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

:root {
    --primary-color: #2563eb;
    --secondary-color: #1e40af;
    --accent-color: #3b82f6;
    --text-dark: #1f2937;
    --text-light: #6b7280;
    --bg-light: #f9fafb;
    --white: #ffffff;
    --shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 25px rgba(0, 0, 0, 0.1);
    --transition: all 0.3s ease;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", Arial, sans-serif;
    line-height: 1.6;
    color: var(--text-dark);
    overflow-x: hidden;
}

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

/* 导航栏样式 */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    background: var(--white);
    box-shadow: var(--shadow);
    z-index: 1000;
    transition: var(--transition);
}

.navbar.scrolled {
    box-shadow: var(--shadow-lg);
}

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

.logo {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-size: 1.5rem;
    font-weight: bold;
    color: var(--primary-color);
}

.logo img {
    height: 40px;
    width: auto;
}

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

.nav-link {
    text-decoration: none;
    color: var(--text-dark);
    font-weight: 500;
    transition: var(--transition);
    position: relative;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--primary-color);
    transition: var(--transition);
}

.nav-link:hover,
.nav-link.active {
    color: var(--primary-color);
}

.nav-link:hover::after,
.nav-link.active::after {
    width: 100%;
}

.hamburger {
    display: none;
    flex-direction: column;
    gap: 4px;
    cursor: pointer;
}

.hamburger span {
    width: 25px;
    height: 3px;
    background: var(--text-dark);
    transition: var(--transition);
}

/* 首页横幅 */
.hero {
    position: relative;
    height: 100vh;
    min-height: 600px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
}

.hero-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.3);
}

.hero-content {
    position: relative;
    z-index: 1;
    text-align: center;
    color: var(--white);
    animation: fadeInUp 1s ease;
}

.hero-title {
    font-size: 3.5rem;
    font-weight: bold;
    margin-bottom: 1.5rem;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.2);
}

.hero-subtitle {
    font-size: 1.5rem;
    margin-bottom: 2.5rem;
    opacity: 0.95;
}

.hero-buttons {
    display: flex;
    gap: 1.5rem;
    justify-content: center;
    flex-wrap: wrap;
}

.btn {
    display: inline-block;
    padding: 0.875rem 2rem;
    text-decoration: none;
    border-radius: 50px;
    font-weight: 600;
    transition: var(--transition);
    cursor: pointer;
    border: none;
    font-size: 1rem;
}

.btn-primary {
    background: var(--white);
    color: var(--primary-color);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 15px rgba(255, 255, 255, 0.3);
}

.btn-secondary {
    background: transparent;
    color: var(--white);
    border: 2px solid var(--white);
}

.btn-secondary:hover {
    background: var(--white);
    color: var(--primary-color);
}

.btn-block {
    width: 100%;
}

.scroll-indicator {
    position: absolute;
    bottom: 30px;
    left: 50%;
    transform: translateX(-50%);
    animation: bounce 2s infinite;
}

.scroll-indicator span {
    display: block;
    width: 20px;
    height: 30px;
    border: 2px solid var(--white);
    border-radius: 15px;
    position: relative;
}

.scroll-indicator span::before {
    content: '';
    position: absolute;
    top: 5px;
    left: 50%;
    transform: translateX(-50%);
    width: 4px;
    height: 8px;
    background: var(--white);
    border-radius: 2px;
    animation: scroll 1.5s infinite;
}

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

.section-header {
    text-align: center;
    margin-bottom: 4rem;
}

.section-title {
    font-size: 2.5rem;
    font-weight: bold;
    margin-bottom: 1rem;
    color: var(--text-dark);
}

.title-underline {
    width: 80px;
    height: 4px;
    background: linear-gradient(90deg, var(--primary-color), var(--accent-color));
    margin: 0 auto 1rem;
    border-radius: 2px;
}

.section-subtitle {
    font-size: 1.125rem;
    color: var(--text-light);
}

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

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

.about-text h3 {
    font-size: 2rem;
    margin-bottom: 1.5rem;
    color: var(--primary-color);
}

.about-text p {
    font-size: 1.125rem;
    line-height: 1.8;
    margin-bottom: 1.5rem;
    color: var(--text-dark);
}

.about-features {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.feature-item {
    text-align: center;
    padding: 1.5rem;
    background: var(--white);
    border-radius: 10px;
    box-shadow: var(--shadow);
    transition: var(--transition);
}

.feature-item:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

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

.feature-item h4 {
    font-size: 1.25rem;
    margin-bottom: 0.5rem;
    color: var(--text-dark);
}

.feature-item p {
    color: var(--text-light);
}

/* 服务项目 */
.services-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
}

.service-card {
    background: var(--white);
    padding: 2.5rem;
    border-radius: 15px;
    box-shadow: var(--shadow);
    transition: var(--transition);
    border-top: 4px solid var(--primary-color);
}

.service-card:hover {
    transform: translateY(-10px);
    box-shadow: var(--shadow-lg);
}

.service-icon {
    font-size: 3.5rem;
    margin-bottom: 1.5rem;
}

.service-card h3 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    color: var(--text-dark);
}

.service-card > p {
    color: var(--text-light);
    margin-bottom: 1.5rem;
    line-height: 1.8;
}

.service-list {
    list-style: none;
}

.service-list li {
    padding: 0.5rem 0;
    color: var(--text-dark);
    position: relative;
    padding-left: 1.5rem;
}

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

/* 成功案例 */
.cases {
    background: var(--bg-light);
}

.cases-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 2.5rem;
}

.case-card {
    background: var(--white);
    border-radius: 15px;
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: var(--transition);
}

.case-card:hover {
    transform: translateY(-10px);
    box-shadow: var(--shadow-lg);
}

.case-image {
    width: 100%;
    height: 250px;
    overflow: hidden;
}

.case-placeholder {
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    display: flex;
    align-items: center;
    justify-content: center;
}

.case-placeholder span {
    font-size: 5rem;
}

.case-info {
    padding: 2rem;
}

.case-info h3 {
    font-size: 1.5rem;
    margin-bottom: 0.5rem;
    color: var(--text-dark);
}

.case-category {
    display: inline-block;
    padding: 0.25rem 0.75rem;
    background: var(--primary-color);
    color: var(--white);
    border-radius: 20px;
    font-size: 0.875rem;
    margin-bottom: 1rem;
}

.case-desc {
    color: var(--text-light);
    line-height: 1.8;
}

/* 联系我们 */
.contact-content {
    max-width: 800px;
    margin: 0 auto;
}

.contact-info {
    display: flex;
    flex-direction: column;
    gap: 2rem;
}

.contact-item {
    display: flex;
    gap: 1.5rem;
    padding: 1.5rem;
    background: var(--bg-light);
    border-radius: 10px;
    transition: var(--transition);
}

.contact-item:hover {
    box-shadow: var(--shadow);
}

.contact-icon {
    font-size: 2.5rem;
    flex-shrink: 0;
}

.contact-details h4 {
    font-size: 1.125rem;
    margin-bottom: 0.5rem;
    color: var(--text-dark);
}

.contact-details p,
.contact-details a {
    color: var(--text-light);
    text-decoration: none;
}

.contact-details a:hover {
    color: var(--primary-color);
}

/* 页脚 */
.footer {
    background: var(--text-dark);
    color: var(--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-logo img {
    height: 40px;
    width: auto;
    margin-bottom: 1rem;
    filter: brightness(0) invert(1);
}

.footer-logo p {
    color: rgba(255, 255, 255, 0.8);
}

.footer h4 {
    margin-bottom: 1rem;
    font-size: 1.125rem;
}

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

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

.footer-links a,
.footer-contact p {
    color: rgba(255, 255, 255, 0.7);
    text-decoration: none;
    transition: var(--transition);
}

.footer-links a:hover {
    color: var(--white);
}

.footer-bottom {
    padding-top: 1.5rem;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    text-align: center;
    color: rgba(255, 255, 255, 0.7);
}

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

.footer-bottom a {
    color: rgba(255, 255, 255, 0.7);
    text-decoration: none;
    transition: var(--transition);
}

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

/* 返回顶部按钮 */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    background: var(--primary-color);
    color: var(--white);
    border: none;
    border-radius: 50%;
    font-size: 1.5rem;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transition: var(--transition);
    z-index: 999;
    box-shadow: var(--shadow);
}

.back-to-top.visible {
    opacity: 1;
    visibility: visible;
}

.back-to-top:hover {
    background: var(--secondary-color);
    transform: translateY(-5px);
}

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

@keyframes bounce {
    0%, 20%, 50%, 80%, 100% {
        transform: translateX(-50%) translateY(0);
    }
    40% {
        transform: translateX(-50%) translateY(-10px);
    }
    60% {
        transform: translateX(-50%) translateY(-5px);
    }
}

@keyframes scroll {
    0% {
        opacity: 1;
        transform: translateX(-50%) translateY(0);
    }
    100% {
        opacity: 0;
        transform: translateX(-50%) translateY(10px);
    }
}

/* 响应式设计 */
@media (max-width: 768px) {
    .nav-menu {
        position: fixed;
        top: 70px;
        left: -100%;
        width: 100%;
        height: calc(100vh - 70px);
        background: var(--white);
        flex-direction: column;
        padding: 2rem;
        gap: 1rem;
        transition: var(--transition);
        box-shadow: var(--shadow);
    }

    .nav-menu.active {
        left: 0;
    }

    .hamburger {
        display: flex;
    }

    .hamburger.active span:nth-child(1) {
        transform: rotate(45deg) translate(5px, 5px);
    }

    .hamburger.active span:nth-child(2) {
        opacity: 0;
    }

    .hamburger.active span:nth-child(3) {
        transform: rotate(-45deg) translate(7px, -6px);
    }

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

    .hero-subtitle {
        font-size: 1.125rem;
    }

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

    .about-features {
        grid-template-columns: 1fr;
    }

    .services-grid,
    .cases-grid {
        grid-template-columns: 1fr;
    }

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

    .back-to-top {
        bottom: 20px;
        right: 20px;
        width: 45px;
        height: 45px;
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: 1.75rem;
    }

    .hero-buttons {
        flex-direction: column;
        width: 100%;
    }

    .btn {
        width: 100%;
    }
}