/* 全局样式 */
:root {
    --primary-color: #0056b3;
    --secondary-color: #00a0e9;
    --accent-color: #ff6b00;
    --text-color: #333;
    --light-text: #fff;
    --dark-bg: #1a1a1a;
    --light-bg: #f8f9fa;
    --gray-bg: #f0f2f5;
    --border-color: #e0e0e0;
    --shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    --transition: all 0.3s ease;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: #fff;
}

.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

a {
    text-decoration: none;
    color: var(--primary-color);
    transition: var(--transition);
}

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

ul {
    list-style: none;
}

.btn {
    display: inline-block;
    background-color: var(--primary-color);
    color: var(--light-text);
    padding: 12px 30px;
    border-radius: 4px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 1px;
    transition: var(--transition);
    border: none;
    cursor: pointer;
}

.btn:hover {
    background-color: var(--accent-color);
    color: var(--light-text);
    transform: translateY(-2px);
    box-shadow: var(--shadow);
}

.section-title {
    font-size: 2.5rem;
    text-align: center;
    margin-bottom: 50px;
    color: var(--primary-color);
    position: relative;
    padding-bottom: 15px;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 80px;
    height: 4px;
    background-color: var(--accent-color);
}

section {
    padding: 80px 0;
}

/* 头部导航 */
header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    background-color: rgba(255, 255, 255, 0.95);
    box-shadow: var(--shadow);
    z-index: 1000;
    padding: 15px 0;
    transition: var(--transition);
}

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

.logo h1 {
    font-size: 1.8rem;
    color: var(--primary-color);
    font-weight: 700;
}

nav ul {
    display: flex;
}

nav ul li {
    margin-left: 30px;
}

nav ul li a {
    color: var(--text-color);
    font-weight: 500;
    position: relative;
    padding: 5px 0;
}

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

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

/* 英雄区域 */
.hero {
    height: 100vh;
    background: linear-gradient(rgba(0, 0, 0, 0.6), rgba(0, 0, 0, 0.6)), url('https://source.unsplash.com/random/1920x1080/?technology,digital') no-repeat center center/cover;
    display: flex;
    align-items: center;
    text-align: center;
    color: var(--light-text);
    margin-top: 0;
    padding-top: 80px;
}

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

.hero-content h2 {
    font-size: 3.5rem;
    margin-bottom: 20px;
    animation: fadeInDown 1s ease;
}

.hero-content p {
    font-size: 1.2rem;
    margin-bottom: 15px;
    animation: fadeInUp 1s ease;
}

.hero-content .btn {
    margin-top: 30px;
    animation: fadeIn 1.5s ease;
}

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

.about-content {
    display: flex;
    flex-wrap: wrap;
    gap: 40px;
}

.about-text {
    flex: 1;
    min-width: 300px;
}

.about-text p {
    margin-bottom: 20px;
    font-size: 1.1rem;
}

.about-stats {
    flex: 1;
    min-width: 300px;
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 30px;
}

.stat-item {
    background-color: #fff;
    padding: 30px;
    border-radius: 8px;
    text-align: center;
    box-shadow: var(--shadow);
    transition: var(--transition);
}

.stat-item:hover {
    transform: translateY(-10px);
}

.stat-item h3 {
    font-size: 2.5rem;
    color: var(--accent-color);
    margin-bottom: 10px;
}

/* 业务服务 */
.services-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 30px;
}

.service-card {
    background-color: #fff;
    border-radius: 8px;
    padding: 30px;
    text-align: center;
    box-shadow: var(--shadow);
    transition: var(--transition);
}

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

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

.service-icon svg {
    fill: none;
    stroke: var(--primary-color);
    stroke-width: 1.5;
    stroke-linecap: round;
    stroke-linejoin: round;
}

.service-card h3 {
    font-size: 1.5rem;
    margin-bottom: 15px;
    color: var(--primary-color);
}

/* 企业成就 */
.achievements {
    background-color: var(--gray-bg);
}

.achievements-timeline {
    position: relative;
    max-width: 800px;
    margin: 0 auto;
}

.achievements-timeline::before {
    content: '';
    position: absolute;
    top: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 4px;
    height: 100%;
    background-color: var(--primary-color);
}

.timeline-item {
    position: relative;
    margin-bottom: 50px;
}

.timeline-item:last-child {
    margin-bottom: 0;
}

.timeline-date {
    position: absolute;
    top: 0;
    left: 50%;
    transform: translateX(-50%);
    background-color: var(--primary-color);
    color: var(--light-text);
    padding: 8px 16px;
    border-radius: 20px;
    font-weight: 600;
    z-index: 1;
}

.timeline-content {
    position: relative;
    width: 45%;
    padding: 20px;
    background-color: #fff;
    border-radius: 8px;
    box-shadow: var(--shadow);
}

.timeline-item:nth-child(odd) .timeline-content {
    left: 55%;
}

.timeline-item:nth-child(even) .timeline-content {
    left: 0;
}

.timeline-content h3 {
    font-size: 1.3rem;
    margin-bottom: 10px;
    color: var(--primary-color);
}

/* 联系我们 */
.contact-content {
    display: flex;
    flex-wrap: wrap;
    gap: 40px;
}

.contact-info {
    flex: 1;
    min-width: 300px;
}

.info-item {
    margin-bottom: 30px;
}

.info-item h3 {
    font-size: 1.3rem;
    margin-bottom: 10px;
    color: var(--primary-color);
}

.contact-form {
    flex: 1;
    min-width: 300px;
}

.form-group {
    margin-bottom: 20px;
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 12px 15px;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    font-size: 1rem;
    transition: var(--transition);
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 2px rgba(0, 86, 179, 0.2);
}

.form-group textarea {
    height: 150px;
    resize: vertical;
}

/* 页脚 */
footer {
    background-color: var(--dark-bg);
    color: var(--light-text);
    padding: 60px 0 20px;
}

.footer-content {
    display: flex;
    flex-wrap: wrap;
    gap: 40px;
    margin-bottom: 40px;
}

.footer-logo,
.footer-links,
.footer-social {
    flex: 1;
    min-width: 250px;
}

.footer-logo h2 {
    font-size: 1.8rem;
    margin-bottom: 15px;
}

.footer-links h3,
.footer-social h3 {
    font-size: 1.3rem;
    margin-bottom: 20px;
    position: relative;
    padding-bottom: 10px;
}

.footer-links h3::after,
.footer-social h3::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 50px;
    height: 3px;
    background-color: var(--accent-color);
}

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

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

.footer-links ul li a:hover {
    color: var(--light-text);
}

.social-icons {
    display: flex;
    gap: 15px;
}

.social-icon {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    background-color: rgba(255, 255, 255, 0.1);
    border-radius: 50%;
    transition: var(--transition);
}

.social-icon:hover {
    background-color: var(--accent-color);
    transform: translateY(-5px);
}

.social-icon svg {
    fill: none;
    stroke: var(--light-text);
    stroke-width: 1.5;
    stroke-linecap: round;
    stroke-linejoin: round;
}

.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: var(--light-text);
}

/* 动画 */
@keyframes fadeIn {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

@keyframes fadeInDown {
    from {
        opacity: 0;
        transform: translateY(-30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* 响应式设计 */
@media screen and (max-width: 992px) {
    .section-title {
        font-size: 2rem;
    }
    
    .hero-content h2 {
        font-size: 2.8rem;
    }
    
    .timeline-content {
        width: 100%;
        left: 0 !important;
        margin-top: 60px;
    }
    
    .achievements-timeline::before {
        left: 20px;
    }
    
    .timeline-date {
        left: 20px;
        transform: translateX(0);
    }
}

@media screen and (max-width: 768px) {
    header .container {
        flex-direction: column;
    }
    
    nav {
        margin-top: 15px;
    }
    
    nav ul {
        justify-content: center;
    }
    
    nav ul li {
        margin: 0 10px;
    }
    
    .hero-content h2 {
        font-size: 2.2rem;
    }
    
    .about-stats {
        grid-template-columns: 1fr;
    }
}

@media screen and (max-width: 576px) {
    section {
        padding: 60px 0;
    }
    
    .hero-content h2 {
        font-size: 1.8rem;
    }
    
    .hero-content p {
        font-size: 1rem;
    }
    
    .btn {
        padding: 10px 20px;
    }
    
    .section-title {
        font-size: 1.8rem;
        margin-bottom: 30px;
    }
    
    .footer-content {
        flex-direction: column;
        gap: 30px;
    }
}