/* ===== CSS 变量 ===== */
:root {
    --color-primary: #1a237e;
    --color-primary-light: #3949ab;
    --color-primary-dark: #0d1442;
    --color-accent: #00bcd4;
    --color-accent-light: #4dd0e1;
    --color-white: #ffffff;
    --color-bg: #f5f7fa;
    --color-text: #333333;
    --color-text-light: #666666;
    --max-width: 1200px;
    --navbar-height: 70px;
    --font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
    --shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    --shadow-hover: 0 8px 25px rgba(0, 0, 0, 0.15);
    --transition: all 0.3s ease;
}

/* ===== 基础重置 ===== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-family);
    color: var(--color-text);
    background-color: var(--color-white);
    line-height: 1.6;
}

a {
    text-decoration: none;
    color: inherit;
}

ul {
    list-style: none;
}

img {
    max-width: 100%;
    height: auto;
}

/* ===== 容器 ===== */
.container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 20px;
}

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

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

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 100%;
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--color-primary);
}

.nav-links {
    display: flex;
    gap: 30px;
}

.nav-links a {
    color: var(--color-text);
    font-size: 0.95rem;
    font-weight: 500;
    padding: 8px 0;
    position: relative;
    transition: var(--transition);
}

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

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

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

.menu-toggle {
    display: none;
    background: none;
    border: none;
    cursor: pointer;
    padding: 5px;
    color: var(--color-primary);
}

/* ===== Hero 首屏 ===== */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    background: linear-gradient(135deg, var(--color-primary-dark) 0%, var(--color-primary) 50%, var(--color-primary-light) 100%);
    color: var(--color-white);
    padding-top: var(--navbar-height);
}

.hero-content {
    padding: 20px;
}

.hero-title {
    font-size: 3rem;
    font-weight: 700;
    margin-bottom: 20px;
    text-shadow: 0 2px 10px rgba(0, 0, 0, 0.3);
}

.hero-subtitle {
    font-size: 1.25rem;
    opacity: 0.9;
    margin-bottom: 40px;
}

.hero-buttons {
    display: flex;
    gap: 20px;
    justify-content: center;
    flex-wrap: wrap;
}

/* ===== 按钮 ===== */
.btn {
    display: inline-block;
    padding: 14px 32px;
    border-radius: 50px;
    font-size: 1rem;
    font-weight: 600;
    transition: var(--transition);
    cursor: pointer;
}

.btn-primary {
    background: var(--color-accent);
    color: var(--color-white);
    border: none;
}

.btn-primary:hover {
    background: var(--color-accent-light);
    transform: translateY(-2px);
    box-shadow: 0 4px 15px rgba(0, 188, 212, 0.4);
}

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

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

/* ===== 板块通用样式 ===== */
.section {
    padding: 100px 0;
}

.section-alt {
    background: var(--color-bg);
}

.section-title {
    font-size: 2.25rem;
    font-weight: 700;
    color: var(--color-primary);
    text-align: center;
    margin-bottom: 20px;
}

.section-subtitle {
    text-align: center;
    color: var(--color-text-light);
    font-size: 1.1rem;
    margin-bottom: 50px;
    max-width: 700px;
    margin-left: auto;
    margin-right: auto;
}

/* ===== 公司简介 ===== */
.about-content {
    max-width: 800px;
    margin: 0 auto;
    text-align: center;
}

.about-content p {
    margin-bottom: 20px;
    font-size: 1.05rem;
    color: var(--color-text-light);
}

/* ===== 核心服务 ===== */
.services-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
    margin-top: 50px;
}

.service-card {
    background: var(--color-white);
    border-radius: 16px;
    padding: 40px 30px;
    box-shadow: var(--shadow);
    transition: var(--transition);
}

.service-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-hover);
}

.service-icon {
    width: 80px;
    height: 80px;
    background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-light) 100%);
    border-radius: 20px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 25px;
    color: var(--color-white);
}

.service-title {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--color-primary);
    margin-bottom: 15px;
}

.service-list {
    color: var(--color-text-light);
    font-size: 0.95rem;
}

.service-list li {
    margin-bottom: 8px;
    padding-left: 20px;
    position: relative;
}

.service-list li::before {
    content: '';
    position: absolute;
    left: 0;
    top: 10px;
    width: 6px;
    height: 6px;
    background: var(--color-accent);
    border-radius: 50%;
}

/* ===== AI 智能化服务 ===== */
.ai-card {
    background: var(--color-white);
    border-radius: 16px;
    padding: 35px 30px;
    box-shadow: var(--shadow);
    transition: var(--transition);
}

.ai-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-hover);
}

.ai-card-large {
    margin-bottom: 40px;
    padding: 50px 40px;
}

.ai-icon {
    width: 70px;
    height: 70px;
    background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-light) 100%);
    border-radius: 16px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 20px;
    color: var(--color-white);
}

.ai-title {
    font-size: 1.3rem;
    font-weight: 600;
    color: var(--color-primary);
    margin-bottom: 15px;
}

.ai-content {
    color: var(--color-text-light);
}

.ai-intro {
    margin-bottom: 15px;
    line-height: 1.8;
}

.ai-highlight {
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--color-primary);
    margin: 20px 0 10px;
}

.ai-list {
    margin-left: 20px;
}

.ai-list li {
    margin-bottom: 10px;
    padding-left: 15px;
    position: relative;
}

.ai-list li::before {
    content: '';
    position: absolute;
    left: 0;
    top: 10px;
    width: 6px;
    height: 6px;
    background: var(--color-accent);
    border-radius: 50%;
}

.ai-note {
    font-weight: 500;
    color: var(--color-primary-light);
    margin: 20px 0;
}

.ai-desc {
    color: var(--color-text-light);
    margin-bottom: 15px;
}

.ai-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 25px;
}

/* ===== 服务流程 ===== */
.process-timeline {
    display: flex;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 20px;
    margin-top: 50px;
    position: relative;
}

.process-timeline::before {
    content: '';
    position: absolute;
    top: 35px;
    left: 50%;
    transform: translateX(-50%);
    width: 90%;
    height: 3px;
    background: linear-gradient(90deg, var(--color-primary), var(--color-accent));
    z-index: 0;
}

.step {
    flex: 1;
    min-width: 140px;
    text-align: center;
    position: relative;
    z-index: 1;
}

.step-number {
    width: 70px;
    height: 70px;
    background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-light) 100%);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 20px;
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--color-white);
    box-shadow: var(--shadow);
}

.step-title {
    font-size: 1rem;
    font-weight: 600;
    color: var(--color-primary);
    margin-bottom: 8px;
}

.step-desc {
    font-size: 0.85rem;
    color: var(--color-text-light);
    line-height: 1.5;
}

/* ===== 成功案例 ===== */
.cases-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
    margin-top: 50px;
}

.case-card {
    background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-light) 100%);
    border-radius: 16px;
    padding: 40px 30px;
    text-align: center;
    color: var(--color-white);
    transition: var(--transition);
}

.case-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-hover);
}

.case-icon {
    margin-bottom: 20px;
    opacity: 0.9;
}

.case-title {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 15px;
}

.case-desc {
    font-size: 0.95rem;
    opacity: 0.9;
    line-height: 1.6;
}

/* ===== 优势 ===== */
.advantages-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 30px;
    margin-top: 50px;
}

.advantage-item {
    text-align: center;
    padding: 30px 20px;
    background: var(--color-white);
    border-radius: 16px;
    box-shadow: var(--shadow);
    transition: var(--transition);
}

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

.advantage-icon {
    width: 60px;
    height: 60px;
    background: linear-gradient(135deg, var(--color-accent) 0%, var(--color-accent-light) 100%);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 20px;
    color: var(--color-white);
}

.advantage-title {
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--color-primary);
    margin-bottom: 10px;
}

.advantage-desc {
    font-size: 0.9rem;
    color: var(--color-text-light);
}

/* ===== 适合客户 ===== */
.clients-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 30px;
    margin-top: 50px;
}

.client-item {
    display: flex;
    align-items: center;
    gap: 20px;
    padding: 25px 30px;
    background: var(--color-bg);
    border-radius: 12px;
    transition: var(--transition);
}

.client-item:hover {
    background: var(--color-white);
    box-shadow: var(--shadow);
}

.client-icon {
    flex-shrink: 0;
    width: 50px;
    height: 50px;
    background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-light) 100%);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--color-white);
}

.client-text {
    font-size: 0.95rem;
    color: var(--color-text);
    font-weight: 500;
}

/* ===== 联系我们 ===== */
.contact-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 30px;
    margin-top: 50px;
}

.contact-item {
    display: flex;
    align-items: center;
    gap: 20px;
    padding: 25px 30px;
    background: var(--color-white);
    border-radius: 12px;
    box-shadow: var(--shadow);
    transition: var(--transition);
}

.contact-item:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-hover);
}

.contact-icon {
    flex-shrink: 0;
    width: 60px;
    height: 60px;
    background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-light) 100%);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--color-white);
}

.contact-info h4 {
    font-size: 0.9rem;
    color: var(--color-text-light);
    margin-bottom: 5px;
}

.contact-info a,
.contact-info p {
    font-size: 1rem;
    color: var(--color-primary);
    font-weight: 500;
}

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

/* ===== 页脚 ===== */
.footer {
    background: var(--color-primary-dark);
    color: var(--color-white);
    padding: 40px 20px;
    text-align: center;
}

.footer p {
    margin-bottom: 10px;
    font-size: 0.9rem;
    opacity: 0.9;
}

.footer a {
    color: var(--color-accent-light);
    transition: var(--transition);
}

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

/* ===== 动画 ===== */
.fade-init {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in {
    opacity: 1;
    transform: translateY(0);
}

/* ===== 响应式设计 ===== */
@media (max-width: 992px) {
    .hero-title {
        font-size: 2.5rem;
    }

    .process-timeline::before {
        display: none;
    }

    .ai-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 768px) {
    :root {
        --navbar-height: 60px;
    }

    .menu-toggle {
        display: block;
    }

    .nav-links {
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: var(--color-white);
        flex-direction: column;
        padding: 20px;
        gap: 0;
        box-shadow: var(--shadow);
        display: none;
    }

    .nav-links.active {
        display: flex;
    }

    .nav-links a {
        padding: 12px 0;
        border-bottom: 1px solid var(--color-bg);
    }

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

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

    .section {
        padding: 60px 0;
    }

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

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

    .process-timeline {
        flex-direction: column;
        align-items: center;
    }

    .step {
        min-width: 100%;
        max-width: 300px;
    }

    .ai-card-large {
        padding: 30px 20px;
    }
}

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

    .hero-buttons {
        flex-direction: column;
        align-items: center;
    }

    .btn {
        width: 100%;
        max-width: 250px;
    }

    .service-card,
    .ai-card,
    .case-card,
    .advantage-item {
        padding: 25px 20px;
    }
}