/* 基础样式 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-color: #0f0f0f;
    --primary-light: #1a1a1a;
    --accent-color: #4a9eff;
    --accent-gradient: linear-gradient(135deg, #4a9eff 0%, #2563eb 100%);
    --accent-orange: #ff9800;
    --accent-orange-gradient: linear-gradient(135deg, #ff9800 0%, #f57c00 100%);
    --text-primary: #ffffff;
    --text-secondary: #a0a0a0;
    --text-muted: #6b6b6b;
    --bg-color: #080808;
    --card-bg: #141414;
    --border-color: #2a2a2a;
    --success-color: #4caf50;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Microsoft YaHei", sans-serif;
    background: var(--bg-color);
    color: var(--text-primary);
    line-height: 1.6;
}

.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 30px;
}

/* 头部导航 */
.header {
    background: rgba(15, 15, 15, 0.95);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 12px 30px;
}

.logo-link {
    display: flex;
    align-items: center;
    gap: 12px;
    text-decoration: none;
    color: inherit;
    transition: transform 0.3s;
}

.logo-link:hover {
    transform: scale(1.02);
}

.header-logo {
    height: 40px;
    width: auto;
}

.logo-text {
    display: flex;
    flex-direction: column;
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
    letter-spacing: 0.5px;
}

.tagline {
    font-size: 0.7rem;
    color: var(--text-secondary);
}

.main-nav {
    display: flex;
    gap: 6px;
}

.nav-item {
    color: var(--text-secondary);
    text-decoration: none;
    padding: 8px 16px;
    border-radius: 6px;
    font-size: 0.9rem;
    transition: all 0.3s;
}

.nav-item:hover {
    color: var(--text-primary);
    background: var(--card-bg);
}

.nav-item.highlight {
    background: var(--accent-gradient);
    color: white;
    font-weight: 600;
}

.nav-item.highlight:hover {
    transform: scale(1.05);
    box-shadow: 0 4px 15px rgba(74, 158, 255, 0.4);
}

/* Hero Banner */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    overflow: hidden;
    padding: 80px 0;
}

.hero-bg {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: 
        radial-gradient(ellipse at 20% 20%, rgba(74, 158, 255, 0.12) 0%, transparent 50%),
        radial-gradient(ellipse at 80% 80%, rgba(37, 99, 235, 0.08) 0%, transparent 50%),
        linear-gradient(180deg, var(--bg-color) 0%, var(--primary-color) 100%);
}

.hero-content {
    position: relative;
    z-index: 1;
    max-width: 1000px;
}

.hero-badge {
    display: inline-block;
    background: var(--accent-gradient);
    color: white;
    padding: 8px 20px;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 600;
    margin-bottom: 25px;
}

.hero-title {
    font-size: 3.2rem;
    font-weight: 800;
    line-height: 1.2;
    margin-bottom: 20px;
}

.hero-title .highlight-text {
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-desc {
    font-size: 1.1rem;
    color: var(--text-secondary);
    margin-bottom: 35px;
    max-width: 700px;
}

.hero-highlights {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 15px;
    margin-bottom: 35px;
}

.highlight-item {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 15px;
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid var(--border-color);
    border-radius: 10px;
    transition: all 0.3s;
}

.highlight-item:hover {
    background: rgba(74, 158, 255, 0.1);
    border-color: var(--accent-color);
}

.highlight-icon {
    font-size: 1.8rem;
}

.highlight-title {
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 2px;
}

.highlight-desc {
    font-size: 0.75rem;
    color: var(--text-secondary);
}

.hero-stats {
    display: flex;
    gap: 40px;
    margin-bottom: 35px;
}

.stat {
    display: flex;
    align-items: center;
    gap: 12px;
}

.stat-icon {
    font-size: 1.5rem;
}

.stat-number {
    font-size: 2rem;
    font-weight: 800;
    color: var(--accent-color);
    line-height: 1;
}

.stat-label {
    font-size: 0.85rem;
    color: var(--text-secondary);
}

.hero-actions {
    display: flex;
    gap: 15px;
}

.btn {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    padding: 14px 30px;
    border-radius: 8px;
    font-size: 0.95rem;
    font-weight: 600;
    text-decoration: none;
    transition: all 0.3s;
    cursor: pointer;
    border: none;
}

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

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(74, 158, 255, 0.4);
}

.btn-secondary {
    background: transparent;
    color: var(--text-primary);
    border: 2px solid var(--border-color);
}

.btn-secondary:hover {
    border-color: var(--accent-color);
    background: rgba(74, 158, 255, 0.1);
}

.btn-outline {
    background: transparent;
    color: var(--accent-color);
    border: 2px solid var(--accent-color);
}

.btn-outline:hover {
    background: var(--accent-color);
    color: white;
}

.btn-small {
    padding: 10px 20px;
    font-size: 0.9rem;
}

.btn-orange {
    background: var(--accent-orange-gradient);
    color: white;
}

.btn-arrow {
    transition: transform 0.3s;
}

.btn:hover .btn-arrow {
    transform: translateX(5px);
}

/* 通用章节 */
section {
    padding: 80px 0;
}

.section-header {
    text-align: center;
    margin-bottom: 50px;
}

.section-badge {
    display: inline-block;
    background: rgba(74, 158, 255, 0.15);
    color: var(--accent-color);
    padding: 6px 16px;
    border-radius: 15px;
    font-size: 0.8rem;
    font-weight: 600;
    margin-bottom: 15px;
}

.section-title {
    font-size: 2.2rem;
    font-weight: 800;
    margin-bottom: 12px;
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.section-subtitle {
    font-size: 1rem;
    color: var(--text-secondary);
}

/* 方案概述 */
.overview {
    background: var(--primary-color);
}

.principle-content {
    margin-bottom: 60px;
}

.principle-main {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    padding: 40px;
}

.principle-text h3 {
    font-size: 1.5rem;
    margin-bottom: 20px;
}

.principle-text > p {
    font-size: 1rem;
    color: var(--text-secondary);
    margin-bottom: 30px;
    line-height: 1.8;
}

.tech-features {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 20px;
}

.tech-item {
    display: flex;
    gap: 15px;
    padding: 20px;
    background: var(--primary-color);
    border-radius: 10px;
    transition: all 0.3s;
}

.tech-item:hover {
    background: rgba(74, 158, 255, 0.1);
}

.tech-icon {
    font-size: 2rem;
}

.tech-info h4 {
    font-size: 1rem;
    margin-bottom: 8px;
}

.tech-info p {
    font-size: 0.85rem;
    color: var(--text-secondary);
    line-height: 1.6;
}

/* 技术对比表 */
.tech-comparison {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    overflow: hidden;
}

.comparison-title {
    font-size: 1.3rem;
    padding: 25px 30px;
    border-bottom: 1px solid var(--border-color);
    background: linear-gradient(135deg, rgba(74, 158, 255, 0.1) 0%, transparent 100%);
}

.comparison-table {
    padding: 20px;
}

.table-header {
    display: grid;
    grid-template-columns: 1fr 1fr 1fr;
    gap: 15px;
    margin-bottom: 15px;
    padding: 15px;
    background: var(--primary-color);
    border-radius: 8px;
}

.th {
    font-weight: 600;
    font-size: 0.9rem;
    color: var(--text-primary);
}

.th.traditional {
    color: var(--text-secondary);
}

.th.magnetic {
    color: var(--accent-color);
}

.table-row {
    display: grid;
    grid-template-columns: 1fr 1fr 1fr;
    gap: 15px;
    padding: 20px 15px;
    border-bottom: 1px solid var(--border-color);
}

.table-row:last-child {
    border-bottom: none;
}

.td {
    display: flex;
    flex-direction: column;
    gap: 5px;
}

.td.label {
    font-weight: 600;
    color: var(--text-primary);
}

.level {
    display: inline-block;
    padding: 4px 12px;
    border-radius: 12px;
    font-size: 0.75rem;
    font-weight: 600;
    width: fit-content;
}

.level-low {
    background: rgba(244, 67, 54, 0.2);
    color: #f44336;
}

.level-mid {
    background: rgba(255, 152, 0, 0.2);
    color: #ff9800;
}

.level-high {
    background: rgba(76, 175, 80, 0.2);
    color: #4caf50;
}

.detail {
    font-size: 0.75rem;
    color: var(--text-muted);
}

.time {
    font-weight: 600;
    color: var(--text-primary);
}

.time.highlight {
    color: var(--accent-color);
    font-size: 1.1rem;
}

.cost {
    font-weight: 600;
}

.cost.highlight {
    color: var(--success-color);
}

/* 产品系列 */
.series {
    background: var(--bg-color);
}

.product-block {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    margin-bottom: 40px;
    overflow: hidden;
}

.product-header {
    background: linear-gradient(135deg, rgba(74, 158, 255, 0.08) 0%, rgba(37, 99, 235, 0.04) 100%);
    padding: 30px;
    border-bottom: 1px solid var(--border-color);
}

.product-series {
    display: flex;
    align-items: center;
    gap: 15px;
    margin-bottom: 15px;
}

.series-badge {
    padding: 6px 14px;
    border-radius: 15px;
    font-size: 0.75rem;
    font-weight: 700;
}

.badge-5v {
    background: var(--accent-gradient);
    color: white;
}

.badge-12v {
    background: var(--accent-orange-gradient);
    color: white;
}

.product-title {
    font-size: 1.8rem;
    font-weight: 700;
}

.product-intro {
    font-size: 1rem;
    color: var(--text-secondary);
    line-height: 1.7;
}

.product-body {
    padding: 30px;
}

/* 规格参数 */
.specs-section,
.features-section,
.brands-section,
.sizes-section,
.gallery-section,
.cases-section {
    margin-bottom: 35px;
}

.specs-title,
.features-title,
.brands-title,
.sizes-title,
.gallery-title,
.cases-title {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 1.1rem;
    margin-bottom: 20px;
}

.specs-icon,
.features-icon,
.brands-icon,
.sizes-icon,
.gallery-icon,
.cases-icon {
    font-size: 1.3rem;
}

.specs-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 15px;
}

.spec-card {
    background: var(--primary-color);
    border: 1px solid var(--border-color);
    border-radius: 10px;
    padding: 20px;
    transition: all 0.3s;
}

.spec-card:hover,
.spec-card.highlight {
    border-color: var(--accent-color);
    background: rgba(74, 158, 255, 0.1);
}

.spec-label {
    font-size: 0.8rem;
    color: var(--text-muted);
    margin-bottom: 8px;
}

.spec-value {
    font-size: 1.3rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 5px;
}

.spec-note {
    font-size: 0.75rem;
    color: var(--text-secondary);
}

/* 产品特点 */
.features-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 15px;
}

.feature-card {
    background: var(--primary-color);
    border: 1px solid var(--border-color);
    border-radius: 10px;
    padding: 25px 20px;
    text-align: center;
    transition: all 0.3s;
}

.feature-card:hover {
    border-color: var(--accent-color);
    transform: translateY(-5px);
}

.feature-icon {
    font-size: 2.2rem;
    margin-bottom: 15px;
}

.feature-card h5 {
    font-size: 0.95rem;
    margin-bottom: 10px;
}

.feature-card p {
    font-size: 0.8rem;
    color: var(--text-secondary);
    line-height: 1.6;
}

/* 兼容品牌 */
.brands-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 12px;
}

.brand-item {
    background: var(--primary-color);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 15px;
    transition: all 0.3s;
}

.brand-item:hover {
    border-color: var(--accent-color);
}

.brand-name {
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: 5px;
}

.brand-models {
    font-size: 0.75rem;
    color: var(--text-secondary);
}

.brand-item.brand-pro {
    background: linear-gradient(135deg, rgba(255, 152, 0, 0.15), rgba(245, 124, 0, 0.08));
    border-color: rgba(255, 152, 0, 0.3);
}

.brand-item.brand-pro .brand-name {
    color: var(--accent-orange);
}

/* 尺寸适配 */
.sizes-desc {
    font-size: 0.9rem;
    color: var(--text-secondary);
    margin-bottom: 20px;
}

.sizes-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 15px;
}

.size-item {
    position: relative;
    border-radius: 10px;
    overflow: hidden;
    cursor: pointer;
    border: 1px solid var(--border-color);
    transition: all 0.3s;
}

.size-item:hover {
    border-color: var(--accent-color);
    transform: scale(1.02);
}

.size-item img {
    width: 100%;
    height: 150px;
    object-fit: cover;
    background: white;
}

.size-overlay {
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    background: linear-gradient(to top, rgba(0, 0, 0, 0.9), transparent);
    padding: 30px 15px 15px;
    display: flex;
    flex-direction: column;
    gap: 5px;
}

.size-brand {
    font-size: 0.9rem;
    font-weight: 600;
    color: white;
}

.size-hint {
    font-size: 0.7rem;
    color: rgba(255, 255, 255, 0.7);
}

/* 产品展示 */
.gallery-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 15px;
}

.gallery-grid.gallery-triple {
    grid-template-columns: repeat(3, 1fr);
}

.gallery-grid.gallery-quad {
    grid-template-columns: repeat(4, 1fr);
}

.gallery-item {
    position: relative;
    border-radius: 10px;
    overflow: hidden;
    cursor: pointer;
    border: 1px solid var(--border-color);
    transition: all 0.3s;
}

.gallery-item:hover {
    border-color: var(--accent-color);
    transform: scale(1.02);
}

.gallery-item img {
    width: 100%;
    height: 180px;
    object-fit: cover;
    background: white;
}

.gallery-overlay {
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    background: linear-gradient(to top, rgba(0, 0, 0, 0.9), transparent);
    padding: 30px 15px 15px;
    display: flex;
    flex-direction: column;
    gap: 5px;
}

.gallery-label {
    font-size: 0.9rem;
    font-weight: 600;
    color: white;
}

.gallery-hint {
    font-size: 0.7rem;
    color: rgba(255, 255, 255, 0.7);
}

/* 应用案例 */
.cases-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 15px;
}

.case-item {
    position: relative;
    border-radius: 10px;
    overflow: hidden;
    cursor: pointer;
    border: 1px solid var(--border-color);
    transition: all 0.3s;
}

.case-item:hover {
    border-color: var(--accent-color);
    transform: translateY(-5px);
}

.case-item img {
    width: 100%;
    height: 160px;
    object-fit: cover;
    background: white;
}

.case-info {
    padding: 15px;
    background: var(--primary-color);
    display: flex;
    flex-direction: column;
    gap: 5px;
}

.case-brand {
    font-size: 0.9rem;
    font-weight: 600;
}

.case-desc {
    font-size: 0.75rem;
    color: var(--text-secondary);
}

/* 方案对比 */
.comparison {
    background: var(--primary-color);
}

.comparison-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 30px;
}

.comparison-grid-4 {
    grid-template-columns: repeat(4, 1fr);
    gap: 20px;
}

.comparison-card {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    overflow: hidden;
    transition: all 0.3s;
}

.comparison-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 40px rgba(0, 0, 0, 0.3);
}

.card-header {
    padding: 25px;
    border-bottom: 1px solid var(--border-color);
}

.card-badge {
    display: inline-block;
    padding: 6px 14px;
    border-radius: 15px;
    font-size: 0.75rem;
    font-weight: 700;
    margin-bottom: 12px;
}

.card-body {
    padding: 25px;
}

.use-case {
    margin-bottom: 20px;
}

.use-case h4,
.choose-reason h4 {
    font-size: 0.95rem;
    margin-bottom: 12px;
}

.use-case ul {
    list-style: none;
}

.use-case li {
    padding: 6px 0;
    font-size: 0.9rem;
    color: var(--text-secondary);
}

.choose-reason p {
    font-size: 0.9rem;
    color: var(--text-secondary);
    line-height: 1.7;
}

.card-cta {
    margin-top: 20px;
}

/* 安装指南 */
.installation {
    background: var(--bg-color);
}

.steps-grid {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 20px;
    margin-bottom: 40px;
}

.step-card {
    flex: 1;
    max-width: 300px;
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    padding: 30px;
    text-align: center;
    position: relative;
    transition: all 0.3s;
}

.step-card:hover {
    border-color: var(--accent-color);
    transform: translateY(-5px);
}

.step-number {
    position: absolute;
    top: -15px;
    left: 20px;
    background: var(--accent-gradient);
    color: white;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 1.1rem;
}

.step-icon {
    font-size: 3rem;
    margin-bottom: 15px;
}

.step-card h3 {
    font-size: 1.2rem;
    margin-bottom: 12px;
}

.step-card p {
    font-size: 0.9rem;
    color: var(--text-secondary);
    line-height: 1.6;
    margin-bottom: 15px;
}

.step-tip {
    background: rgba(74, 158, 255, 0.1);
    color: var(--accent-color);
    padding: 10px 15px;
    border-radius: 8px;
    font-size: 0.8rem;
}

.step-arrow {
    font-size: 2rem;
    color: var(--text-muted);
}

.install-faq {
    text-align: center;
}

/* 视频教程 */
.video-section {
    background: var(--bg-color);
}

.video-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 30px;
}

.video-card {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    overflow: hidden;
    transition: all 0.3s;
}

.video-card:hover {
    border-color: var(--accent-color);
    transform: translateY(-5px);
    box-shadow: 0 15px 40px rgba(0, 0, 0, 0.3);
}

.video-wrapper {
    position: relative;
    width: 100%;
    padding-bottom: 56.25%; /* 16:9 比例 */
    background: #000;
}

.video-wrapper iframe {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    border: none;
}

.video-cover {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, rgba(74, 158, 255, 0.3) 0%, rgba(37, 99, 235, 0.4) 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all 0.3s;
    z-index: 10;
}

.video-cover:hover {
    background: linear-gradient(135deg, rgba(74, 158, 255, 0.4) 0%, rgba(37, 99, 235, 0.5) 100%);
}

.video-cover:hover .play-btn {
    transform: scale(1.1);
    box-shadow: 0 0 30px rgba(74, 158, 255, 0.6);
}

.play-btn {
    width: 70px;
    height: 70px;
    background: var(--accent-gradient);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 24px;
    color: white;
    box-shadow: 0 8px 25px rgba(74, 158, 255, 0.5);
    transition: all 0.3s;
    padding-left: 5px;
}

.video-info {
    padding: 20px;
}

.video-info h4 {
    font-size: 1.1rem;
    margin-bottom: 8px;
    color: var(--text-primary);
}

.video-info p {
    font-size: 0.9rem;
    color: var(--text-secondary);
}

/* 常见问题 */
.faq-section {
    background: var(--primary-color);
}

.faq-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 15px;
    margin-bottom: 30px;
}

.faq-card {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 25px;
    cursor: pointer;
    transition: all 0.3s;
}

.faq-card:hover {
    border-color: var(--accent-color);
    transform: translateY(-5px);
}

.faq-icon {
    font-size: 2rem;
    margin-bottom: 15px;
}

.faq-card h4 {
    font-size: 1rem;
    margin-bottom: 8px;
}

.faq-card p {
    font-size: 0.8rem;
    color: var(--text-secondary);
}

.faq-more {
    text-align: center;
}

/* 页脚 */
.footer {
    background: var(--primary-color);
    padding: 50px 0 25px;
    border-top: 1px solid var(--border-color);
}

.footer-content {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1.5fr;
    gap: 40px;
    margin-bottom: 30px;
}

.footer-logo {
    height: 45px;
    margin-bottom: 12px;
}

.company-info h3 {
    font-size: 1.2rem;
    margin-bottom: 10px;
}

.company-desc {
    font-size: 0.85rem;
    color: var(--text-secondary);
    line-height: 1.7;
}

.footer-links h4,
.shop-links h4,
.wechat-qrcode h4 {
    font-size: 0.95rem;
    margin-bottom: 15px;
}

.footer-links a {
    display: block;
    color: var(--text-secondary);
    text-decoration: none;
    padding: 6px 0;
    font-size: 0.85rem;
    transition: color 0.3s;
}

.footer-links a:hover {
    color: var(--accent-color);
}

.shop-links a {
    display: flex;
    align-items: center;
    gap: 8px;
    color: var(--text-secondary);
    text-decoration: none;
    padding: 8px 0;
    font-size: 0.85rem;
    transition: color 0.3s;
}

.shop-links a:hover {
    color: var(--accent-color);
}

.wechat-qrcode {
    text-align: center;
}

.qr-image {
    width: 110px;
    height: 110px;
    object-fit: contain;
    border-radius: 8px;
    background: white;
    padding: 8px;
    margin-bottom: 8px;
}

.wechat-qrcode p {
    font-size: 0.8rem;
    color: var(--text-secondary);
}

.copyright {
    text-align: center;
    padding-top: 25px;
    border-top: 1px solid var(--border-color);
    color: var(--text-muted);
    font-size: 0.8rem;
}

/* 在线客服 */
.floating-cs {
    position: fixed;
    right: 30px;
    bottom: 100px;
    background: var(--accent-gradient);
    color: white;
    padding: 14px 22px;
    border-radius: 50px;
    text-decoration: none;
    box-shadow: 0 8px 25px rgba(74, 158, 255, 0.4);
    transition: all 0.3s;
    z-index: 9999;
    display: flex;
    align-items: center;
    gap: 8px;
    font-weight: 600;
    font-size: 0.9rem;
}

.floating-cs:hover {
    transform: scale(1.1);
    box-shadow: 0 12px 35px rgba(74, 158, 255, 0.5);
}

.cs-icon {
    font-size: 1.4rem;
}

/* 模态框 */
.modal {
    display: none;
    position: fixed;
    z-index: 10000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    overflow: auto;
    background-color: rgba(0, 0, 0, 0.95);
    backdrop-filter: blur(10px);
    align-items: center;
    justify-content: center;
}

.modal-content {
    display: block;
    width: 90%;
    max-width: 1400px;
    max-height: 90vh;
    object-fit: contain;
    border-radius: 12px;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.5);
}

.close-btn {
    position: absolute;
    top: 30px;
    right: 40px;
    color: white;
    font-size: 50px;
    font-weight: bold;
    cursor: pointer;
    transition: all 0.3s;
    z-index: 10001;
    background: rgba(0, 0, 0, 0.6);
    width: 60px;
    height: 60px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    line-height: 1;
}

.close-btn:hover {
    background: rgba(255, 0, 0, 0.7);
    transform: scale(1.1);
}

/* 响应式 */
@media (max-width: 1200px) {
    .features-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .brands-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .sizes-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .cases-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .faq-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .footer-content {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 992px) {
    .hero-highlights {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .hero-stats {
        flex-wrap: wrap;
    }
    
    .tech-features {
        grid-template-columns: 1fr;
    }
    
    .specs-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .comparison-grid {
        grid-template-columns: 1fr;
    }

    .comparison-grid-4 {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .steps-grid {
        flex-direction: column;
    }
    
    .step-arrow {
        transform: rotate(90deg);
    }
    
    .gallery-grid.gallery-quad {
        grid-template-columns: repeat(2, 1fr);
    }

    .video-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 768px) {
    .header .container {
        flex-direction: column;
        gap: 12px;
    }
    
    .main-nav {
        flex-wrap: wrap;
        justify-content: center;
    }
    
    .hero-title {
        font-size: 2.2rem;
    }
    
    .hero-highlights {
        grid-template-columns: 1fr;
    }
    
    .hero-stats {
        gap: 20px;
    }
    
    .hero-actions {
        flex-direction: column;
    }
    
    .section-title {
        font-size: 1.8rem;
    }
    
    .specs-grid {
        grid-template-columns: 1fr;
    }
    
    .features-grid {
        grid-template-columns: 1fr;
    }
    
    .brands-grid {
        grid-template-columns: 1fr;
    }
    
    .sizes-grid {
        grid-template-columns: 1fr;
    }
    
    .gallery-grid,
    .gallery-grid.gallery-triple,
    .gallery-grid.gallery-quad {
        grid-template-columns: 1fr;
    }
    
    .cases-grid {
        grid-template-columns: 1fr;
    }
    
    .faq-grid {
        grid-template-columns: 1fr;
    }
    
    .table-header,
    .table-row {
        grid-template-columns: 1fr;
        gap: 10px;
    }
    
    .td.label {
        font-weight: 700;
        margin-bottom: 5px;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
        text-align: center;
    }
    
    .floating-cs {
        right: 20px;
        bottom: 80px;
        padding: 12px 18px;
    }
}