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

:root {
    --primary-color: #4b5563;
    --secondary-color: #1f2937;
    --accent-color: #6b7280;
    --text-dark: #1a1a1a;
    --text-light: #6b7280;
    --bg-light: #f9fafb;
    --bg-white: #ffffff;
    --border-color: #e5e7eb;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 
                 'Microsoft YaHei', 'Helvetica Neue', Helvetica, Arial, sans-serif;
    line-height: 1.6;
    color: var(--text-dark);
    background-color: var(--bg-white);
}

html {
    scroll-behavior: smooth;
}

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

/* 导航栏 */
.navbar {
    background-color: var(--bg-white);
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    position: sticky;
    top: 0;
    z-index: 1000;
    padding: 1rem 0;
}

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

.logo h1 {
    font-size: 1.5rem;
    color: var(--primary-color);
    margin-bottom: 0.25rem;
}

.logo .subtitle {
    font-size: 0.875rem;
    color: var(--text-light);
}

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

.nav-links a {
    text-decoration: none;
    color: var(--text-dark);
    font-weight: 500;
    transition: color 0.3s ease;
}

.nav-links a:hover {
    color: var(--primary-color);
}

/* 主横幅 */
.hero {
    background: linear-gradient(135deg, rgba(75, 85, 99, 0.88) 0%, rgba(26, 26, 26, 0.92) 100%),
                url('https://images.unsplash.com/photo-1578575437130-527eed3abbec?w=1920&q=80') center/cover no-repeat;
    color: white;
    padding: 8rem 0;
    text-align: center;
    position: relative;
}

.hero-content {
    max-width: 800px;
    margin: 0 auto;
    padding: 0 20px;
}

.hero-title {
    font-size: 3rem;
    font-weight: 700;
    margin-bottom: 1rem;
    animation: fadeInUp 1s ease;
}

.hero-subtitle {
    font-size: 1.25rem;
    margin-bottom: 2rem;
    opacity: 0.9;
    animation: fadeInUp 1s ease 0.2s both;
}

.cta-button {
    display: inline-block;
    padding: 1rem 2.5rem;
    background-color: white;
    color: var(--primary-color);
    text-decoration: none;
    border-radius: 50px;
    font-weight: 600;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    animation: fadeInUp 1s ease 0.4s both;
}

.cta-button:hover {
    transform: translateY(-3px);
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.2);
}

/* 关于我们 */
.about {
    padding: 6rem 0;
    background-color: var(--bg-light);
}

.section-title {
    text-align: center;
    font-size: 2.5rem;
    margin-bottom: 3rem;
    color: var(--text-dark);
    position: relative;
}

.section-title::after {
    content: '';
    display: block;
    width: 60px;
    height: 4px;
    background-color: var(--primary-color);
    margin: 1rem auto 0;
    border-radius: 2px;
}

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

.about-card {
    background-color: var(--bg-white);
    padding: 2.5rem;
    border-radius: 12px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
    text-align: center;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.about-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 12px 24px rgba(0, 0, 0, 0.1);
}

.about-card .icon {
    font-size: 3rem;
    margin-bottom: 1rem;
}

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

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

/* 经营范围 */
.business {
    padding: 6rem 0;
    background-color: var(--bg-white);
}

.business-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
}

.business-item {
    background-color: var(--bg-light);
    padding: 2rem;
    border-radius: 12px;
    border-left: 4px solid var(--primary-color);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.business-item:hover {
    transform: translateX(5px);
    box-shadow: 0 8px 16px rgba(0, 0, 0, 0.08);
}

.business-icon {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.business-item h3 {
    font-size: 1.25rem;
    margin-bottom: 1rem;
    color: var(--primary-color);
}

.business-item ul {
    list-style: none;
}

.business-item ul li {
    padding: 0.5rem 0;
    color: var(--text-light);
    position: relative;
    padding-left: 1.5rem;
}

.business-item ul li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: var(--primary-color);
    font-weight: bold;
}

/* 联系我们 */
.contact {
    padding: 6rem 0;
    background-color: var(--bg-light);
}

.contact-content {
    max-width: 900px;
    margin: 0 auto;
}

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

.contact-item {
    background-color: var(--bg-white);
    padding: 2rem;
    border-radius: 12px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
}

.contact-item h3 {
    font-size: 1.25rem;
    margin-bottom: 1rem;
    color: var(--primary-color);
}

.contact-item p {
    color: var(--text-light);
    line-height: 1.8;
}

/* 页脚 */
.footer {
    background-color: #1a1a1a;
    color: white;
    padding: 3rem 0 1.5rem;
}

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

.footer-section h3 {
    font-size: 1.25rem;
    margin-bottom: 1rem;
}

.footer-section h4 {
    font-size: 1.1rem;
    margin-bottom: 1rem;
}

.footer-section p {
    opacity: 0.8;
    line-height: 1.8;
    font-size: 0.9rem;
}

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

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

.footer-section ul li a {
    color: white;
    text-decoration: none;
    opacity: 0.8;
    transition: opacity 0.3s ease;
}

.footer-section ul li a:hover {
    opacity: 1;
}

.footer-bottom {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.footer-bottom p {
    opacity: 0.7;
    font-size: 0.9rem;
}

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

/* 响应式设计 */
@media (max-width: 768px) {
    .navbar .container {
        flex-direction: column;
        gap: 1rem;
    }

    .nav-links {
        gap: 1rem;
        flex-wrap: wrap;
        justify-content: center;
    }

    .hero {
        padding: 4rem 0;
    }

    .hero-title {
        font-size: 2rem;
    }

    .hero-subtitle {
        font-size: 1rem;
    }

    .section-title {
        font-size: 2rem;
    }

    .about-content,
    .business-grid,
    .contact-info {
        grid-template-columns: 1fr;
    }

    .footer-content {
        grid-template-columns: 1fr;
        text-align: center;
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: 1.5rem;
    }

    .section-title {
        font-size: 1.75rem;
    }

    .cta-button {
        padding: 0.875rem 2rem;
    }
}