* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Microsoft YaHei', 'Segoe UI', Arial, sans-serif;
}

:root {
    --primary-color: #1a56a8;
    --primary-dark: #0e3a7a;
    --light-bg: #f5f8fd;
    --text-dark: #333;
    --text-light: #666;
    --white: #ffffff;
}

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

/* 顶部导航栏 */
.top-bar {
    background-color: var(--white);
    padding: 10px 40px;
    display: flex;
    justify-content: flex-end;
    align-items: center;
    border-bottom: 1px solid #eee;
    font-size: 14px;
}

.language-switcher {
    margin-right: 20px;
    display: flex;
    align-items: center;
}

.language-switcher select {
    border: 1px solid #ddd;
    padding: 5px 10px;
    border-radius: 4px;
    background-color: #f9f9f9;
    cursor: pointer;
}

.search-container {
    display: flex;
    align-items: center;
}

.search-container input {
    padding: 6px 12px;
    border: 1px solid #ddd;
    border-radius: 4px 0 0 4px;
    outline: none;
    width: 200px;
}

.search-container button {
    background-color: var(--primary-color);
    color: white;
    border: none;
    padding: 7px 15px;
    border-radius: 0 4px 4px 0;
    cursor: pointer;
}

/* 主导航栏 */
.main-nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0 40px;
    background-color: var(--white);
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
    position: relative;
    z-index: 100;
}

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

.logo-icon {
    font-size: 28px;
    color: var(--primary-color);
    margin-right: 12px;
}

.logo-text {
    font-size: 28px;
    font-weight: bold;
    color: var(--primary-color);
    letter-spacing: 2px;
}

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

.nav-item {
    position: relative;
}

.nav-link {
    display: block;
    padding: 25px 20px;
    color: var(--text-dark);
    text-decoration: none;
    font-size: 16px;
    font-weight: 500;
    transition: all 0.3s ease;
}

.nav-link:hover {
    color: var(--primary-color);
    background-color: var(--light-bg);
}

.dropdown-menu {
    position: absolute;
    top: 100%;
    left: 0;
    background-color: var(--white);
    min-width: 200px;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
    opacity: 0;
    visibility: hidden;
    transform: translateY(10px);
    transition: all 0.3s ease;
    z-index: 1000;
}

.nav-item:hover .dropdown-menu {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.dropdown-menu li {
    list-style: none;
    border-bottom: 1px solid #eee;
}

.dropdown-menu li:last-child {
    border-bottom: none;
}

.dropdown-menu a {
    display: block;
    padding: 12px 20px;
    color: var(--text-dark);
    text-decoration: none;
    transition: all 0.3s ease;
}

.dropdown-menu a:hover {
    background-color: var(--light-bg);
    color: var(--primary-color);
    padding-left: 25px;
}

/* 主体内容区域 - 双背景设计 */
.main-content {
    position: relative;
    min-height: calc(100vh - 150px);
}

.bg-section {
    position: relative;
    padding: 100px 40px;
    display: flex;
    align-items: center;
}

.bg-top {
    background: linear-gradient(135deg, #e8f1ff 0%, #d6e6ff 100%);
    min-height: 60vh;
    background-image: url('/images/iot1.png');
    background-size: cover;
    background-position: center;
    background-blend-mode: overlay;
}

.bg-bottom {
    background: linear-gradient(135deg, #0e3a7a 0%, #1a56a8 100%);
    min-height: 40vh;
    background-image: url('/images/database.png');
    background-size: cover;
    background-position: center;
    background-blend-mode: overlay;
    color: white;
}

.hero-content {
    max-width: 600px;
}

.hero-title {
    font-size: 48px;
    font-weight: bold;
    margin-bottom: 20px;
    line-height: 1.2;
    color: var(--primary-dark);
}

.hero-subtitle {
    font-size: 20px;
    color:  #bec4ce;
    margin-bottom: 30px;
}

.cta-button {
    display: inline-block;
    background-color: var(--primary-color);
    color: white;
    padding: 14px 30px;
    text-decoration: none;
    border-radius: 4px;
    font-weight: 500;
    font-size: 16px;
    transition: all 0.3s ease;
    border: none;
    cursor: pointer;
}

.cta-button:hover {
    background-color: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
}

.bottom-content {
    max-width: 800px;
    margin: 0 auto;
    text-align: center;
}

.bottom-title {
    font-size: 36px;
    font-weight: bold;
    margin-bottom: 20px;
}

.bottom-text {
    font-size: 18px;
    line-height: 1.8;
    opacity: 0.9;
}

/* 页脚 */
.footer {
    background-color: #0a2a5a;
    color: #ccc;
    padding: 40px;
    text-align: center;
}

.footer-links {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    margin-bottom: 20px;
}

.footer-links a {
    color: #ccc;
    text-decoration: none;
    margin: 0 15px;
    margin-bottom: 10px;
    transition: color 0.3s ease;
}

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

.copyright {
    font-size: 14px;
    color: #999;
    margin-top: 20px;
}

/* 响应式设计 */
@media (max-width: 992px) {
    .main-nav {
        flex-direction: column;
        padding: 15px 20px;
    }
    
    .nav-menu {
        margin-top: 20px;
        width: 100%;
        justify-content: center;
        flex-wrap: wrap;
    }
    
    .nav-link {
        padding: 15px 15px;
    }
    
    .hero-title {
        font-size: 36px;
    }
    
    .hero-subtitle {
        font-size: 18px;
    }
}

@media (max-width: 768px) {
    .top-bar {
        padding: 10px 20px;
        flex-direction: column;
        align-items: flex-start;
    }
    
    .language-switcher {
        margin-bottom: 10px;
    }
    
    .search-container input {
        width: 150px;
    }
    
    .bg-section {
        padding: 60px 20px;
    }
    
    .footer-links {
        flex-direction: column;
    }
    
    .footer-links a {
        margin: 5px 0;
    }

}