* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: "PingFang SC", "Microsoft YaHei", "Segoe UI", sans-serif;
    background: linear-gradient(135deg, #f5f7fa 0%, #e4edf9 100%);
    color: #333;
    line-height: 1.6;
    min-height: 100vh;
}

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

header,
nav.site-nav {
    background: rgba(255, 255, 255, 0.92);
    backdrop-filter: blur(10px);
    padding: 0.9rem 0;
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: 0 2px 15px rgba(0, 0, 0, 0.05);
}

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

.logo {
    display: flex;
    align-items: center;
    text-decoration: none;
    color: inherit;
}

.logo img {
    height: 40px;
    margin-right: 10px;
}

.logo h2,
.logo span.brand {
    font-size: 1.45rem;
    color: #4a6cf7;
    font-weight: 600;
}

.nav-links {
    display: flex;
    list-style: none;
    gap: 1.6rem;
    flex-wrap: wrap;
}

.nav-links a {
    text-decoration: none;
    color: #555;
    font-weight: 500;
    transition: color 0.3s;
}

.nav-links a:hover,
.nav-links a.active {
    color: #4a6cf7;
}

.hero {
    padding: 5.5rem 0 4rem;
    background: linear-gradient(135deg, #eef2ff 0%, #e4edf9 100%);
}

.hero-content {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 3rem;
}

.hero-text {
    flex: 1;
}

.hero-text h1 {
    font-size: 2.9rem;
    color: #2c3e50;
    margin-bottom: 1.2rem;
    line-height: 1.25;
}

.hero-text p {
    font-size: 1.15rem;
    color: #667788;
    margin-bottom: 1.8rem;
    max-width: 560px;
}

.hero-visual-wrap {
    flex: 1;
    display: flex;
    justify-content: center;
}

.hero-visual {
    width: 300px;
    height: 300px;
    border-radius: 20px;
    background: linear-gradient(145deg, #4a6cf7, #6a11cb);
    display: flex;
    align-items: center;
    justify-content: center;
    color: #fff;
    font-size: 4.5rem;
    box-shadow: 0 20px 40px rgba(74, 108, 247, 0.28);
    animation: float 6s ease-in-out infinite;
}

@keyframes float {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-18px); }
}

.btn-download {
    display: inline-block;
    background: linear-gradient(90deg, #4a6cf7, #6a11cb);
    color: #fff;
    padding: 0.95rem 2.4rem;
    border-radius: 50px;
    text-decoration: none;
    font-weight: 600;
    font-size: 1.05rem;
    transition: transform 0.3s, box-shadow 0.3s;
    box-shadow: 0 10px 20px rgba(74, 108, 247, 0.3);
    border: none;
    cursor: pointer;
}

.btn-download:hover {
    transform: translateY(-3px);
    box-shadow: 0 15px 25px rgba(74, 108, 247, 0.4);
}

.btn-outline {
    background: #fff;
    color: #4a6cf7;
    border: 2px solid #4a6cf7;
    box-shadow: none;
}

.btn-outline:hover {
    background: #f0f4ff;
}

.section {
    padding: 4.5rem 0;
}

.section-title {
    text-align: center;
    margin-bottom: 2.8rem;
}

.section-title h2 {
    font-size: 2.3rem;
    color: #2c3e50;
    margin-bottom: 0.8rem;
    position: relative;
    display: inline-block;
}

.section-title h2::after {
    content: "";
    position: absolute;
    bottom: -10px;
    left: 50%;
    transform: translateX(-50%);
    width: 72px;
    height: 4px;
    background: linear-gradient(90deg, #4a6cf7, #6a11cb);
    border-radius: 2px;
}

.section-title p {
    color: #7f8c8d;
    font-size: 1.05rem;
    max-width: 620px;
    margin: 1.4rem auto 0;
}

.features-grid,
.sync-grid,
.platform-grid,
.download-grid,
.req-grid,
.testimonial-grid,
.support-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 1.5rem;
}

.feature-card,
.sync-card,
.download-card,
.req-card,
.testimonial-card,
.support-card,
.platform-item {
    background: #fff;
    border-radius: 15px;
    padding: 1.8rem;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.05);
    text-align: center;
    transition: transform 0.3s, box-shadow 0.3s;
}

.feature-card:hover,
.sync-card:hover,
.download-card:hover,
.platform-item:hover {
    transform: translateY(-6px);
    box-shadow: 0 15px 40px rgba(74, 108, 247, 0.12);
}

.feature-icon,
.sync-icon,
.platform-icon,
.support-icon {
    width: 68px;
    height: 68px;
    margin: 0 auto 1rem;
    border-radius: 50%;
    background: linear-gradient(135deg, #4a6cf7, #6a11cb);
    color: #fff;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.7rem;
}

.feature-card h3,
.sync-card h3,
.download-card h3,
.platform-item h3,
.req-card h3,
.support-card h3 {
    margin-bottom: 0.7rem;
    color: #2c3e50;
}

.feature-card p,
.sync-card p,
.download-card p,
.platform-item p,
.support-card p {
    color: #667788;
    font-size: 0.98rem;
}

.platforms {
    background: rgba(255, 255, 255, 0.55);
}

.req-card {
    text-align: left;
}

.req-list {
    list-style: none;
    margin-top: 0.8rem;
}

.req-list li {
    padding: 0.45rem 0;
    border-bottom: 1px solid #eef1f6;
    color: #555;
    font-size: 0.95rem;
}

.req-list li:last-child {
    border-bottom: none;
}

.testimonials {
    background: transparent;
}

.testimonial-grid .testimonial-card {
    text-align: left;
}

.testimonial-header {
    display: flex;
    align-items: center;
    gap: 0.9rem;
    margin-bottom: 1rem;
}

.testimonial-avatar {
    width: 44px;
    height: 44px;
    border-radius: 50%;
    background: linear-gradient(135deg, #4a6cf7, #6a11cb);
    color: #fff;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
}

.testimonial-info h4 {
    color: #2c3e50;
}

.testimonial-info p {
    color: #95a5a6;
    font-size: 0.88rem;
}

.faq-container {
    max-width: 860px;
    margin: 0 auto;
}

.faq-item {
    margin-bottom: 0.9rem;
    border-radius: 10px;
    overflow: hidden;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.05);
}

.faq-question {
    background: #fff;
    padding: 1.2rem 1.4rem;
    cursor: pointer;
    font-weight: 600;
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 1rem;
}

.faq-answer {
    background: #f8f9ff;
    padding: 0 1.4rem;
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.35s ease, padding 0.35s ease;
}

.faq-answer.active {
    padding: 1.2rem 1.4rem;
    max-height: 1400px;
}

.page-hero {
    text-align: center;
    padding: 4.5rem 0 2.5rem;
}

.page-hero h1 {
    font-size: 2.5rem;
    color: #2c3e50;
    margin-bottom: 0.9rem;
}

.page-hero p {
    color: #667788;
    max-width: 640px;
    margin: 0 auto 1.5rem;
}

.platform-tabs {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 0.8rem;
    margin-bottom: 1.5rem;
}

.platform-btn {
    border: 1px solid #dbe3ff;
    background: #fff;
    color: #4a5568;
    padding: 0.7rem 1.3rem;
    border-radius: 999px;
    cursor: pointer;
    font-weight: 600;
    transition: all 0.25s;
}

.platform-btn.active,
.platform-btn:hover {
    background: linear-gradient(90deg, #4a6cf7, #6a11cb);
    color: #fff;
    border-color: transparent;
}

.download-card .meta {
    color: #7f8c8d;
    font-size: 0.92rem;
    margin: 0.35rem 0;
}

.download-card .btn-download {
    margin-top: 1rem;
    padding: 0.75rem 1.6rem;
    font-size: 0.95rem;
}

.article-list {
    display: grid;
    gap: 1.3rem;
    max-width: 900px;
    margin: 0 auto;
}

.article-item {
    background: #fff;
    border-radius: 15px;
    padding: 1.7rem 1.9rem;
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.05);
    transition: transform 0.3s;
}

.article-item:hover {
    transform: translateY(-4px);
}

.article-item h3 a {
    color: #2c3e50;
    text-decoration: none;
}

.article-item h3 a:hover {
    color: #4a6cf7;
}

.article-meta {
    color: #95a5a6;
    font-size: 0.9rem;
    margin: 0.55rem 0 0.7rem;
}

.article-item p {
    color: #555;
}

.article-page {
    max-width: 820px;
    margin: 0 auto;
    background: #fff;
    border-radius: 15px;
    padding: 2.4rem;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.05);
}

.article-page h1 {
    font-size: 1.95rem;
    color: #2c3e50;
    margin-bottom: 0.9rem;
}

.article-page .article-meta {
    margin-bottom: 1.4rem;
    padding-bottom: 1rem;
    border-bottom: 1px solid #eee;
}

.article-body h2 {
    font-size: 1.3rem;
    color: #2c3e50;
    margin: 1.6rem 0 0.75rem;
}

.article-body p {
    margin-bottom: 1rem;
    color: #444;
}

.article-body ul {
    margin: 0.4rem 0 1.1rem 1.3rem;
    color: #444;
}

.article-body li {
    margin-bottom: 0.4rem;
}

.article-cta {
    margin-top: 2.2rem;
    padding: 1.4rem;
    background: #f8f9ff;
    border-radius: 12px;
    text-align: center;
}

.update-badge {
    display: inline-block;
    background: #eef2ff;
    color: #4a6cf7;
    font-size: 0.85rem;
    padding: 0.22rem 0.7rem;
    border-radius: 20px;
    margin-left: 0.4rem;
}

.sitemap-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 1.4rem;
    max-width: 960px;
    margin: 0 auto;
}

.sitemap-card {
    background: #fff;
    border-radius: 15px;
    padding: 1.6rem 1.8rem;
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.05);
    text-align: left;
}

.sitemap-card h3 {
    color: #2c3e50;
    margin-bottom: 0.9rem;
}

.sitemap-card ul {
    list-style: none;
}

.sitemap-card li {
    margin-bottom: 0.55rem;
}

.sitemap-card a {
    color: #4a6cf7;
    text-decoration: none;
}

.sitemap-card a:hover {
    text-decoration: underline;
}

footer {
    background: #2c3e50;
    color: #fff;
    padding: 3rem 0 2rem;
    margin-top: 2rem;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
}

.footer-section h3 {
    margin-bottom: 1.1rem;
    font-size: 1.05rem;
}

.footer-section p {
    color: #bdc3c7;
    font-size: 0.95rem;
}

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

.footer-section ul li {
    margin-bottom: 0.65rem;
}

.footer-section ul li a {
    color: #bdc3c7;
    text-decoration: none;
    transition: color 0.3s;
}

.footer-section ul li a:hover {
    color: #fff;
}

.copyright {
    text-align: center;
    padding-top: 1.4rem;
    border-top: 1px solid #34495e;
    color: #bdc3c7;
    font-size: 0.9rem;
}

@media (max-width: 768px) {
    .hero-content {
        flex-direction: column;
        text-align: center;
    }

    .hero-text p {
        margin-left: auto;
        margin-right: auto;
    }

    .hero-text h1 {
        font-size: 2.1rem;
    }

    .hero-visual {
        width: 220px;
        height: 220px;
        font-size: 3.4rem;
    }

    .nav-content {
        flex-direction: column;
        gap: 0.8rem;
    }

    .nav-links {
        justify-content: center;
        gap: 0.9rem 1.1rem;
    }

    .section-title h2 {
        font-size: 1.85rem;
    }

    .article-page {
        padding: 1.4rem;
    }
}