/* ==========================================
   全局基础样式 (Global)
========================================== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Helvetica Neue', 'PingFang SC', 'Microsoft YaHei', sans-serif;
    color: #1a1a1a;
    background: #fff;
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
}

.container {
    max-width: 1440px;
    margin: 0 auto;
    padding: 0 60px;
}

/* ==========================================
   导航栏样式 (Header)
========================================== */
.header {
    position: fixed;
    top: 0;
    width: 100%;
    background: #fff;
    z-index: 1000;
    border-bottom: 1px solid #f0f0f0;
}

/* 右侧菜单+语言容器 */
.nav-right {
    display: flex;
    align-items: center;
    gap: 50px; /* 菜单和语言按钮之间的距离 */
}

/* 语言切换样式 */
.lang-switch {
    display: flex;
    align-items: center;
    gap: 12px;
    font-size: 13px;
    padding-left: 30px;
    border-left: 1px solid #eee; /* 左侧加一条细线和主菜单隔开 */
}

.lang-switch a {
    color: #999;
    text-decoration: none;
    transition: color 0.3s;
}

.lang-switch a:hover,
.lang-switch a.active {
    color: #1a1a1a;
    font-weight: bold;
}

.lang-switch .divider {
    color: #ddd;
    font-size: 10px;
}

.nav {
    background: #fff;
}

.nav-inner {
    max-width: 1600px; /* 菜单拉宽 */
    margin: 0 auto;
    padding: 0 40px; /* 减少留白，Logo靠左 */
    height: 100px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

/* ==========================================
   图文组合式 Logo 样式
========================================== */
.logo-link {
    display: flex;
    align-items: center; 
    gap: 0px; /* 图文间距*/
    text-decoration: none;
    white-space: nowrap; 
}

.nav-logo-icon {
    height: 76px; /* logo大小 */
    width: auto;
    display: block;
    object-fit: contain; 
}

.logo-text-box {
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: flex-start; 
}

.logo-cn {
    font-size: 28px; /* 字号 */
    font-weight: 900; /* 加粗900 */
    color: #1a1a1a; 
    letter-spacing: 2px; /* 字间距 */
    line-height: 1; 
    font-family:  sans-serif; 
}

.logo-en {
    font-size: 10px; 
    color: #666; 
    letter-spacing: 0; /* 英文间距收紧 */
    font-family: 'Roboto', Arial, Helvetica, sans-serif; 
    font-weight: 700; /* 英文加粗 */
    margin-top: 4px; /* 英文紧贴在中文下方 */
    line-height: 1;
    text-transform: uppercase; 
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 45px;
}

.nav-menu a {
    text-decoration: none;
    color: #333; 
    font-size: 15px;
    font-weight: 500; 
    letter-spacing: 0.5px;
    position: relative;
    padding: 10px 0; /* 增加上下可点击区域 */
    transition: all 0.3s;
}

/* 下划线初始状态：放在正中间，缩放比例为 0 */
.nav-menu a:after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    width: 100%;
    height: 2px;
    background: #1a1a1a;
    transform: translateX(-50%) scaleX(0); /*  scaleX 缩放 */
    transform-origin: center; /* 动画从中心点向两边展开 */
    transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1); /* 缓动曲线 */
}

/* 鼠标悬浮 或 处于当前页面时，下划线展开到 100% 不溢出 */
.nav-menu a:hover:after, 
.nav-menu a.active:after {
    transform: translateX(-50%) scaleX(1);
}

/* 当前页面的字体加粗 */
.nav-menu a.active {
    font-weight: 600; 
}

/* 搜索 + 按钮 */
.nav-actions {
    display: flex;
    align-items: center;
    gap: 25px;
    padding-left: 30px;
    border-left: 1px solid #e0e0e0; /* 分割线 */
}

/* 搜索图标交互效果 */
.search-icon {
    color: #1a1a1a;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: transform 0.3s, color 0.3s;
}

.search-icon:hover {
    color: #666;
    transform: scale(1.1); /* 鼠标放上去放大 */
}

/* 导航栏专属 CTA 按钮 */
.nav-btn {
    display: inline-block;
    background: #1a1a1a;
    color: #fff !important;
    padding: 12px 24px;
    font-size: 14px;
    font-weight: 500;
    letter-spacing: 1px;
    text-decoration: none;
    border-radius: 2px; /* 工业风微圆角 */
    transition: all 0.3s ease;
}

.nav-btn:hover {
    background: #333;
    box-shadow: 0 4px 12px rgba(0,0,0,0.15);
    transform: translateY(-2px); /* 鼠标放上去有悬浮 */
}


/* ==========================================
   底部样式 (Footer)
========================================== */
.footer {
    background: #0a0a0a;
    color: white;
    padding: 80px 0 30px;
}

.footer-content {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: 80px;
    margin-bottom: 60px;
}

.footer-brand h3 {
    font-size: 24px;
    font-weight: 300;
    letter-spacing: 2px;
    margin-bottom: 20px;
}

.footer-desc {
    font-size: 14px;
    color: #888;
    line-height: 1.8;
    margin-bottom: 30px;
}

.footer-column h4 {
    font-size: 13px;
    letter-spacing: 1px;
    margin-bottom: 25px;
    font-weight: 400;
    color: #aaa;
}

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

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

.footer-column a {
    color: #666;
    text-decoration: none;
    font-size: 14px;
    transition: color 0.3s;
}

.footer-column a:hover {
    color: white;
}

.footer-bottom {
    padding-top: 30px;
    border-top: 1px solid #222;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.footer-copyright {
    font-size: 13px;
    color: #666;
}

.footer-links {
    display: flex;
    gap: 30px;
}

.footer-links a {
    color: #666;
    text-decoration: none;
    font-size: 13px;
    transition: color 0.3s;
}

.footer-links a:hover {
    color: #888;
}