/* 1. 全局与美化设置 */
:root {
    --primary-color: #0d47a1; 
    --secondary-color: #1976d2;
    --text-color: #333;
    --text-light: #666;
    --bg-light: #f8f9fa;
    --white: #fff;
    --border-color: #e0e0e0;
}
html { scroll-behavior: smooth; }
body {
    font-family: 'Noto Sans SC', sans-serif;
    margin: 0;
    padding: 0;
    color: var(--text-color);
    background-color: var(--white);
    line-height: 1.7;
}
.container { max-width: 1200px; width: 90%; margin: 0 auto; }
h1, h2, h3, h4, h5, h6 { font-family: 'Montserrat', sans-serif; }
.section-title { text-align: center; font-size: 2.2rem; font-weight: 700; margin-bottom: 10px; color: var(--primary-color); }
.section-subtitle { text-align: center; font-size: 1rem; color: #999; margin-top: 0; margin-bottom: 60px; text-transform: uppercase; letter-spacing: 2px; }

/* 2. 头部与导航 */
.top-header { background: var(--white); box-shadow: 0 2px 10px rgba(0,0,0,0.08); padding: 1rem 0; position: sticky; top: 0; z-index: 1000; width: 100%; }
.top-header .container { display: flex; justify-content: space-between; align-items: center; }
.logo-link { text-decoration: none; }
.logo { display: flex; align-items: center; }
.logo img { height: 50px; margin-right: 15px; }
.logo h1 { font-size: 1.5rem; margin: 0; color: var(--primary-color); }
.main-nav ul { margin: 0; padding: 0; list-style: none; display: flex; }
.main-nav ul li a { display: block; margin-left: 35px; font-size: 1rem; color: var(--text-color); text-decoration: none; padding-bottom: 5px; position: relative; transition: color 0.3s ease; }
.main-nav ul li a::after { content: ''; position: absolute; bottom: 0; left: 0; width: 0; height: 2px; background: var(--secondary-color); transition: width 0.3s ease; }
.main-nav ul li a:hover, .main-nav ul li a:focus, .main-nav ul li a.active { color: var(--secondary-color); }
.main-nav ul li a:hover::after, .main-nav ul li a.active::after { width: 100%; }

/* 3. Banner & 页面头部 */
.hero-banner { background: linear-gradient(rgba(0, 20, 60, 0.6), rgba(0, 20, 60, 0.6)), url('https://images.pexels.com/photos/262353/pexels-photo-262353.jpeg?auto=compress&cs=tinysrgb&w=1260&h=750&dpr=1') no-repeat center center/cover; height: 70vh; display: flex; align-items: center; justify-content: center; text-align: center; color: var(--white); padding: 0 20px; }
.hero-text h2 { font-size: 3rem; margin-bottom: 1rem; font-weight: 700; }
.hero-text p { font-size: 1.2rem; font-weight: 300; }
.btn { display: inline-block; background: var(--secondary-color); color: var(--white); padding: 12px 30px; border-radius: 50px; text-decoration: none; font-weight: 500; margin-top: 2rem; transition: background-color 0.3s ease, transform 0.3s ease; border: none; cursor: pointer; }
.btn:hover { background: var(--primary-color); transform: translateY(-3px); }
.page-header { background: #eaf0f6; text-align: center; padding: 60px 0; }
.page-header h1 { font-size: 2.5rem; color: var(--primary-color); margin: 0; }
.page-header p { font-size: 1.1rem; color: var(--text-light); margin-top: 10px; }

/* 4. 内容区域 */
.page-section { padding: 80px 0; }
.bg-light { background-color: var(--bg-light); }
.feature-container { display: grid; grid-template-columns: repeat(3, 1fr); gap: 30px; }
.feature-card { background: var(--white); padding: 30px; border-radius: 8px; text-align: center; border: 1px solid var(--border-color); box-shadow: 0 5px 15px rgba(0,0,0,0.02); }
.feature-card h3 { margin-top: 0; color: var(--primary-color); }
.about-content { display: flex; align-items: center; gap: 50px; margin-bottom: 60px; }
.about-text { flex: 1.2; text-align: justify; }
.about-text h3 { margin-top: 0; font-size: 1.8rem; color: var(--primary-color); }
.about-text p { margin-bottom: 1.5em; }
.about-image { flex: 1; }
.about-image img { width: 100%; border-radius: 8px; box-shadow: 0 10px 30px rgba(0,0,0,0.1); }
.vision-values { display: grid; grid-template-columns: 1fr 1fr; gap: 30px; text-align: center; }
.vision-card { background: var(--bg-light); padding: 30px; border-radius: 8px; border: 1px solid var(--border-color); }
.vision-card h4 { margin-top: 0; color: var(--primary-color); font-size: 1.5rem; }

/* 5. 服务项目 */
.services-container-5 { display: grid; grid-template-columns: repeat(5, 1fr); gap: 20px; }
.service-card-link { text-decoration: none; }
.service-card { background: var(--white); border-radius: 8px; overflow: hidden; box-shadow: 0 5px 15px rgba(0,0,0,0.05); text-align: center; transition: transform 0.3s ease, box-shadow 0.3s ease; height: 100%; }
.service-card:hover { transform: translateY(-10px); box-shadow: 0 15px 30px rgba(0,0,0,0.1); }
.service-card img { width: 100%; height: 160px; object-fit: cover; }
.service-card h3 { font-size: 1.2rem; margin: 20px 15px 10px; color: var(--primary-color); }
.service-item { display: flex; gap: 40px; align-items: center; margin-bottom: 60px; padding-bottom: 60px; border-bottom: 1px solid var(--border-color); }
.service-item:last-child { border-bottom: none; margin-bottom: 0; padding-bottom: 0;}
.service-item:nth-child(even) { flex-direction: row-reverse; }
.service-image { flex: 1; }
.service-image img { width: 100%; border-radius: 8px; box-shadow: 0 10px 30px rgba(0,0,0,0.1); }
.service-text { flex: 1.2; }
.service-text h3 { font-size: 1.8rem; color: var(--primary-color); margin-top: 0; }

/* 6. 联系页面 */
.contact-container { display: grid; grid-template-columns: 1fr 1.5fr; gap: 50px; }
.contact-info h3 { margin-top: 0; color: var(--primary-color); font-size: 1.8rem;}
.contact-info p { font-size: 1rem; line-height: 1.8; color: var(--text-light); }
.contact-info p strong { color: var(--text-color); }
.contact-form h3 { margin-top: 0; color: var(--primary-color); font-size: 1.8rem; }
.contact-form p { margin-bottom: 2rem; }
.contact-form form { display: flex; flex-direction: column; gap: 1rem; }
.contact-form input, .contact-form textarea { width: 100%; padding: 12px; border: 1px solid var(--border-color); border-radius: 5px; font-family: inherit; font-size: 1rem; box-sizing: border-box;}
.contact-form input:focus, .contact-form textarea:focus { outline: none; border-color: var(--secondary-color); box-shadow: 0 0 5px rgba(25, 118, 210, 0.2); }

/* 7. 页脚 */
.main-footer { background: #1c2833; color: #aeb6bf; padding: 50px 0 0; }
.footer-content { text-align: center; padding-bottom: 40px; }
.footer-content h3 { color: var(--white); font-size: 1.5rem; }
.footer-content p { font-size: 0.9rem; }
.copyright { text-align: center; padding: 20px 0; border-top: 1px solid #34495e; font-size: 0.8rem; color: #5d6d7e; }

/* 8. 响应式设计 */
@media (max-width: 992px) {
    .feature-container, .vision-values, .contact-container { grid-template-columns: 1fr; }
    .services-container-5 { grid-template-columns: repeat(3, 1fr); }
}
@media (max-width: 768px) {
    .section-title, .page-header h1 { font-size: 1.8rem; }
    .hero-text h2 { font-size: 2.2rem; }
    .hero-text p { font-size: 1rem; }
    .top-header .container, .about-content, .service-item, .service-item:nth-child(even) { flex-direction: column; text-align: center; }
    .service-item .service-text { text-align: justify; }
    .logo { margin-bottom: 15px; }
    .main-nav ul { justify-content: center; width: 100%; flex-wrap: wrap; }
    .main-nav ul li a { margin: 5px 10px; }
    .services-container-5 { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 576px) {
    .services-container-5 { grid-template-columns: 1fr; }
    .logo h1 { font-size: 1.2rem; }
}