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

/* 屏幕阅读器专用 */
.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border-width: 0;
}

body {
    font-family: 'Microsoft YaHei', 'PingFang SC', Arial, sans-serif;
    line-height: 1.6;
    color: #333;
    overflow-x: hidden;
}

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

/* 头部导航 */
.header {
    background: #fff;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    position: fixed;
    width: 100%;
    top: 0;
    z-index: 1000;
}

.header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 15px 20px;
}

.logo h1 {
    color: #2c5aa0;
    font-size: 28px;
    font-weight: bold;
}

.subtitle {
    color: #666;
    font-size: 12px;
    margin-top: 2px;
}

.nav ul {
    list-style: none;
    display: flex;
    gap: 30px;
}

.nav a {
    text-decoration: none;
    color: #333;
    font-weight: 500;
    transition: color 0.3s;
    position: relative;
}

.nav a:hover {
    color: #2c5aa0;
}

.nav a::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background: #2c5aa0;
    transition: width 0.3s;
}

.nav a:hover::after {
    width: 100%;
}

/* 主横幅 */
.hero {
    margin-top: 80px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 120px 20px;
    text-align: center;
}

.hero h2 {
    font-size: 48px;
    margin-bottom: 20px;
    font-weight: bold;
}

.hero p {
    font-size: 20px;
    margin-bottom: 30px;
    opacity: 0.95;
}

/* 按钮 */
.btn {
    display: inline-block;
    padding: 14px 40px;
    text-decoration: none;
    border-radius: 50px;
    font-weight: bold;
    transition: all 0.3s;
    border: none;
    cursor: pointer;
    font-size: 16px;
}

.btn-primary {
    background: #fff;
    color: #667eea;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 20px rgba(0,0,0,0.2);
}

/* 章节标题 */
.section-title {
    text-align: center;
    font-size: 36px;
    margin-bottom: 60px;
    color: #333;
    position: relative;
    padding-bottom: 20px;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 80px;
    height: 4px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    border-radius: 2px;
}

/* 关于我们 */
.about {
    padding: 80px 20px;
    background: #f9fafb;
}

.about-content {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 60px;
    align-items: center;
}

.about-text p {
    margin-bottom: 20px;
    line-height: 1.8;
    color: #666;
}

.about-stats {
    display: flex;
    flex-direction: column;
    gap: 30px;
}

.stat-item {
    text-align: center;
    padding: 30px;
    background: white;
    border-radius: 10px;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
}

.stat-number {
    font-size: 48px;
    font-weight: bold;
    color: #667eea;
    margin-bottom: 10px;
}

.stat-label {
    color: #666;
    font-size: 16px;
}

/* 业务范围 */
.services {
    padding: 80px 20px;
    background: white;
}

.services-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
}

.service-card {
    padding: 40px 30px;
    background: #f9fafb;
    border-radius: 10px;
    text-align: center;
    transition: all 0.3s;
}

.service-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 30px rgba(0,0,0,0.1);
}

.service-icon {
    font-size: 60px;
    margin-bottom: 20px;
}

.service-card h3 {
    font-size: 22px;
    margin-bottom: 15px;
    color: #333;
}

.service-card p {
    color: #666;
    line-height: 1.6;
}

/* 项目案例 */
.projects {
    padding: 80px 20px;
    background: #f9fafb;
}

.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 30px;
}

.project-card {
    background: white;
    border-radius: 10px;
    overflow: hidden;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
    transition: all 0.3s;
}

.project-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 30px rgba(0,0,0,0.15);
}

.project-image {
    height: 250px;
    overflow: hidden;
}

.placeholder-img {
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 24px;
    font-weight: bold;
}

.project-info {
    padding: 25px;
}

.project-info h3 {
    font-size: 20px;
    margin-bottom: 10px;
    color: #333;
}

.project-info p {
    color: #666;
    line-height: 1.6;
}

/* 联系我们 */
.contact {
    padding: 80px 20px;
    background: white;
}

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

.contact-info {
    display: flex;
    flex-direction: column;
    gap: 30px;
}

.info-item h3 {
    font-size: 20px;
    margin-bottom: 10px;
    color: #333;
}

.info-item p {
    color: #666;
    line-height: 1.6;
}

.contact-form form {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.contact-form input,
.contact-form textarea {
    padding: 15px;
    border: 1px solid #ddd;
    border-radius: 5px;
    font-size: 15px;
    font-family: inherit;
}

.contact-form input:focus,
.contact-form textarea:focus {
    outline: none;
    border-color: #667eea;
}

.contact-form button {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
}

.contact-form button:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 20px rgba(102, 126, 234, 0.3);
}

/* 底部 */
.footer {
    background: #1f2937;
    color: white;
    padding: 40px 20px;
}

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

.footer-info p {
    margin: 10px 0;
    color: #9ca3af;
}

.footer-info a {
    color: #9ca3af;
    text-decoration: none;
    transition: color 0.3s;
}

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

/* 响应式设计 */
@media (max-width: 768px) {
    .nav ul {
        gap: 15px;
    }
    
    .hero h2 {
        font-size: 32px;
    }
    
    .hero p {
        font-size: 16px;
    }
    
    .about-content {
        grid-template-columns: 1fr;
    }
    
    .contact-content {
        grid-template-columns: 1fr;
    }
    
    .projects-grid {
        grid-template-columns: 1fr;
    }
}