/* 全局样式 */
:root {
    --primary-color: #0056b3;
    --secondary-color: #003366;
    --accent-color: #ff9800;
    --light-color: #f8f9fa;
    --dark-color: #343a40;
    --text-color: #333;
    --border-color: #ddd;
    --shadow: 0 2px 15px rgba(0, 0, 0, 0.1);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Microsoft YaHei', 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: #fff;
}

.container {
    width: 90%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 15px;
}

a {
    text-decoration: none;
    color: var(--primary-color);
    transition: all 0.3s ease;
}

a:hover {
    color: var(--secondary-color);
}

ul {
    list-style: none;
}

.btn {
    display: inline-block;
    background-color: var(--primary-color);
    color: white;
    padding: 12px 30px;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    font-size: 16px;
    font-weight: 600;
    text-transform: uppercase;
    transition: all 0.3s ease;
}

.btn:hover {
    background-color: var(--secondary-color);
    color: white;
    transform: translateY(-3px);
    box-shadow: var(--shadow);
}

.section-header {
    text-align: center;
    margin-bottom: 50px;
}

.section-header h2 {
    font-size: 36px;
    color: var(--secondary-color);
    margin-bottom: 15px;
    font-weight: 700;
}

.underline {
    height: 4px;
    width: 70px;
    background-color: var(--accent-color);
    margin: 0 auto;
}

section {
    padding: 80px 0;
}

/* 导航栏 */
header {
    background-color: white;
    box-shadow: var(--shadow);
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 1000;
    padding: 15px 0;
}

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

.logo h1 {
    font-size: 28px;
    color: var(--primary-color);
    font-weight: 700;
}

nav ul {
    display: flex;
}

nav ul li {
    margin-left: 25px;
}

nav ul li a {
    color: var(--dark-color);
    font-weight: 600;
    font-size: 16px;
    padding: 5px 0;
    position: relative;
}

nav ul li a:hover {
    color: var(--primary-color);
}

nav ul li a::after {
    content: '';
    position: absolute;
    width: 0;
    height: 2px;
    background-color: var(--primary-color);
    left: 0;
    bottom: 0;
    transition: width 0.3s ease;
}

nav ul li a:hover::after {
    width: 100%;
}

/* 首页横幅 */
.hero {
    background: url('../images/background.png') no-repeat center center/cover;
    height: 100vh;
    display: flex;
    align-items: center;
    text-align: center;
    color: white;
    margin-top: 0;
    padding-top: 0;
}

.hero-content {
    max-width: 800px;
    margin: 0 auto;
}

.hero-content h1 {
    font-size: 48px;
    margin-bottom: 15px;
    font-weight: 700;
}

.hero-content h2 {
    font-size: 36px;
    margin-bottom: 20px;
    font-weight: 600;
}

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

/* 关于我们 */
.about {
    background-color: var(--light-color);
}

.about-content {
    display: flex;
    align-items: center;
    gap: 50px;
}

.about-text {
    flex: 1;
}

.about-text p {
    margin-bottom: 20px;
    font-size: 16px;
    line-height: 1.8;
}

.about-image {
    flex: 1;
}

.about-image img {
    width: 100%;
    border-radius: 8px;
    box-shadow: var(--shadow);
}

/* 服务项目 */
.services-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 30px;
}

.service-card {
    background-color: white;
    border-radius: 8px;
    padding: 30px;
    text-align: center;
    box-shadow: var(--shadow);
    transition: all 0.3s ease;
}

.service-card:hover {
    transform: translateY(-10px);
}

.service-icon {
    font-size: 48px;
    color: var(--primary-color);
    margin-bottom: 20px;
}

.service-card h3 {
    font-size: 22px;
    margin-bottom: 15px;
    color: var(--secondary-color);
}

.service-card p {
    font-size: 16px;
    color: var(--text-color);
}

/* 我们的优势 */
.advantages {
    background-color: var(--light-color);
}

.advantages-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 30px;
}

.advantage {
    display: flex;
    align-items: center;
    background-color: white;
    border-radius: 8px;
    padding: 20px;
    box-shadow: var(--shadow);
}

.advantage-icon {
    font-size: 36px;
    color: var(--primary-color);
    margin-right: 20px;
}

.advantage-text h3 {
    font-size: 20px;
    margin-bottom: 10px;
    color: var(--secondary-color);
}

.advantage-text p {
    font-size: 15px;
}

/* 联系我们 */
.contact-content {
    display: flex;
    justify-content: space-between;
    gap: 30px;
}

.contact-info {
    display: flex;
    flex-direction: column;
    gap: 25px;
    flex: 1;
}

.contact-item {
    display: flex;
    align-items: center;
}

.contact-item i {
    font-size: 24px;
    color: var(--primary-color);
    margin-right: 15px;
}

/* 公司服务承诺卡片 */
.company-card {
    flex: 1;
    background-color: white;
    border-radius: 8px;
    box-shadow: var(--shadow);
    overflow: hidden;
}

.card-header {
    background-color: var(--primary-color);
    color: white;
    padding: 15px 20px;
    text-align: center;
}

.card-header h3 {
    margin: 0;
    font-size: 22px;
    font-weight: 600;
}

.card-body {
    padding: 20px;
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 20px;
}

.promise-item {
    display: flex;
    align-items: center;
    gap: 15px;
}

.promise-item i {
    font-size: 28px;
    color: var(--accent-color);
}

.promise-text h4 {
    margin: 0 0 5px 0;
    font-size: 18px;
    color: var(--secondary-color);
}

.promise-text p {
    margin: 0;
    font-size: 14px;
    color: var(--text-color);
}

/* 响应式设计 */
@media (max-width: 992px) {
    .about-content {
        flex-direction: column;
    }
    
    .hero-content h1 {
        font-size: 36px;
    }
    
    .hero-content h2 {
        font-size: 28px;
    }
}

@media (max-width: 768px) {
    header .container {
        flex-direction: column;
    }
    
    nav ul {
        margin-top: 15px;
    }
    
    nav ul li {
        margin-left: 15px;
        margin-right: 15px;
    }
    
    .section-header h2 {
        font-size: 28px;
    }
    
    .hero-content h1 {
        font-size: 32px;
    }
    
    .hero-content h2 {
        font-size: 24px;
    }
    
    .hero-content p {
        font-size: 16px;
    }
}

@media (max-width: 992px) {
    .contact-content {
        flex-direction: column;
    }
    
    .card-body {
        grid-template-columns: 1fr;
    }
}

/* 页脚 */
footer {
    background-color: var(--secondary-color);
    color: white;
    padding: 60px 0 20px;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 40px;
    margin-bottom: 40px;
}

.footer-logo h2 {
    font-size: 24px;
    margin-bottom: 15px;
}

.footer-links h3,
.footer-services h3 {
    font-size: 18px;
    margin-bottom: 20px;
    position: relative;
    padding-bottom: 10px;
}

.footer-links h3::after,
.footer-services h3::after {
    content: '';
    position: absolute;
    left: 0;
    bottom: 0;
    width: 50px;
    height: 2px;
    background-color: var(--accent-color);
}

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

.footer-links ul li a {
    color: #ccc;
}

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

.footer-bottom {
    text-align: center;
    padding-top: 20px;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.footer-bottom p {
    margin-bottom: 10px;
}

.footer-bottom a {
    color: #ccc;
}

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