/* 通用样式 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Open Sans', sans-serif;
}

body {
    line-height: 1.6;
    color: #333;
}

a {
    text-decoration: none;
    color: inherit;
}

ul {
    list-style: none;
}

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

/* 导航栏 */
header {
    background-color: #fff;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    position: sticky;
    top: 0;
    z-index: 100;
}

.nav-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    max-width: 1200px;
    margin: 0 auto;
    padding: 15px 20px;
}

.nav-logo {
    height: 60px;
}

nav ul {
    display: flex;
}


nav ul li a {
    font-weight: 700;
    font-size: 16px;
    text-transform: uppercase;
    transition: color 0.3s;
}

nav ul li a:hover {
    color: #007bff;
}

/* Hero 区域 */
.hero {
    width: 100%;
    position: relative;
    overflow: hidden;
    background-color: #f8f9fa;
    padding: 40px 20px;
}

.hero-content {
    text-align: center;
}

.hero-content h1 {
    font-size: 36px;
    margin-bottom: 15px;
    color: #333;
}

.hero-content p {
    font-size: 18px;
    margin-bottom: 25px;
    color: #666;
}

/* 内容区域 */
.certifications-section {
    padding: 80px 20px;
    background-color: #fff;
}

.certifications {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    flex-direction: column;
    gap: 40px;
}

.cert-text {
    padding: 0 20px;
}

.cert-text h2 {
    font-size: 28px;
    margin-bottom: 20px;
    color: #333;
}

.cert-text p, .cert-text ul {
    font-size: 16px;
    color: #666;
    margin-bottom: 20px;
}

.cert-text ul li {
    margin-bottom: 10px;
}

/* 页脚 */
.footer {
    background-color: #333;
    color: #fff;
    padding: 50px 20px 20px;
}

.footer-container {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    flex-wrap: wrap;
    justify-content: space-between;
}

.footer-left, .footer-right {
    flex: 1;
    min-width: 300px;
    padding: 0 20px;
}

.footer-logo {
    height: 50px;
    margin-bottom: 20px;
}

.footer-title {
    font-size: 20px;
    margin-bottom: 20px;
}

.footer-text {
    font-size: 14px;
    color: #bbb;
    margin-bottom: 20px;
}

.footer-links {
    display: flex;
    flex-direction: column;
}

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

.footer-links a {
    color: #bbb;
    transition: color 0.3s;
}

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

.footer-bottom-text {
    text-align: center;
    margin-top: 40px;
    padding-top: 20px;
    border-top: 1px solid #444;
    font-size: 14px;
    color: #bbb;