/* ==========================================
   全局样式和变量
   ========================================== */
:root {
    /* Caterpillar 风格配色 */
    --primary-color: #FFCB05;      /* 卡特彼勒黄色 */
    --primary-dark: #E6B800;
    --secondary-color: #1A1A1A;    /* 深黑色 */
    --text-dark: #1A1A1A;
    --text-light: #666666;
    --bg-light: #F5F5F5;
    --bg-white: #FFFFFF;
    --border-color: #E0E0E0;
    
    /* 字体 */
    --font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Microsoft YaHei', 'PingFang SC', 'Hiragino Sans GB', 'SimSun', sans-serif;
    
    /* 阴影 */
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.08);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.12);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.16);
    
    /* 动画 */
    --transition: all 0.3s ease;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-family);
    color: var(--text-dark);
    line-height: 1.6;
    overflow-x: hidden;
}

.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 20px;
}

/* ==========================================
   导航栏
   ========================================== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: var(--bg-white);
    box-shadow: var(--shadow-sm);
    z-index: 1000;
    transition: var(--transition);
}

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

.nav-wrapper {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1.2rem 0;
    min-height: 70px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-size: 2.4rem;
    font-weight: 700;
    color: var(--secondary-color);
    text-decoration: none;
    transition: var(--transition);
}

.logo:hover {
    opacity: 0.8;
}

.logo-image {
    height: 45px;
    width: auto;
    object-fit: contain;
}

.logo-text {
    display: flex;
    align-items: baseline;
    gap: 0.5rem;
}

.logo-sub {
    font-size: 0.8rem;
    font-weight: 400;
    color: var(--text-light);
}

.nav-menu {
    display: flex;
    align-items: center;
    list-style: none;
    gap: 2rem;
}

.nav-menu li {
    display: flex;
    align-items: center;
}

.nav-menu li a {
    color: var(--text-dark);
    text-decoration: none;
    font-weight: 500;
    font-size: 1.1rem;
    transition: var(--transition);
    position: relative;
    padding: 0.5rem 0;
    display: flex;
    align-items: center;
}

.nav-menu li a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 3px;
    background: var(--primary-color);
    transition: var(--transition);
}

.nav-menu li a:hover::after,
.nav-menu li a.active::after {
    width: 100%;
}

.nav-menu li a:hover,
.nav-menu li a.active {
    color: var(--primary-color);
}

/* 语言切换器 - 下拉菜单 */
.language-switcher {
    position: relative;
    margin-left: 1.5rem;
}

/* 移动端语言切换器 - 默认隐藏 */
.language-switcher.mobile {
    display: none;
}

/* 桌面端语言切换器 */
.language-switcher.desktop {
    display: block;
}

/* 移动端菜单内的语言切换器 */
.mobile-lang-switcher {
    margin-top: 1.5rem;
    padding-top: 1.5rem;
    border-top: 1px solid var(--border-color);
}

.mobile-lang-switcher .language-switcher {
    margin-left: 0;
    width: 100%;
}

.lang-dropdown-btn {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.6rem 1rem;
    background: var(--bg-white);
    border: 2px solid var(--border-color);
    border-radius: 4px;
    color: var(--text-dark);
    font-weight: 500;
    font-size: 1rem;
    cursor: pointer;
    transition: var(--transition);
    min-width: 110px;
}

.lang-dropdown-btn:hover {
    border-color: var(--primary-color);
    color: var(--primary-color);
}

.language-switcher.active .lang-dropdown-btn {
    border-color: var(--primary-color);
    background: var(--bg-light);
}

.current-lang {
    flex: 1;
    text-align: left;
}

.dropdown-arrow {
    transition: var(--transition);
    color: var(--text-dark);
}

.language-switcher.active .dropdown-arrow {
    transform: rotate(180deg);
    color: var(--primary-color);
}

.lang-dropdown-menu {
    position: absolute;
    top: calc(100% + 0.5rem);
    right: 0;
    min-width: 180px;
    background: var(--bg-white);
    border: 2px solid var(--primary-color);
    border-radius: 4px;
    box-shadow: var(--shadow-lg);
    opacity: 0;
    visibility: hidden;
    transform: translateY(-10px);
    transition: var(--transition);
    z-index: 1000;
}

.language-switcher.active .lang-dropdown-menu {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.lang-option {
    width: 100%;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0.75rem 1rem;
    background: transparent;
    border: none;
    color: var(--text-dark);
    font-size: 0.9rem;
    cursor: pointer;
    transition: var(--transition);
    text-align: left;
}

.lang-option:not(:last-child) {
    border-bottom: 1px solid var(--border-color);
}

.lang-option:hover {
    background: var(--bg-light);
    color: var(--primary-color);
}

.lang-option.active {
    background: rgba(255, 203, 5, 0.1);
    color: var(--primary-color);
    font-weight: 600;
}

.lang-option .lang-name {
    font-weight: 500;
}

.lang-option .lang-name-en {
    font-size: 0.85rem;
    color: var(--text-light);
}

.lang-option.active .lang-name-en {
    color: var(--primary-color);
}

.mobile-menu-toggle {
    display: none;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 0.5rem;
    width: 44px;
    height: 44px;
    position: relative;
}

.mobile-menu-toggle span {
    width: 26px;
    height: 3px;
    background: var(--secondary-color);
    transition: all 0.3s ease;
    display: block;
    border-radius: 2px;
    position: relative;
}

.mobile-menu-toggle:hover span {
    background: var(--primary-color);
}

.mobile-menu-toggle.active span {
    background: var(--secondary-color);
}

/* ==========================================
   英雄区域轮播图
   ========================================== */
.hero-slider {
    position: relative;
    height: 100vh;
    min-height: 600px;
    color: var(--bg-white);
    overflow: hidden;
}

/* 顶部装饰横线 */
.hero-top-lines {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 100;
    display: flex;
    flex-direction: column;
}

.hero-top-lines .line {
    width: 100%;
    height: 4px;
}

.hero-top-lines .line-yellow {
    background: var(--primary-color);
    height: 5px;
}

.hero-top-lines .line-black {
    background: var(--secondary-color);
    height: 3px;
}

.hero-top-lines .line-gray {
    background: rgba(255, 255, 255, 0.2);
    height: 2px;
}

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

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

.slide.active {
    opacity: 1;
    visibility: visible;
    z-index: 1;
}

.slide-background {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 0;
}

.slide-background::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: 
        repeating-linear-gradient(
            45deg,
            transparent,
            transparent 10px,
            rgba(255, 203, 5, 0.03) 10px,
            rgba(255, 203, 5, 0.03) 20px
        );
}

.hero-content {
    position: relative;
    z-index: 2;
    max-width: 900px;
    padding: 2rem;
    animation: fadeInUp 1s ease;
}

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

.hero-title {
    font-size: 4rem;
    font-weight: 900;
    margin-bottom: 1rem;
    letter-spacing: -1px;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.3);
}

.hero-subtitle {
    font-size: 1.8rem;
    font-weight: 500;
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.hero-description {
    font-size: 1.2rem;
    margin-bottom: 2.5rem;
    opacity: 0.9;
}

.hero-buttons {
    display: flex;
    gap: 1.5rem;
    justify-content: center;
    flex-wrap: wrap;
}

/* ==========================================
   按钮
   ========================================== */
.btn {
    display: inline-block;
    padding: 1rem 2.5rem;
    font-size: 1rem;
    font-weight: 600;
    text-decoration: none;
    border-radius: 4px;
    transition: var(--transition);
    cursor: pointer;
    border: 2px solid transparent;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

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

.btn-primary:hover {
    background: var(--primary-dark);
    border-color: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.btn-secondary {
    background: transparent;
    color: var(--bg-white);
    border-color: var(--bg-white);
}

.btn-secondary:hover {
    background: var(--bg-white);
    color: var(--secondary-color);
    transform: translateY(-2px);
}

.btn-full {
    width: 100%;
}

/* ==========================================
   轮播控制按钮
   ========================================== */
.slider-control {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    z-index: 10;
    background: rgba(255, 203, 5, 0.9);
    color: var(--secondary-color);
    border: none;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
}

.slider-control:hover {
    background: var(--primary-color);
    transform: translateY(-50%) scale(1.1);
    box-shadow: 0 6px 20px rgba(0, 0, 0, 0.4);
}

.slider-control.prev {
    left: 2rem;
}

.slider-control.next {
    right: 2rem;
}

.slider-control svg {
    width: 24px;
    height: 24px;
}

/* ==========================================
   轮播指示器
   ========================================== */
.slider-indicators {
    position: absolute;
    bottom: 5rem;
    left: 50%;
    transform: translateX(-50%);
    z-index: 10;
    display: flex;
    gap: 1rem;
}

.indicator {
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.5);
    border: 2px solid var(--bg-white);
    cursor: pointer;
    transition: var(--transition);
    padding: 0;
}

.indicator:hover {
    background: rgba(255, 203, 5, 0.8);
    transform: scale(1.2);
}

.indicator.active {
    background: var(--primary-color);
    width: 40px;
    border-radius: 6px;
}

/* ==========================================
   滚动指示器
   ========================================== */
.scroll-indicator {
    position: absolute;
    bottom: 2rem;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.5rem;
    color: var(--bg-white);
    opacity: 0.7;
    animation: bounce 2s infinite;
}

@keyframes bounce {
    0%, 20%, 50%, 80%, 100% {
        transform: translateX(-50%) translateY(0);
    }
    40% {
        transform: translateX(-50%) translateY(-10px);
    }
    60% {
        transform: translateX(-50%) translateY(-5px);
    }
}

.scroll-arrow {
    width: 24px;
    height: 24px;
    border-left: 2px solid currentColor;
    border-bottom: 2px solid currentColor;
    transform: rotate(-45deg);
}

/* ==========================================
   通用区块样式
   ========================================== */
section {
    padding: 6rem 0;
}

.section-header {
    text-align: center;
    margin-bottom: 4rem;
}

.section-title {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    color: var(--secondary-color);
}

.title-underline {
    width: 80px;
    height: 4px;
    background: var(--primary-color);
    margin: 0 auto 1.5rem;
}

.section-subtitle {
    font-size: 1.1rem;
    color: var(--text-light);
    max-width: 600px;
    margin: 0 auto;
}

/* ==========================================
   关于我们
   ========================================== */
.about-section {
    background: var(--bg-white);
}

.about-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
}

.about-text h3 {
    font-size: 1.8rem;
    margin-bottom: 1.5rem;
    color: var(--secondary-color);
}

.about-text p {
    margin-bottom: 1.5rem;
    color: var(--text-light);
    font-size: 1.05rem;
    line-height: 1.8;
}

.about-stats {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 2rem;
    margin-top: 3rem;
}

.stat-item {
    text-align: center;
    padding: 1.5rem;
    background: var(--bg-light);
    border-radius: 8px;
    transition: var(--transition);
}

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

.stat-number {
    font-size: 2.5rem;
    font-weight: 900;
    color: var(--primary-color);
    margin-bottom: 0.5rem;
}

.stat-label {
    font-size: 0.9rem;
    color: var(--text-light);
}

.about-image {
    position: relative;
}

.image-placeholder {
    width: 100%;
    border-radius: 8px;
    overflow: hidden;
    box-shadow: var(--shadow-lg);
}

.image-placeholder svg {
    width: 100%;
    height: auto;
    display: block;
}

.about-img {
    width: 100%;
    height: auto;
    border-radius: 8px;
    box-shadow: var(--shadow-lg);
    display: block;
    object-fit: cover;
    transition: var(--transition);
}

.about-img:hover {
    transform: scale(1.02);
    box-shadow: 0 12px 40px rgba(0, 0, 0, 0.2);
}

/* ==========================================
   产品服务
   ========================================== */
.products-section {
    background: var(--bg-light);
}

.products-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
}

.product-card {
    background: var(--bg-white);
    padding: 2.5rem;
    border-radius: 8px;
    text-align: center;
    transition: var(--transition);
    border: 2px solid transparent;
}

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

.product-icon {
    width: 80px;
    height: 80px;
    margin: 0 auto 1.5rem;
    color: var(--primary-color);
    transition: var(--transition);
}

.product-card:hover .product-icon {
    transform: scale(1.1) rotate(5deg);
}

.product-image {
    width: 100%;
    height: 200px;
    margin-bottom: 1.5rem;
    overflow: hidden;
    border-radius: 8px;
    background: var(--bg-light);
}

.product-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: var(--transition);
}

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

.product-card h3 {
    font-size: 1.4rem;
    margin-bottom: 1rem;
    color: var(--secondary-color);
}

.product-card p {
    color: var(--text-light);
    line-height: 1.7;
}

/* ==========================================
   核心能力
   ========================================== */
.capabilities-section {
    background: var(--secondary-color);
    color: var(--bg-white);
}

.capabilities-section .section-title {
    color: var(--bg-white);
}

.capabilities-section .title-underline {
    background: var(--primary-color);
}

.capabilities-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
}

.capability-item {
    padding: 2rem;
    background: rgba(255, 255, 255, 0.05);
    border-radius: 8px;
    border-left: 4px solid var(--primary-color);
    transition: var(--transition);
}

.capability-item:hover {
    background: rgba(255, 255, 255, 0.1);
    transform: translateX(10px);
}

.capability-number {
    font-size: 3rem;
    font-weight: 900;
    color: var(--primary-color);
    opacity: 0.3;
    margin-bottom: 1rem;
    line-height: 1;
}

.capability-item h3 {
    font-size: 1.3rem;
    margin-bottom: 1rem;
    color: var(--primary-color);
}

.capability-item p {
    color: rgba(255, 255, 255, 0.8);
    line-height: 1.7;
}

/* ==========================================
   设备展示
   ========================================== */
.equipment-section {
    background: var(--bg-white);
}

.equipment-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
}

.equipment-card {
    background: var(--bg-white);
    border-radius: 8px;
    overflow: hidden;
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
}

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

.equipment-image {
    position: relative;
    overflow: hidden;
    background: var(--bg-light);
    height: 250px;
}

.equipment-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: block;
    transition: var(--transition);
}

.equipment-card:hover .equipment-image img {
    transform: scale(1.05);
}

.equipment-image::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(to top, rgba(0, 0, 0, 0.3), transparent);
    opacity: 0;
    transition: var(--transition);
}

.equipment-card:hover .equipment-image::after {
    opacity: 1;
}

.equipment-info {
    padding: 1.5rem;
}

.equipment-info h3 {
    font-size: 1.3rem;
    margin-bottom: 0.75rem;
    color: var(--secondary-color);
}

.equipment-info p {
    color: var(--text-light);
    font-size: 0.95rem;
    line-height: 1.6;
}

/* ==========================================
   联系我们
   ========================================== */
.contact-section {
    background: var(--bg-light);
}

.contact-content {
    display: grid;
    grid-template-columns: 1fr 1.5fr;
    gap: 4rem;
}

.contact-info {
    display: flex;
    flex-direction: column;
    gap: 2rem;
}

.contact-item {
    display: flex;
    gap: 1.5rem;
    align-items: flex-start;
    padding: 1.5rem;
    background: var(--bg-white);
    border-radius: 8px;
    transition: var(--transition);
}

.contact-item:hover {
    box-shadow: var(--shadow-md);
    transform: translateX(10px);
}

.contact-icon {
    width: 50px;
    height: 50px;
    min-width: 50px;
    background: var(--primary-color);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--secondary-color);
}

.contact-icon svg {
    width: 24px;
    height: 24px;
}

.contact-item h3 {
    font-size: 1.1rem;
    margin-bottom: 0.5rem;
    color: var(--secondary-color);
}

.contact-item p {
    color: var(--text-light);
    font-size: 0.95rem;
}

.contact-form {
    background: var(--bg-white);
    padding: 2.5rem;
    border-radius: 8px;
    box-shadow: var(--shadow-sm);
}

.form-group {
    margin-bottom: 1.5rem;
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 1rem;
    border: 2px solid var(--border-color);
    border-radius: 4px;
    font-family: var(--font-family);
    font-size: 1rem;
    transition: var(--transition);
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(255, 203, 5, 0.1);
}

.form-group textarea {
    resize: vertical;
    min-height: 150px;
}

/* ==========================================
   页脚
   ========================================== */
.footer {
    background: var(--secondary-color);
    color: var(--bg-white);
    padding: 3rem 0 1.5rem;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 3rem;
    margin-bottom: 2rem;
}

.footer-col h4 {
    font-size: 1.2rem;
    margin-bottom: 1rem;
    color: var(--primary-color);
}

.footer-col p {
    color: rgba(255, 255, 255, 0.7);
    line-height: 1.7;
}

.footer-col ul {
    list-style: none;
}

.footer-col ul li {
    margin-bottom: 0.75rem;
}

.footer-col ul li a {
    color: rgba(255, 255, 255, 0.7);
    text-decoration: none;
    transition: var(--transition);
}

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

.footer-bottom {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    color: rgba(255, 255, 255, 0.5);
}

/* ==========================================
   响应式设计
   ========================================== */
@media (max-width: 968px) {
    .hero-title {
        font-size: 3rem;
    }
    
    .hero-subtitle {
        font-size: 1.5rem;
    }
    
    .about-content,
    .contact-content {
        grid-template-columns: 1fr;
        gap: 2rem;
    }
    
    .about-stats {
        grid-template-columns: repeat(3, 1fr);
        gap: 1rem;
    }
}

@media (max-width: 768px) {
    .logo {
        font-size: 2.0rem;
    }
    
    .logo-image {
        height: 40px;
    }
    
    .nav-menu {
        position: fixed;
        top: 70px;
        left: 0;
        right: 0;
        background: var(--bg-white);
        flex-direction: column;
        padding: 2rem;
        box-shadow: var(--shadow-md);
        transform: translateY(-100%);
        opacity: 0;
        visibility: hidden;
        transition: var(--transition);
    }
    
    /* 移动端隐藏桌面端语言切换器 */
    .language-switcher.desktop {
        display: none;
    }
    
    /* 移动端显示菜单内的语言切换器 */
    .language-switcher.mobile {
        display: block;
    }
    
    /* 移动端菜单内语言切换器样式 */
    .mobile-lang-switcher {
        list-style: none;
        margin: 0;
        padding: 0;
    }
    
    .mobile-lang-switcher .lang-dropdown-btn {
        width: 100%;
        padding: 0.75rem 1rem;
        font-size: 0.9rem;
        justify-content: space-between;
        border: 1px solid var(--border-color);
    }
    
    .mobile-lang-switcher .language-switcher.active .lang-dropdown-btn {
        border-color: var(--primary-color);
        background: var(--bg-light);
    }
    
    .mobile-lang-switcher .lang-dropdown-menu {
        position: static;
        width: 100%;
        margin-top: 0.5rem;
        box-shadow: none;
        border: 1px solid var(--border-color);
        border-top: none;
        opacity: 0;
        visibility: hidden;
        transform: translateY(-10px);
        transition: var(--transition);
        max-height: 0;
        overflow: hidden;
    }
    
    .mobile-lang-switcher .language-switcher.active .lang-dropdown-menu {
        opacity: 1;
        visibility: visible;
        transform: translateY(0);
        max-height: 300px;
    }
    
    .mobile-lang-switcher .lang-option {
        padding: 0.75rem 1rem;
        font-size: 0.9rem;
    }
    
    .mobile-lang-switcher .lang-option .lang-name-en {
        font-size: 0.85rem;
    }
    
    .nav-menu.active {
        transform: translateY(0);
        opacity: 1;
        visibility: visible;
    }
    
    .mobile-menu-toggle {
        display: flex;
        gap: 6px;
    }
    
    .mobile-menu-toggle.active span:nth-child(1) {
        position: absolute;
        top: 50%;
        left: 50%;
        transform: translate(-50%, -50%) rotate(45deg);
    }
    
    .mobile-menu-toggle.active span:nth-child(2) {
        opacity: 0;
        transform: scale(0);
    }
    
    .mobile-menu-toggle.active span:nth-child(3) {
        position: absolute;
        top: 50%;
        left: 50%;
        transform: translate(-50%, -50%) rotate(-45deg);
    }
    
    .slider-control {
        width: 40px;
        height: 40px;
    }
    
    .slider-control.prev {
        left: 1rem;
    }
    
    .slider-control.next {
        right: 1rem;
    }
    
    .slider-indicators {
        bottom: 4rem;
    }
    
    .hero-title {
        font-size: 2.5rem;
    }
    
    .hero-subtitle {
        font-size: 1.3rem;
    }
    
    .hero-description {
        font-size: 1rem;
    }
    
    .hero-buttons {
        flex-direction: column;
    }
    
    .section-title {
        font-size: 2rem;
    }
    
    section {
        padding: 4rem 0;
    }
    
    .about-stats {
        grid-template-columns: 1fr;
    }
    
    .capabilities-grid {
        grid-template-columns: 1fr;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
        gap: 2rem;
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: 2rem;
    }
    
    .logo {
        font-size: 1.6rem;
    }
    
    .logo-image {
        height: 35px;
    }
    
    .btn {
        padding: 0.875rem 2rem;
        font-size: 0.9rem;
    }
    
    .product-card,
    .contact-form {
        padding: 1.5rem;
    }
}

/* ==========================================
   动画和过渡效果
   ========================================== */
@keyframes fadeIn {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

.fade-in {
    animation: fadeIn 0.6s ease;
}

/* 页面加载动画 */
.animate-on-scroll {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

.animate-on-scroll.visible {
    opacity: 1;
    transform: translateY(0);
}

/* 工具类 */
.text-center {
    text-align: center;
}

.mt-1 { margin-top: 1rem; }
.mt-2 { margin-top: 2rem; }
.mt-3 { margin-top: 3rem; }
.mb-1 { margin-bottom: 1rem; }
.mb-2 { margin-bottom: 2rem; }
.mb-3 { margin-bottom: 3rem; }