/* 
 * EADC 官方网站样式文件
 * 半主动悬架控制系统
 */

/* ===== CSS 变量定义 ===== */
:root {
    --primary-color: #0056b3;
    --primary-dark: #003d82;
    --primary-light: #007bff;
    --secondary-color: #00c4cc;
    --accent-color: #ff6b35;
    --text-color: #333333;
    --text-light: #666666;
    --text-lighter: #999999;
    --bg-color: #ffffff;
    --bg-light: #f8f9fa;
    --bg-dark: #1a1a2e;
    --border-color: #e0e0e0;
    --shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
    --shadow-hover: 0 8px 30px rgba(0, 0, 0, 0.15);
    --transition: all 0.3s ease;
    --border-radius: 8px;
}

/* ===== 全局样式 ===== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Segoe UI', 'PingFang SC', 'Microsoft YaHei', sans-serif;
    font-size: 16px;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--bg-color);
    overflow-x: hidden;
}

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

a {
    text-decoration: none;
    color: inherit;
    transition: var(--transition);
}

ul {
    list-style: none;
}

img {
    max-width: 100%;
    height: auto;
}

/* ===== 按钮样式 ===== */
.btn {
    display: inline-block;
    padding: 12px 30px;
    font-size: 16px;
    font-weight: 600;
    text-align: center;
    border: none;
    border-radius: var(--border-radius);
    cursor: pointer;
    transition: var(--transition);
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary-color), var(--primary-light));
    color: white;
}

.btn-primary:hover {
    background: linear-gradient(135deg, var(--primary-dark), var(--primary-color));
    transform: translateY(-2px);
    box-shadow: var(--shadow);
}

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

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

.btn-block {
    display: block;
    width: 100%;
}

/* ===== 头部导航 ===== */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    transition: var(--transition);
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 70px;
}

.logo a {
    display: flex;
    align-items: center;
}

.logo-image {
    height: 110px;
    width: auto;
    max-width: 400px;
}

.main-nav {
    display: flex;
}

.nav-list {
    display: flex;
    gap: 30px;
}

.nav-link {
    font-weight: 500;
    color: var(--text-color);
    position: relative;
    padding: 5px 0;
}

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

.nav-link:hover::after,
.nav-link.active::after {
    width: 100%;
}

.nav-link:hover,
.nav-link.active {
    color: var(--primary-color);
}

.mobile-menu-btn {
    display: none;
    font-size: 24px;
    cursor: pointer;
    color: var(--text-color);
}

/* ===== 英雄轮播区域 ===== */
.hero-slider {
    position: relative;
    height: 100vh;
    overflow: hidden;
    margin-top: 0;
}

.slider-container {
    height: 100%;
    position: relative;
}

.slide {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-size: cover;
    background-position: center;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    visibility: hidden;
    transition: all 0.8s ease;
}

.slide.active {
    opacity: 1;
    visibility: visible;
}

.slide::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, rgba(0, 86, 179, 0.8), rgba(0, 196, 204, 0.6));
}

.slide-content {
    position: relative;
    z-index: 2;
    text-align: center;
    color: white;
    max-width: 800px;
    padding: 20px;
}

.slide-title {
    font-size: 48px;
    font-weight: 700;
    margin-bottom: 15px;
    text-shadow: 2px 2px 10px rgba(0, 0, 0, 0.3);
}

.slide-subtitle {
    font-size: 24px;
    margin-bottom: 20px;
    opacity: 0.9;
}

.slide-description {
    font-size: 18px;
    margin-bottom: 30px;
    opacity: 0.85;
}

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

.slide .btn-primary:hover {
    background: rgba(255, 255, 255, 0.9);
    transform: translateY(-2px);
}

.slider-controls {
    position: absolute;
    top: 50%;
    left: 0;
    right: 0;
    transform: translateY(-50%);
    display: flex;
    justify-content: space-between;
    padding: 0 20px;
    z-index: 3;
}

.slider-btn {
    width: 50px;
    height: 50px;
    background: rgba(255, 255, 255, 0.2);
    border: none;
    border-radius: 50%;
    color: white;
    font-size: 20px;
    cursor: pointer;
    transition: var(--transition);
}

.slider-btn:hover {
    background: rgba(255, 255, 255, 0.4);
}

.slider-dots {
    position: absolute;
    bottom: 30px;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    gap: 15px;
    z-index: 3;
}

.dot {
    width: 12px;
    height: 12px;
    background: rgba(255, 255, 255, 0.5);
    border-radius: 50%;
    cursor: pointer;
    transition: var(--transition);
}

.dot.active {
    background: white;
    transform: scale(1.2);
}

/* ===== 统计区域 ===== */
.stats-section {
    background: var(--bg-dark);
    padding: 60px 0;
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(6, 1fr);
    gap: 30px;
}

.stat-item {
    text-align: center;
    color: white;
}

.stat-icon {
    font-size: 36px;
    color: var(--secondary-color);
    margin-bottom: 15px;
}

.stat-number {
    font-size: 48px;
    font-weight: 700;
    display: inline;
    background: linear-gradient(135deg, var(--primary-light), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.stat-unit {
    font-size: 24px;
    font-weight: 600;
    color: var(--secondary-color);
}

.stat-label {
    font-size: 14px;
    margin-top: 10px;
    color: rgba(255, 255, 255, 0.8);
}

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

.section-title {
    font-size: 36px;
    font-weight: 700;
    color: var(--text-color);
    margin-bottom: 10px;
}

.section-subtitle {
    font-size: 18px;
    color: var(--text-light);
}

/* ===== 关于我们区域 ===== */
.about-section {
    padding: 100px 0;
    background: var(--bg-light);
}

.about-content {
    display: grid;
    grid-template-columns: 1.2fr 0.8fr;
    gap: 60px;
    align-items: center;
}

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

.about-text p {
    font-size: 16px;
    color: var(--text-light);
    margin-bottom: 20px;
    line-height: 1.8;
}

.about-features {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
    margin-top: 30px;
}

.feature-item {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 15px;
    background: white;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
}

.feature-item i {
    font-size: 24px;
    color: var(--primary-color);
}

.feature-item span {
    font-size: 14px;
    font-weight: 500;
    color: var(--text-color);
}

.about-image {
    display: flex;
    justify-content: center;
    align-items: center;
}

.image-frame {
    width: 400px;
    height: 400px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    border-radius: 20px;
    display: flex;
    justify-content: center;
    align-items: center;
    color: white;
    box-shadow: var(--shadow-hover);
}

.image-frame i {
    opacity: 0.3;
}

/* ===== 技术优势区域 ===== */
.technology-section {
    padding: 100px 0;
    background: white;
}

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

.tech-card {
    padding: 40px 30px;
    background: var(--bg-light);
    border-radius: var(--border-radius);
    text-align: center;
    transition: var(--transition);
}

.tech-card:hover {
    transform: translateY(-10px);
    box-shadow: var(--shadow-hover);
    background: white;
}

.tech-icon {
    width: 80px;
    height: 80px;
    margin: 0 auto 20px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    border-radius: 50%;
    display: flex;
    justify-content: center;
    align-items: center;
}

.tech-icon i {
    font-size: 36px;
    color: white;
}

.tech-card h3 {
    font-size: 20px;
    color: var(--text-color);
    margin-bottom: 15px;
}

.tech-card p {
    font-size: 14px;
    color: var(--text-light);
    line-height: 1.7;
}

/* ===== 技术规格区域 ===== */
.specs-section {
    padding: 100px 0;
    background: var(--bg-light);
}

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

.spec-card {
    background: white;
    border-radius: var(--border-radius);
    overflow: hidden;
    transition: var(--transition);
    box-shadow: var(--shadow);
}

.spec-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-hover);
}

.spec-header {
    padding: 25px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    display: flex;
    align-items: center;
    gap: 15px;
}

.spec-header i {
    font-size: 28px;
    color: white;
}

.spec-header h3 {
    font-size: 18px;
    color: white;
    margin: 0;
}

.spec-content {
    padding: 25px;
}

.spec-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 12px 0;
    border-bottom: 1px solid var(--border-color);
}

.spec-item:last-child {
    border-bottom: none;
}

.spec-label {
    font-size: 14px;
    color: var(--text-light);
}

.spec-value {
    font-size: 14px;
    font-weight: 600;
    color: var(--primary-color);
}

/* ===== 产品型号列表区域 ===== */
.products-list-section {
    padding: 80px 0;
    background: white;
}

.products-list-content {
    max-width: 1000px;
    margin: 0 auto;
}

.product-series {
    margin-bottom: 50px;
}

.product-series h3,
.optional-equipment h3 {
    font-size: 22px;
    color: var(--text-color);
    margin-bottom: 25px;
    display: flex;
    align-items: center;
    gap: 10px;
}

.product-series h3 i,
.optional-equipment h3 i {
    color: var(--primary-color);
}

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

.series-item {
    padding: 30px 20px;
    border-radius: var(--border-radius);
    text-align: center;
    transition: var(--transition);
    box-shadow: var(--shadow);
}

.series-item:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-hover);
}

.series-item.basic {
    background: linear-gradient(135deg, #f8f9fa, #e9ecef);
    border: 2px solid #dee2e6;
}

.series-item.pro {
    background: linear-gradient(135deg, #e3f2fd, #bbdefb);
    border: 2px solid #90caf9;
}

.series-item.plus {
    background: linear-gradient(135deg, #e8f5e9, #c8e6c9);
    border: 2px solid #81c784;
}

.series-item.max {
    background: linear-gradient(135deg, #fff3e0, #ffe0b2);
    border: 2px solid #ffb74d;
}

.series-badge {
    display: inline-block;
    padding: 8px 20px;
    border-radius: 20px;
    font-size: 14px;
    font-weight: 700;
    margin-bottom: 15px;
}

.series-item.basic .series-badge {
    background: var(--text-light);
    color: white;
}

.series-item.pro .series-badge {
    background: var(--primary-color);
    color: white;
}

.series-item.plus .series-badge {
    background: #2e7d32;
    color: white;
}

.series-item.max .series-badge {
    background: #ef6c00;
    color: white;
}

.series-name {
    font-size: 20px;
    font-weight: 600;
    color: var(--text-color);
    margin-bottom: 10px;
}

.series-desc {
    font-size: 13px;
    color: var(--text-light);
    line-height: 1.5;
}

.optional-equipment {
    margin-bottom: 40px;
}

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

.equipment-item {
    display: flex;
    align-items: flex-start;
    gap: 15px;
    padding: 25px;
    background: var(--bg-light);
    border-radius: var(--border-radius);
    transition: var(--transition);
}

.equipment-item:hover {
    transform: translateX(5px);
    box-shadow: var(--shadow);
}

.equipment-item i {
    font-size: 28px;
    color: var(--primary-color);
    margin-top: 3px;
}

.equipment-info h4 {
    font-size: 16px;
    color: var(--text-color);
    margin-bottom: 8px;
}

.equipment-info p {
    font-size: 13px;
    color: var(--text-light);
    line-height: 1.5;
}

.core-technology {
    text-align: center;
    padding: 30px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    border-radius: var(--border-radius);
}

.tech-badge {
    display: inline-flex;
    align-items: center;
    gap: 15px;
    color: white;
    font-size: 18px;
    font-weight: 600;
}

.tech-badge i {
    font-size: 32px;
}

/* ===== 性能指标说明区域 ===== */
.performance-metrics-section {
    padding: 80px 0;
    background: white;
}

.metrics-content {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
    margin-bottom: 40px;
}

.metrics-panel {
    background: var(--bg-light);
    border-radius: var(--border-radius);
    overflow: hidden;
}

.metrics-panel h3 {
    padding: 20px 25px;
    font-size: 18px;
    color: white;
    display: flex;
    align-items: center;
    gap: 10px;
}

.metrics-panel.comfort h3 {
    background: linear-gradient(135deg, var(--primary-color), var(--primary-light));
}

.metrics-panel.safety h3 {
    background: linear-gradient(135deg, #2e7d32, #4caf50);
}

.metrics-panel.stability h3 {
    background: linear-gradient(135deg, #ef6c00, #ff9800);
}

.metrics-list {
    padding: 20px 25px;
}

.metric-item {
    padding: 18px 0;
    border-bottom: 1px solid var(--border-color);
}

.metric-item:last-child {
    border-bottom: none;
}

.metric-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 10px;
}

.metric-name {
    font-size: 14px;
    font-weight: 600;
    color: var(--text-color);
}

.metric-value {
    font-size: 16px;
    font-weight: 700;
    padding: 4px 12px;
    border-radius: 15px;
}

.metric-value.improvement {
    background: linear-gradient(135deg, #e8f5e9, #c8e6c9);
    color: #2e7d32;
}

.metric-desc {
    font-size: 13px;
    color: var(--text-light);
    margin-bottom: 10px;
    line-height: 1.5;
}

.metric-reference {
    font-size: 11px;
    color: var(--text-lighter);
    font-style: italic;
}

.metrics-note {
    display: flex;
    align-items: flex-start;
    gap: 20px;
    padding: 25px;
    background: #fff8e1;
    border-radius: var(--border-radius);
    border-left: 4px solid #ffc107;
}

.note-icon {
    font-size: 28px;
    color: #ffc107;
}

.note-content h4 {
    font-size: 16px;
    color: var(--text-color);
    margin-bottom: 10px;
}

.note-content p {
    font-size: 13px;
    color: var(--text-light);
    line-height: 1.6;
}

/* ===== 产品中心区域 ===== */
.products-section {
    padding: 100px 0;
    background: var(--bg-light);
}

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

.product-card {
    background: white;
    border-radius: var(--border-radius);
    overflow: hidden;
    transition: var(--transition);
    box-shadow: var(--shadow);
}

.product-card:hover {
    transform: translateY(-10px);
    box-shadow: var(--shadow-hover);
}

.product-image {
    height: 200px;
    background: linear-gradient(135deg, var(--primary-dark), var(--primary-color));
    display: flex;
    justify-content: center;
    align-items: center;
    color: white;
}

.product-image i {
    opacity: 0.3;
}

.product-info {
    padding: 30px;
}

.product-info h3 {
    font-size: 24px;
    color: var(--primary-color);
    margin-bottom: 10px;
}

.product-category {
    font-size: 14px;
    color: var(--secondary-color);
    margin-bottom: 15px;
}

.product-description {
    font-size: 14px;
    color: var(--text-light);
    margin-bottom: 20px;
    line-height: 1.6;
}

/* ===== 应用场景区域 ===== */
.applications-section {
    padding: 100px 0;
    background: white;
}

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

.app-card {
    border-radius: var(--border-radius);
    overflow: hidden;
    transition: var(--transition);
}

.app-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-hover);
}

.app-image {
    height: 250px;
    background-size: cover;
    background-position: center;
    position: relative;
}

.app-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(135deg, rgba(0, 86, 179, 0.8), rgba(0, 196, 204, 0.6));
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    color: white;
    opacity: 0;
    transition: var(--transition);
}

.app-card:hover .app-overlay {
    opacity: 1;
}

.app-overlay h3 {
    font-size: 24px;
    margin-bottom: 5px;
}

.app-overlay p {
    font-size: 14px;
    text-transform: uppercase;
    letter-spacing: 2px;
}

.app-content {
    padding: 20px;
    background: var(--bg-light);
}

.app-content p {
    font-size: 14px;
    color: var(--text-light);
}

/* ===== 客户案例区域 ===== */
.cases-section {
    padding: 100px 0;
    background: var(--bg-light);
}

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

.case-card {
    background: white;
    border-radius: var(--border-radius);
    overflow: hidden;
    transition: var(--transition);
    box-shadow: var(--shadow);
}

.case-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-hover);
}

.case-image {
    height: 200px;
    background-size: cover;
    background-position: center;
    background-color: var(--primary-color);
}

.case-content {
    padding: 25px;
}

.case-content h3 {
    font-size: 18px;
    color: var(--primary-color);
    margin-bottom: 10px;
}

.case-content p {
    font-size: 14px;
    color: var(--text-light);
    line-height: 1.6;
}

/* ===== 合作伙伴区域 ===== */
.partners-section {
    padding: 80px 0;
    background: white;
}

.partners-grid {
    display: grid;
    grid-template-columns: repeat(6, 1fr);
    gap: 30px;
    align-items: center;
}

.partner-item {
    text-align: center;
    padding: 20px;
    background: var(--bg-light);
    border-radius: var(--border-radius);
    transition: var(--transition);
}

.partner-item:hover {
    transform: scale(1.05);
    box-shadow: var(--shadow);
}

.partner-logo {
    width: 60px;
    height: 60px;
    margin: 0 auto 10px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    border-radius: 50%;
    display: flex;
    justify-content: center;
    align-items: center;
}

.partner-logo i {
    color: white;
    font-size: 24px;
}

.partner-item span {
    font-size: 14px;
    font-weight: 600;
    color: var(--text-color);
}

/* ===== 新闻中心区域 ===== */
.news-section {
    padding: 100px 0;
    background: var(--bg-light);
}

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

.news-card {
    background: white;
    border-radius: var(--border-radius);
    display: flex;
    gap: 20px;
    padding: 25px;
    transition: var(--transition);
    box-shadow: var(--shadow);
}

.news-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-hover);
}

.news-date {
    text-align: center;
    padding: 10px 15px;
    background: var(--primary-color);
    border-radius: var(--border-radius);
    color: white;
    min-width: 70px;
}

.news-date .day {
    display: block;
    font-size: 24px;
    font-weight: 700;
}

.news-date .month {
    font-size: 12px;
    text-transform: uppercase;
}

.news-content h3 {
    font-size: 16px;
    color: var(--text-color);
    margin-bottom: 10px;
    line-height: 1.4;
}

.news-content p {
    font-size: 13px;
    color: var(--text-light);
    margin-bottom: 15px;
    line-height: 1.6;
}

.read-more {
    font-size: 13px;
    color: var(--primary-color);
    font-weight: 600;
}

.read-more:hover {
    color: var(--primary-dark);
}

.read-more i {
    margin-left: 5px;
}

/* ===== 联系我们区域 ===== */
.contact-section {
    padding: 100px 0;
    background: white;
}

.contact-content {
    display: grid;
    grid-template-columns: 1fr 1.2fr;
    gap: 60px;
}

.contact-info {
    padding: 40px;
    background: var(--bg-dark);
    border-radius: var(--border-radius);
}

.info-item {
    display: flex;
    gap: 20px;
    margin-bottom: 30px;
    color: white;
}

.info-item i {
    font-size: 24px;
    color: var(--secondary-color);
}

.info-item h4 {
    font-size: 16px;
    margin-bottom: 5px;
}

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

.social-links {
    display: flex;
    gap: 15px;
    margin-top: 30px;
}

.social-link {
    width: 45px;
    height: 45px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 50%;
    display: flex;
    justify-content: center;
    align-items: center;
    color: white;
    font-size: 18px;
    transition: var(--transition);
}

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

.contact-form {
    padding: 40px;
    background: var(--bg-light);
    border-radius: var(--border-radius);
}

.form-group {
    margin-bottom: 20px;
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 15px;
    border: 2px solid var(--border-color);
    border-radius: var(--border-radius);
    font-size: 14px;
    transition: var(--transition);
    font-family: inherit;
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary-color);
}

.form-group textarea {
    resize: vertical;
    min-height: 120px;
}

/* ===== 页脚 ===== */
.footer {
    background: var(--bg-dark);
    padding: 60px 0 30px;
    color: white;
}

.footer-content {
    display: grid;
    grid-template-columns: 1.5fr 1fr 1fr 1.2fr;
    gap: 40px;
    margin-bottom: 40px;
}

.footer-section h3 {
    font-size: 28px;
    margin-bottom: 15px;
    color: var(--secondary-color);
}

.footer-section h4 {
    font-size: 18px;
    margin-bottom: 20px;
    color: white;
}

.footer-section p {
    font-size: 14px;
    color: rgba(255, 255, 255, 0.7);
    line-height: 1.8;
}

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

.footer-section ul li a {
    font-size: 14px;
    color: rgba(255, 255, 255, 0.7);
}

.footer-section ul li a:hover {
    color: var(--secondary-color);
}

.footer-section i {
    margin-right: 10px;
    color: var(--secondary-color);
}

.footer-bottom {
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    padding-top: 30px;
    text-align: center;
}

.footer-bottom p {
    font-size: 14px;
    color: rgba(255, 255, 255, 0.5);
}

/* ===== 返回顶部按钮 ===== */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: 50%;
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 20px;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transition: var(--transition);
    box-shadow: var(--shadow);
    z-index: 999;
}

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

.back-to-top:hover {
    background: var(--primary-dark);
    transform: translateY(-3px);
}

/* ===== 动画关键帧 ===== */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes pulse {
    0%, 100% {
        transform: scale(1);
    }
    50% {
        transform: scale(1.05);
    }
}

/* ===== 响应式设计 ===== */
@media (max-width: 1200px) {
    .stats-grid {
        grid-template-columns: repeat(3, 1fr);
    }
    
    .partners-grid {
        grid-template-columns: repeat(3, 1fr);
    }
}

@media (max-width: 992px) {
    .about-content {
        grid-template-columns: 1fr;
    }
    
    .about-image {
        order: -1;
    }
    
    .tech-grid,
    .products-grid,
    .news-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .applications-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .footer-content {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .contact-content {
        grid-template-columns: 1fr;
    }
    
    .metrics-content {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .series-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .equipment-grid {
        grid-template-columns: 1fr;
    }
    
    .footer {
        padding: 50px 0 25px;
    }
    
    .footer-content {
        gap: 30px;
    }
}

@media (max-width: 768px) {
    .main-nav {
        position: fixed;
        top: 70px;
        left: 0;
        right: 0;
        background: white;
        padding: 20px;
        transform: translateY(-100%);
        opacity: 0;
        visibility: hidden;
        transition: var(--transition);
        box-shadow: var(--shadow);
    }
    
    .main-nav.active {
        transform: translateY(0);
        opacity: 1;
        visibility: visible;
    }
    
    .nav-list {
        flex-direction: column;
        gap: 15px;
    }
    
    .mobile-menu-btn {
        display: block;
    }
    
    .slide-title {
        font-size: 32px;
    }
    
    .slide-subtitle {
        font-size: 18px;
    }
    
    .stats-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 20px;
    }
    
    .stat-number {
        font-size: 36px;
    }
    
    .section-title {
        font-size: 28px;
    }
    
    .tech-grid,
    .products-grid,
    .cases-grid,
    .news-grid {
        grid-template-columns: 1fr;
    }
    
    .applications-grid {
        grid-template-columns: 1fr;
    }
    
    .partners-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .footer-content {
        grid-template-columns: 1fr;
        text-align: center;
    }
    
    .about-features {
        grid-template-columns: 1fr;
    }
    
    .specs-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .series-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .equipment-grid {
        grid-template-columns: 1fr;
    }
    
    .metrics-content {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 15px;
    }
    
    .stats-grid {
        grid-template-columns: 1fr;
    }
    
    .stat-item {
        padding: 15px;
    }
    
    .partners-grid {
        grid-template-columns: 1fr;
    }
    
    .specs-grid {
        grid-template-columns: 1fr;
    }
    
    .series-grid {
        grid-template-columns: 1fr;
    }
    
    .metrics-content {
        grid-template-columns: 1fr;
    }
    
    .metric-header {
        flex-direction: column;
        align-items: flex-start;
        gap: 5px;
    }
}