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

:root {
    --primary-color: #1e3a8a;
    --secondary-color: #3b82f6;
    --accent-color: #60a5fa;
    --dark-color: #1e293b;
    --light-color: #f1f5f9;
    --white: #ffffff;
    --text-color: #334155;
    --border-radius: 10px;
    --transition: all 0.3s ease;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--white);
}

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

/* ==================== 导航栏 ==================== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    z-index: 1000;
    transition: var(--transition);
}

.nav-wrapper {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 0;
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 1.5rem;
    font-weight: bold;
    color: var(--primary-color);
}

.logo i {
    font-size: 2rem;
    color: var(--secondary-color);
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 2rem;
}

.nav-menu a {
    text-decoration: none;
    color: var(--text-color);
    font-weight: 500;
    padding: 0.5rem 1rem;
    border-radius: var(--border-radius);
    transition: var(--transition);
}

.nav-menu a:hover,
.nav-menu a.active {
    color: var(--secondary-color);
    background-color: rgba(59, 130, 246, 0.1);
}

/* ==================== 首页横幅 ==================== */
.hero {
    position: relative;
    height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    background-image: url('https://images.unsplash.com/photo-1451187580459-43490279c0fa?w=1920&q=80');
    background-size: cover;
    background-position: center;
    background-attachment: fixed;
}

.hero-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(135deg, rgba(30, 58, 138, 0.9) 0%, rgba(59, 130, 246, 0.85) 100%);
}

.hero-content {
    position: relative;
    z-index: 1;
    text-align: center;
    color: var(--white);
    padding: 2rem;
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    animation: fadeInUp 1s ease;
}

.hero-subtitle {
    font-size: 1.5rem;
    margin-bottom: 2rem;
    opacity: 0.95;
    animation: fadeInUp 1s ease 0.2s backwards;
}

.hero-features {
    display: flex;
    justify-content: center;
    gap: 3rem;
    margin-bottom: 2rem;
    animation: fadeInUp 1s ease 0.4s backwards;
}

.feature-item {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 1.1rem;
}

.feature-item i {
    font-size: 1.5rem;
    color: #60a5fa;
}

.cta-button {
    display: inline-block;
    padding: 1rem 2.5rem;
    background-color: var(--white);
    color: var(--primary-color);
    text-decoration: none;
    border-radius: 50px;
    font-weight: 600;
    font-size: 1.1rem;
    transition: var(--transition);
    animation: fadeInUp 1s ease 0.6s backwards;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.2);
}

.cta-button:hover {
    transform: translateY(-3px);
    box-shadow: 0 6px 20px rgba(0, 0, 0, 0.3);
}

/* ==================== 通用区块样式 ==================== */
section {
    padding: 5rem 0;
}

.section-header {
    text-align: center;
    margin-bottom: 3rem;
}

.section-header h2 {
    font-size: 2.5rem;
    color: var(--primary-color);
    margin-bottom: 1rem;
    position: relative;
    display: inline-block;
}

.section-header h2::after {
    content: '';
    position: absolute;
    bottom: -10px;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 4px;
    background: linear-gradient(90deg, var(--secondary-color), var(--accent-color));
    border-radius: 2px;
}

.section-header p {
    font-size: 1.1rem;
    color: #64748b;
    margin-top: 1.5rem;
}

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

.about-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-bottom: 3rem;
}

.about-card {
    background: var(--white);
    padding: 2rem;
    border-radius: var(--border-radius);
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    transition: var(--transition);
    text-align: center;
}

.about-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 8px 15px rgba(0, 0, 0, 0.15);
}

.card-icon {
    width: 80px;
    height: 80px;
    margin: 0 auto 1.5rem;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, var(--secondary-color), var(--accent-color));
    border-radius: 50%;
    color: var(--white);
    font-size: 2rem;
}

.about-card h3 {
    font-size: 1.5rem;
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.about-card p {
    color: var(--text-color);
    line-height: 1.8;
}

.company-info {
    background: var(--white);
    padding: 2rem;
    border-radius: var(--border-radius);
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
}

.info-item {
    padding: 1rem 0;
    border-bottom: 1px solid #e2e8f0;
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
}

.info-item:last-child {
    border-bottom: none;
}

.info-label {
    font-weight: 600;
    color: var(--primary-color);
    min-width: 180px;
}

.info-value {
    color: var(--text-color);
    flex: 1;
}

/* ==================== 项目案例 ==================== */
.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
}

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

.project-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.15);
}

.project-image {
    position: relative;
    height: 220px;
    overflow: hidden;
}

.project-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: var(--transition);
}

.project-card:hover .project-image img {
    transform: scale(1.1);
}

.project-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(30, 58, 138, 0.9);
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    transition: var(--transition);
}

.project-card:hover .project-overlay {
    opacity: 1;
}

.detail-btn {
    padding: 0.8rem 2rem;
    background: var(--white);
    color: var(--primary-color);
    border: none;
    border-radius: 50px;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
}

.detail-btn:hover {
    transform: scale(1.05);
    box-shadow: 0 4px 10px rgba(255, 255, 255, 0.3);
}

.project-info {
    padding: 1.5rem;
}

.project-info h3 {
    font-size: 1.3rem;
    color: var(--primary-color);
    margin-bottom: 0.5rem;
}

.project-category {
    color: var(--secondary-color);
    font-size: 0.9rem;
    margin-bottom: 1rem;
    font-weight: 500;
}

.project-desc {
    color: var(--text-color);
    line-height: 1.6;
    margin-bottom: 1rem;
}

.project-tags {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
}

.tag {
    padding: 0.3rem 0.8rem;
    background-color: rgba(59, 130, 246, 0.1);
    color: var(--secondary-color);
    border-radius: 20px;
    font-size: 0.85rem;
}

/* ==================== 核心优势 ==================== */
.advantages {
    background-color: var(--light-color);
}

.advantages-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.advantage-card {
    background: var(--white);
    padding: 2rem;
    border-radius: var(--border-radius);
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    transition: var(--transition);
    text-align: center;
}

.advantage-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 8px 15px rgba(0, 0, 0, 0.15);
}

.advantage-icon {
    width: 70px;
    height: 70px;
    margin: 0 auto 1.5rem;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, rgba(59, 130, 246, 0.1), rgba(96, 165, 250, 0.1));
    border-radius: 50%;
    color: var(--secondary-color);
    font-size: 2rem;
}

.advantage-card h3 {
    font-size: 1.3rem;
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.advantage-card p {
    color: var(--text-color);
    line-height: 1.8;
}

/* ==================== 联系我们 ==================== */
.contact-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 3rem;
}

.contact-info {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.contact-item {
    display: flex;
    gap: 1.5rem;
    padding: 1.5rem;
    background: var(--light-color);
    border-radius: var(--border-radius);
    transition: var(--transition);
}

.contact-item:hover {
    background: var(--white);
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.1);
}

.contact-icon {
    width: 50px;
    height: 50px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, var(--secondary-color), var(--accent-color));
    border-radius: 50%;
    color: var(--white);
    font-size: 1.3rem;
    flex-shrink: 0;
}

.contact-text h4 {
    color: var(--primary-color);
    margin-bottom: 0.5rem;
}

.contact-text p {
    color: var(--text-color);
}

.contact-map {
    height: 400px;
    border-radius: var(--border-radius);
    overflow: hidden;
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.1);
}

/* ==================== 页脚 ==================== */
.footer {
    background: var(--dark-color);
    color: var(--white);
    padding: 3rem 0 1rem;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
}

.footer-section h4 {
    margin-bottom: 1rem;
    color: var(--accent-color);
}

.footer-section p {
    margin-bottom: 0.5rem;
    opacity: 0.8;
}

.footer-section ul {
    list-style: none;
}

.footer-section ul li {
    margin-bottom: 0.5rem;
    opacity: 0.8;
}

.footer-section ul li i {
    margin-right: 0.5rem;
    color: var(--accent-color);
}

.footer-section a {
    color: var(--white);
    text-decoration: none;
    transition: var(--transition);
}

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

.footer-bottom {
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    padding-top: 1.5rem;
    text-align: center;
    opacity: 0.8;
}

.footer-bottom p {
    margin: 0.5rem 0;
}

.footer-bottom a {
    color: var(--accent-color);
    text-decoration: none;
}

/* ==================== 模态框 ==================== */
.modal {
    display: none;
    position: fixed;
    z-index: 2000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    overflow: auto;
    background-color: rgba(0, 0, 0, 0.8);
}

.modal-content {
    background-color: var(--white);
    margin: 3% auto;
    padding: 2rem;
    border-radius: var(--border-radius);
    width: 90%;
    max-width: 900px;
    position: relative;
    animation: modalFadeIn 0.3s ease;
}

.close {
    position: absolute;
    right: 1.5rem;
    top: 1rem;
    color: #aaa;
    font-size: 2rem;
    font-weight: bold;
    cursor: pointer;
    transition: var(--transition);
}

.close:hover {
    color: var(--primary-color);
}

/* ==================== 返回顶部按钮 ==================== */
.back-to-top {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    width: 50px;
    height: 50px;
    background: linear-gradient(135deg, var(--secondary-color), var(--accent-color));
    color: var(--white);
    border: none;
    border-radius: 50%;
    cursor: pointer;
    font-size: 1.5rem;
    display: none;
    align-items: center;
    justify-content: center;
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.2);
    transition: var(--transition);
    z-index: 999;
}

.back-to-top:hover {
    transform: translateY(-5px);
    box-shadow: 0 6px 15px rgba(0, 0, 0, 0.3);
}

.back-to-top.show {
    display: flex;
}

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

@keyframes modalFadeIn {
    from {
        opacity: 0;
        transform: scale(0.9);
    }
    to {
        opacity: 1;
        transform: scale(1);
    }
}

/* ==================== 响应式设计 ==================== */
@media (max-width: 768px) {
    .hero-title {
        font-size: 2rem;
    }

    .hero-subtitle {
        font-size: 1.1rem;
    }

    .hero-features {
        flex-direction: column;
        gap: 1rem;
    }

    .nav-menu {
        flex-direction: column;
        gap: 0.5rem;
    }

    .contact-content {
        grid-template-columns: 1fr;
    }

    .section-header h2 {
        font-size: 2rem;
    }

    .projects-grid,
    .advantages-grid,
    .about-grid {
        grid-template-columns: 1fr;
    }
}