/* 全局重置与变量 */
:root {
    --primary: #007BFF;
    --primary-dark: #0056b3;
    --bg: #ffffff;
    --text: #1a1a2e;
    --card: #f8f9fa;
    --glass: rgba(255,255,255,0.7);
    --shadow: 0 4px 20px rgba(0,0,0,0.08);
    --radius: 16px;
    --transition: 0.3s ease;
    --gradient-start: #667eea;
    --gradient-end: #764ba2;
}
[data-theme="dark"] {
    --bg: #0d1117;
    --text: #c9d1d9;
    --card: #161b22;
    --glass: rgba(13,17,23,0.8);
    --shadow: 0 4px 20px rgba(0,0,0,0.4);
    --gradient-start: #0f0c29;
    --gradient-end: #302b63;
}
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}
body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: var(--bg);
    color: var(--text);
    line-height: 1.6;
    transition: background var(--transition), color var(--transition);
}
a {
    color: var(--primary);
    text-decoration: none;
}
img {
    display: block;
    max-width: 100%;
}
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}
/* 导航 */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: var(--glass);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid rgba(0,0,0,0.05);
    padding: 12px 0;
    transition: background var(--transition);
}
.nav-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
}
.logo {
    font-size: 1.6rem;
    font-weight: 800;
    color: var(--primary);
    letter-spacing: -0.5px;
    background: linear-gradient(135deg, var(--gradient-start), var(--gradient-end));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}
.nav-links {
    display: flex;
    gap: 28px;
    list-style: none;
}
.nav-links a {
    color: var(--text);
    font-weight: 500;
    transition: color var(--transition);
    position: relative;
}
.nav-links a::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: linear-gradient(135deg, var(--gradient-start), var(--gradient-end));
    transition: width var(--transition);
}
.nav-links a:hover::after {
    width: 100%;
}
.nav-right {
    display: flex;
    align-items: center;
    gap: 16px;
}
.theme-toggle {
    background: none;
    border: 2px solid var(--primary);
    color: var(--primary);
    padding: 6px 14px;
    border-radius: 30px;
    cursor: pointer;
    font-size: 0.9rem;
    font-weight: 600;
    transition: all var(--transition);
}
.theme-toggle:hover {
    background: var(--primary);
    color: white;
}
.mobile-menu-btn {
    display: none;
    background: none;
    border: none;
    font-size: 1.8rem;
    color: var(--text);
    cursor: pointer;
}
.search-box {
    display: flex;
    align-items: center;
    background: var(--card);
    border-radius: 30px;
    padding: 4px 12px;
    border: 1px solid rgba(0,0,0,0.05);
}
.search-box input {
    border: none;
    background: transparent;
    padding: 6px 8px;
    outline: none;
    color: var(--text);
    width: 140px;
}
.search-box button {
    background: none;
    border: none;
    color: var(--primary);
    cursor: pointer;
    font-size: 1.1rem;
}
/* 面包屑 */
.breadcrumb {
    padding: 100px 0 10px;
    font-size: 0.9rem;
    color: #888;
}
.breadcrumb a {
    color: var(--primary);
}
/* Hero Banner */
.hero {
    position: relative;
    padding: 120px 0 80px;
    background: linear-gradient(135deg, var(--gradient-start) 0%, var(--gradient-end) 100%);
    color: white;
    overflow: hidden;
}
.hero::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle, rgba(255,255,255,0.1) 0%, transparent 70%);
    animation: heroGlow 8s ease-in-out infinite alternate;
}
@keyframes heroGlow {
    0% { transform: translate(0, 0); }
    100% { transform: translate(-20%, -20%); }
}
.hero-slider {
    display: flex;
    transition: transform 0.5s ease;
}
.hero-slide {
    min-width: 100%;
    padding: 40px 20px;
    text-align: center;
    position: relative;
    z-index: 1;
}
.hero h1 {
    font-size: 3.2rem;
    font-weight: 800;
    margin-bottom: 20px;
    letter-spacing: -1px;
    text-shadow: 0 2px 10px rgba(0,0,0,0.2);
}
.hero p {
    font-size: 1.2rem;
    max-width: 700px;
    margin: 0 auto 30px;
    opacity: 0.9;
}
.hero .btn {
    display: inline-block;
    padding: 14px 40px;
    background: white;
    color: var(--primary);
    border-radius: 50px;
    font-weight: 700;
    font-size: 1rem;
    transition: transform var(--transition), box-shadow var(--transition);
    box-shadow: 0 4px 15px rgba(0,0,0,0.2);
}
.hero .btn:hover {
    transform: scale(1.05);
    box-shadow: 0 6px 20px rgba(0,0,0,0.3);
}
.hero-dots {
    display: flex;
    justify-content: center;
    gap: 10px;
    margin-top: 30px;
    position: relative;
    z-index: 1;
}
.hero-dots span {
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background: rgba(255,255,255,0.4);
    cursor: pointer;
    transition: background var(--transition), transform var(--transition);
}
.hero-dots span.active {
    background: white;
    transform: scale(1.3);
}
/* 通用section */
.section {
    padding: 80px 0;
}
.section-title {
    text-align: center;
    margin-bottom: 50px;
}
.section-title h2 {
    font-size: 2.4rem;
    font-weight: 700;
    color: var(--text);
    position: relative;
    display: inline-block;
}
.section-title h2::after {
    content: '';
    display: block;
    width: 60px;
    height: 4px;
    background: linear-gradient(135deg, var(--gradient-start), var(--gradient-end));
    margin: 10px auto 0;
    border-radius: 2px;
}
.section-title p {
    color: #888;
    margin-top: 8px;
}
/* 卡片网格 */
.grid-3 {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 30px;
}
.grid-4 {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 24px;
}
.card {
    background: var(--card);
    border-radius: var(--radius);
    padding: 30px 24px;
    box-shadow: var(--shadow);
    transition: transform var(--transition), box-shadow var(--transition);
    backdrop-filter: blur(4px);
    -webkit-backdrop-filter: blur(4px);
    border: 1px solid rgba(0,0,0,0.03);
    position: relative;
    overflow: hidden;
}
.card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(135deg, var(--gradient-start), var(--gradient-end));
    opacity: 0;
    transition: opacity var(--transition);
}
.card:hover::before {
    opacity: 1;
}
.card:hover {
    transform: translateY(-6px);
    box-shadow: 0 12px 40px rgba(0,0,0,0.12);
}
.card-icon {
    width: 48px;
    height: 48px;
    margin-bottom: 16px;
}
.card h3 {
    font-size: 1.3rem;
    margin-bottom: 10px;
}
.card p {
    color: #666;
}
/* 数据展示 */
.stats {
    background: var(--card);
    padding: 60px 0;
    position: relative;
}
.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 30px;
    text-align: center;
}
.stat-item .num {
    font-size: 2.8rem;
    font-weight: 800;
    color: var(--primary);
    background: linear-gradient(135deg, var(--gradient-start), var(--gradient-end));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}
.stat-item p {
    color: #888;
    margin-top: 4px;
}
/* 案例/客户 logo */
.client-logos {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 30px;
    padding: 20px 0;
}
.client-logos svg {
    width: 100px;
    height: 40px;
    opacity: 0.6;
    transition: opacity var(--transition), transform var(--transition);
}
.client-logos svg:hover {
    opacity: 1;
    transform: scale(1.05);
}
/* FAQ */
.faq-item {
    border-bottom: 1px solid rgba(0,0,0,0.06);
    padding: 16px 0;
    cursor: pointer;
    transition: background var(--transition);
}
.faq-item:hover {
    background: rgba(0,0,0,0.02);
}
.faq-question {
    display: flex;
    justify-content: space-between;
    font-weight: 600;
    font-size: 1.1rem;
    user-select: none;
}
.faq-question span {
    transition: transform var(--transition);
}
.faq-item.open .faq-question span {
    transform: rotate(45deg);
}
.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.4s ease, padding var(--transition);
    padding-top: 0;
    color: #666;
}
.faq-item.open .faq-answer {
    max-height: 300px;
    padding-top: 8px;
}
/* 联系 */
.contact-info {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 24px;
}
.contact-info div {
    padding: 16px;
    background: var(--card);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    transition: transform var(--transition);
}
.contact-info div:hover {
    transform: translateY(-3px);
}
/* Footer */
.footer {
    background: var(--card);
    padding: 40px 0 20px;
    margin-top: 40px;
    border-top: 1px solid rgba(0,0,0,0.05);
}
.footer-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
    gap: 30px;
}
.footer h4 {
    margin-bottom: 12px;
    color: var(--text);
}
.footer a {
    display: block;
    color: #888;
    margin-bottom: 6px;
    transition: color var(--transition);
}
.footer a:hover {
    color: var(--primary);
}
.footer-bottom {
    text-align: center;
    padding-top: 20px;
    border-top: 1px solid rgba(0,0,0,0.05);
    margin-top: 20px;
    font-size: 0.85rem;
    color: #888;
}
.back-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 48px;
    height: 48px;
    background: linear-gradient(135deg, var(--gradient-start), var(--gradient-end));
    color: white;
    border: none;
    border-radius: 50%;
    font-size: 1.4rem;
    cursor: pointer;
    display: none;
    align-items: center;
    justify-content: center;
    box-shadow: 0 4px 12px rgba(0,0,0,0.2);
    z-index: 999;
    transition: opacity var(--transition), transform var(--transition);
}
.back-top.show {
    display: flex;
}
.back-top:hover {
    transform: scale(1.1);
}
/* 响应式 */
@media (max-width: 768px) {
    .nav-links {
        display: none;
        flex-direction: column;
        position: absolute;
        top: 60px;
        left: 0;
        right: 0;
        background: var(--bg);
        padding: 20px;
        box-shadow: var(--shadow);
        border-radius: 0 0 var(--radius) var(--radius);
    }
    .nav-links.open {
        display: flex;
    }
    .mobile-menu-btn {
        display: block;
    }
    .hero h1 {
        font-size: 2rem;
    }
    .section-title h2 {
        font-size: 1.8rem;
    }
    .search-box input {
        width: 100px;
    }
    .grid-3, .grid-4 {
        grid-template-columns: 1fr;
    }
    .stats-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    .hero {
        padding: 100px 0 60px;
    }
    .breadcrumb {
        padding: 80px 0 10px;
    }
}
@media (max-width: 480px) {
    .hero h1 {
        font-size: 1.6rem;
    }
    .hero p {
        font-size: 1rem;
    }
    .section-title h2 {
        font-size: 1.5rem;
    }
}
/* 滚动动画 */
.fade-up {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}
.fade-up.visible {
    opacity: 1;
    transform: translateY(0);
}
/* 额外装饰 */
.section:nth-child(even) {
    background: var(--card);
}
.card {
    position: relative;
}
.card::after {
    content: '';
    position: absolute;
    bottom: 0;
    right: 0;
    width: 60px;
    height: 60px;
    background: radial-gradient(circle, rgba(102,126,234,0.05) 0%, transparent 70%);
    border-radius: 50%;
    pointer-events: none;
}
/* 暗色模式微调 */
[data-theme="dark"] .card {
    border-color: rgba(255,255,255,0.05);
}
[data-theme="dark"] .faq-item:hover {
    background: rgba(255,255,255,0.02);
}
[data-theme="dark"] .search-box {
    border-color: rgba(255,255,255,0.1);
}