color: var(--primary);
}
.about-section-card p {
    font-size: 14px;
    color: var(--text-light);
    line-height: 1.8;
}

/* ---------- 产品详情页 ---------- */
.product-detail-hero {
    background: var(--bg-gray);
    padding: 50px 0;
}
.product-detail-layout {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 50px;
    align-items: start;
}
.product-detail-image {
    border-radius: var(--radius);
    overflow: hidden;
    box-shadow: var(--shadow);
    background: var(--bg);
}
.product-detail-image img { width: 100%; }
.product-detail-info h1 {
    font-size: 28px;
    font-weight: 700;
    margin-bottom: 16px;
}
.product-detail-info .product-tags { position: static; margin-bottom: 16px; }
.product-detail-desc {
    color: var(--text-light);
    line-height: 1.8;
    margin-bottom: 24px;
}
.product-detail-actions { display: flex; gap: 16px; }

/* ---------- 联系我们 ---------- */
.contact-layout {
    display: grid;
    grid-template-columns: 1fr 1.2fr;
    gap: 40px;
}
.contact-info-card {
    background: linear-gradient(135deg, var(--primary-dark), var(--primary));
    color: #fff;
    padding: 40px 32px;
    border-radius: var(--radius);
}
.contact-info-card h3 {
    font-size: 22px;
    margin-bottom: 24px;
}
.contact-info-item {
    display: flex;
    gap: 14px;
    margin-bottom: 22px;
    align-items: flex-start;
}
.contact-info-icon {
    font-size: 22px;
    flex-shrink: 0;
    width: 40px;
    height: 40px;
    background: rgba(255,255,255,0.15);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
}
.contact-info-text h4 { font-size: 15px; margin-bottom: 4px; opacity: 0.9; }
.contact-info-text p { font-size: 15px; }

/* 表单 */
.contact-form {
    background: var(--bg);
    padding: 40px 32px;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
}
.form-group { margin-bottom: 20px; }
.form-group label {
    display: block;
    font-size: 14px;
    font-weight: 500;
    margin-bottom: 8px;
    color: var(--text);
}
.form-group label .required { color: #e74c3c; }
.form-control {
    width: 100%;
    padding: 12px 16px;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    font-size: 15px;
    transition: var(--transition);
    background: var(--bg);
    color: var(--text);
}
.form-control:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(15,76,129,0.1);
}
textarea.form-control { resize: vertical; min-height: 120px; }
.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 16px;
}
.form-message {
    padding: 14px 18px;
    border-radius: var(--radius);
    margin-bottom: 20px;
    font-size: 14px;
    display: none;
}
.form-message.success { display: block; background: #d4edda; color: #155724; border: 1px solid #c3e6cb; }
.form-message.error { display: block; background: #f8d7da; color: #721c24; border: 1px solid #f5c6cb; }

/* ---------- 页脚 ---------- */
.footer {
    background: var(--bg-dark);
    color: rgba(255,255,255,0.75);
    padding: 60px 0 0;
}
.footer-grid {
    display: grid;
    grid-template-columns: 1.5fr 1fr 1.2fr;
    gap: 40px;
    padding-bottom: 40px;
}
.footer-title {
    color: #fff;
    font-size: 17px;
    font-weight: 600;
    margin-bottom: 20px;
}
.footer-desc {
    font-size: 14px;
    line-height: 1.8;
    opacity: 0.8;
}
.footer-links li { margin-bottom: 10px; }
.footer-links a {
    color: rgba(255,255,255,0.7);
    font-size: 14px;
}
.footer-links a:hover { color: var(--accent); padding-left: 4px; }
.footer-contact li {
    font-size: 14px;
    margin-bottom: 12px;
    line-height: 1.6;
}
.footer-bottom {
    border-top: 1px solid rgba(255,255,255,0.1);
    padding: 20px 0;
    text-align: center;
    font-size: 13px;
    opacity: 0.7;
}
.footer-bottom a { color: rgba(255,255,255,0.7); }
.footer-bottom a:hover { color: var(--accent); }

/* ---------- 回到顶部 ---------- */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 46px;
    height: 46px;
    border-radius: 50%;
    background: var(--primary);
    color: #fff;
    font-size: 20px;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: var(--shadow-hover);
    opacity: 0;
    visibility: hidden;
    transition: var(--transition);
    z-index: 999;
}
.back-to-top.show { opacity: 1; visibility: visible; }
.back-to-top:hover { background: var(--accent); transform: translateY(-3px); }

/* ---------- 面包屑 ---------- */
.breadcrumb {
    background: var(--bg-gray);
    padding: 16px 0;
    font-size: 14px;
    color: var(--text-light);
}
.breadcrumb a { color: var(--text-light); }
.breadcrumb a:hover { color: var(--primary); }
.breadcrumb span { margin: 0 8px; color: var(--text-muted); }

/* ---------- 视频展示区 ---------- */
.video-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 28px;
}
.video-card {
    background: var(--bg);
    border-radius: var(--radius);
    overflow: hidden;
    box-shadow: var(--shadow);
}
.video-wrapper {
    position: relative;
    aspect-ratio: 16 / 9;
    background: #000;
}
.video-wrapper video { width: 100%; height: 100%; object-fit: contain; }
.video-card-body { padding: 18px 22px; }
.video-card-body h3 { font-size: 16px; font-weight: 600; margin-bottom: 6px; }
.video-card-body p { font-size: 13px; color: var(--text-light); }

/* ---------- 空状态 ---------- */
.empty-state {
    text-align: center;
    padding: 60px 20px;
    color: var(--text-muted);
}
.empty-state .empty-icon { font-size: 48px; margin-bottom: 16px; }
.empty-state p { font-size: 15px; }

/* ============================================
   响应式
   ============================================ */

/* 平板 */
@media (max-width: 992px) {
    .features-grid { grid-template-columns: repeat(2, 1fr); }
    .products-grid { grid-template-columns: repeat(2, 1fr); }
    .stats-grid { grid-template-columns: repeat(2, 1fr); gap: 30px; }
    .about-content { grid-template-columns: 1fr; gap: 30px; }
    .about-sections { grid-template-columns: 1fr; }
    .contact-layout { grid-template-columns: 1fr; }
    .product-detail-layout { grid-template-columns: 1fr; }
    .footer-grid { grid-template-columns: repeat(2, 1fr); gap: 30px; }
    .video-grid { grid-template-columns: 1fr; }
    .hero { height: 440px; }
    .hero-content h1 { font-size: 32px; }
}

/* 手机 */
@media (max-width: 768px) {
    .section { padding: 50px 0; }
    .section-title h2 { font-size: 24px; }
    .top-bar { display: none; }
    .header-inner { height: 60px; }
    .nav-toggle { display: flex; }
    .nav {
        position: fixed;
        top: 0;
        right: -280px;
        width: 260px;
        height: 100vh;
        background: var(--bg);
        box-shadow: -4px 0 20px rgba(0,0,0,0.1);
        z-index: 1001;
        transition: right 0.3s ease;
        padding: 70px 20px 20px;
    }
    .nav.open { right: 0; }
    .nav-list { flex-direction: column; gap: 4px; }
    .nav-link { padding: 14px 16px; font-size: 16px; }
    .nav-link.active::after { display: none; }
    .nav-overlay.show { display: block; }
    .hero { height: 380px; }
    .hero-content h1 { font-size: 26px; }
    .hero-content p { font-size: 15px; margin-bottom: 24px; }
    .hero-arrow { width: 38px; height: 38px; font-size: 18px; }
    .hero-arrow.prev { left: 12px; }
    .hero-arrow.next { right: 12px; }
    .features-grid { grid-template-columns: 1fr; }
    .products-grid { grid-template-columns: 1fr; }
    .stats-grid { grid-template-columns: repeat(2, 1fr); }
    .stat-item .stat-number { font-size: 32px; }
    .form-row { grid-template-columns: 1fr; }
    .footer-grid { grid-template-columns: 1fr; gap: 28px; }
    .about-hero { padding: 50px 0; }
    .about-hero h1 { font-size: 26px; }
    .btn { padding: 10px 24px; font-size: 14px; }
    .back-to-top { width: 40px; height: 40px; bottom: 20px; right: 20px; }
}

/* 小屏手机 */
@media (max-width: 480px) {
    .hero { height: 340px; }
    .hero-content h1 { font-size: 22px; }
    .stats-grid { grid-template-columns: 1fr 1fr; }
}