/* PC端客户端下载风，稳定安全 CSS */
:root {
    --pc-primary: #0052D9; /* 安全可靠的深蓝 */
    --pc-primary-hover: #003CAB;
    --pc-safe: #00A870; /* 安全绿 */
    --pc-dark: #001A4D;
    --text-main: #1C2433;
    --text-sub: #4B5B76;
    --text-light: #8A9Baf;
    --bg-white: #FFFFFF;
    --bg-gray: #F2F5F8;
    --bg-blue-light: #EBF2FF;
    --border-color: #DDE4EE;
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --shadow-sm: 0 2px 6px rgba(0, 26, 77, 0.06);
    --shadow-md: 0 6px 16px rgba(0, 26, 77, 0.1);
    --shadow-lg: 0 12px 32px rgba(0, 26, 77, 0.15);
    --transition: all 0.25s ease-in-out;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}

body {
    color: var(--text-main);
    line-height: 1.6;
    background-color: var(--bg-white);
    -webkit-font-smoothing: antialiased;
}

a {
    text-decoration: none;
    color: inherit;
    transition: var(--transition);
}

ul {
    list-style: none;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
}

/* 按钮样式 - 强调下载与安全 */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 10px 24px;
    font-size: 15px;
    font-weight: 600;
    border-radius: var(--radius-sm);
    cursor: pointer;
    border: 1px solid transparent;
    transition: var(--transition);
}

.btn-lg {
    padding: 14px 36px;
    font-size: 18px;
    border-radius: var(--radius-md);
}

.btn-primary {
    background-color: var(--pc-primary);
    color: #ffffff;
    box-shadow: 0 4px 10px rgba(0, 82, 217, 0.3);
}

.btn-primary:hover {
    background-color: var(--pc-primary-hover);
    box-shadow: 0 6px 16px rgba(0, 82, 217, 0.4);
    transform: translateY(-1px);
}

.btn-safe {
    background-color: var(--pc-safe);
    color: #ffffff;
    box-shadow: 0 4px 10px rgba(0, 168, 112, 0.3);
}

.btn-safe:hover {
    background-color: #008f5e;
    box-shadow: 0 6px 16px rgba(0, 168, 112, 0.4);
    transform: translateY(-1px);
}

.btn-outline {
    background-color: transparent;
    border-color: var(--border-color);
    color: var(--text-main);
}

.btn-outline:hover {
    background-color: var(--bg-gray);
    border-color: var(--text-sub);
}

/* 导航栏 - 稳重专业 */
.pc-nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background-color: var(--bg-white);
    border-bottom: 1px solid var(--border-color);
    z-index: 1000;
    box-shadow: var(--shadow-sm);
}

.nav-wrapper {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 70px;
}

.brand-logo {
    display: flex;
    align-items: center;
    gap: 12px;
}

.logo-icon {
    width: 34px;
    height: 34px;
    background-color: var(--pc-primary);
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: #fff;
    font-weight: bold;
    font-size: 18px;
}

.logo-text {
    font-size: 22px;
    font-weight: 700;
    color: var(--pc-dark);
    letter-spacing: -0.5px;
}

.nav-menu {
    display: flex;
    gap: 32px;
}

.nav-menu a {
    font-size: 15px;
    color: var(--text-sub);
    font-weight: 500;
}

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

.nav-actions {
    display: flex;
    gap: 16px;
    align-items: center;
}

/* Hero 首屏 - PC客户端下载风 */
.pc-hero {
    padding: 130px 0 70px;
    background: linear-gradient(135deg, var(--bg-blue-light) 0%, #ffffff 100%);
    position: relative;
    overflow: hidden;
    border-bottom: 1px solid var(--border-color);
}

.hero-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 50px;
    align-items: center;
}

.hero-tag {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 4px 12px;
    background-color: rgba(0, 168, 112, 0.1);
    color: var(--pc-safe);
    border-radius: 4px;
    font-size: 13px;
    font-weight: 700;
    margin-bottom: 24px;
    border: 1px solid rgba(0, 168, 112, 0.2);
}

.hero-tag::before {
    content: '🛡️';
    font-size: 14px;
}

.pc-hero h1 {
    font-size: 46px;
    line-height: 1.25;
    font-weight: 800;
    margin-bottom: 20px;
    color: var(--pc-dark);
    letter-spacing: -1px;
}

.hero-desc {
    font-size: 18px;
    color: var(--text-sub);
    margin-bottom: 36px;
    line-height: 1.6;
}

.hero-actions {
    display: flex;
    gap: 16px;
    margin-bottom: 24px;
}

.hero-meta {
    font-size: 13px;
    color: var(--text-light);
    display: flex;
    gap: 24px;
    background: var(--bg-white);
    padding: 12px 20px;
    border-radius: var(--radius-sm);
    border: 1px solid var(--border-color);
    display: inline-flex;
}

.hero-meta span {
    display: flex;
    align-items: center;
    gap: 6px;
}

.hero-meta span::before {
    content: '✓';
    color: var(--pc-safe);
    font-weight: bold;
}

.hero-visual {
    position: relative;
}

.hero-visual img {
    width: 100%;
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-lg);
    border: 1px solid var(--border-color);
}

/* 数据背书区 */
.pc-data {
    padding: 50px 0;
    background-color: var(--bg-white);
    border-bottom: 1px solid var(--border-color);
}

.data-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
    text-align: center;
}

.data-num {
    font-size: 36px;
    font-weight: 800;
    color: var(--pc-primary);
    margin-bottom: 8px;
}

.data-label {
    font-size: 15px;
    color: var(--text-sub);
    font-weight: 500;
}

/* 通用区块标题 */
.section-header {
    text-align: center;
    margin-bottom: 50px;
}

.section-header h2 {
    font-size: 32px;
    font-weight: 700;
    color: var(--pc-dark);
    margin-bottom: 16px;
}

.section-header p {
    font-size: 16px;
    color: var(--text-sub);
}

/* 核心功能区 */
.pc-features {
    padding: 90px 0;
    background-color: var(--bg-gray);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.feature-card {
    background-color: var(--bg-white);
    padding: 36px 28px;
    border-radius: var(--radius-md);
    border: 1px solid var(--border-color);
    transition: var(--transition);
}

.feature-card:hover {
    box-shadow: var(--shadow-md);
    border-color: var(--pc-primary);
    transform: translateY(-2px);
}

.f-icon {
    width: 52px;
    height: 52px;
    background-color: var(--bg-blue-light);
    color: var(--pc-primary);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 24px;
    margin-bottom: 20px;
}

.feature-card h3 {
    font-size: 18px;
    margin-bottom: 12px;
    font-weight: 600;
    color: var(--pc-dark);
}

.feature-card p {
    color: var(--text-sub);
    font-size: 14px;
    line-height: 1.6;
}

/* 行业解决方案区 */
.pc-solutions {
    padding: 90px 0;
    background-color: var(--bg-white);
}

.solutions-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 32px;
}

.solution-card {
    background-color: var(--bg-white);
    border-radius: var(--radius-md);
    overflow: hidden;
    border: 1px solid var(--border-color);
    transition: var(--transition);
}

.solution-card:hover {
    box-shadow: var(--shadow-md);
}

.s-img {
    height: 190px;
    overflow: hidden;
}

.s-img img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.4s ease;
}

.solution-card:hover .s-img img {
    transform: scale(1.05);
}

.s-content {
    padding: 28px;
}

.s-content h3 {
    font-size: 18px;
    margin-bottom: 10px;
    font-weight: 600;
    color: var(--pc-dark);
}

.s-content p {
    font-size: 14px;
    color: var(--text-sub);
}

/* 底部 CTA - 安全下载引导 */
.pc-cta {
    padding: 80px 0;
    background-color: var(--pc-dark);
    color: #ffffff;
    text-align: center;
    background-image: radial-gradient(circle at center, #002b80 0%, var(--pc-dark) 100%);
}

.pc-cta h2 {
    font-size: 36px;
    font-weight: 700;
    margin-bottom: 20px;
}

.pc-cta p {
    font-size: 16px;
    color: var(--text-light);
    margin-bottom: 36px;
}

.cta-actions {
    display: flex;
    justify-content: center;
    gap: 16px;
}

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

.btn-white:hover {
    background-color: var(--bg-gray);
}

/* 下载页专用 - 突出PC端与安全 */
.download-page {
    padding: 120px 0 80px;
    background-color: var(--bg-gray);
}

.dl-header {
    text-align: center;
    margin-bottom: 50px;
}

.dl-header h1 {
    font-size: 38px;
    color: var(--pc-dark);
    margin-bottom: 16px;
}

.dl-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.dl-card {
    background-color: var(--bg-white);
    border-radius: var(--radius-md);
    padding: 40px 24px;
    text-align: center;
    border: 1px solid var(--border-color);
    transition: var(--transition);
    position: relative;
}

.dl-card:hover {
    box-shadow: var(--shadow-md);
    transform: translateY(-4px);
}

.dl-card.primary {
    border: 2px solid var(--pc-primary);
    box-shadow: var(--shadow-sm);
}

.dl-badge {
    position: absolute;
    top: -12px;
    left: 50%;
    transform: translateX(-50%);
    background-color: var(--pc-primary);
    color: #fff;
    padding: 4px 12px;
    border-radius: 4px;
    font-size: 12px;
    font-weight: 600;
}

.d-icon {
    font-size: 52px;
    margin-bottom: 20px;
}

.dl-card h3 {
    font-size: 22px;
    margin-bottom: 12px;
    color: var(--pc-dark);
}

.dl-card p {
    color: var(--text-sub);
    margin-bottom: 28px;
    font-size: 14px;
    min-height: 42px;
}

.safe-note {
    display: block;
    font-size: 12px;
    color: var(--pc-safe);
    margin-top: 12px;
}

/* 帮助中心专用 */
.help-page {
    padding: 120px 0 80px;
    background-color: var(--bg-white);
}

.faq-container {
    max-width: 800px;
    margin: 0 auto;
}

.faq-item {
    background-color: var(--bg-white);
    border: 1px solid var(--border-color);
    padding: 24px 32px;
    border-radius: var(--radius-md);
    margin-bottom: 16px;
    transition: var(--transition);
}

.faq-item:hover {
    border-color: var(--pc-primary);
    box-shadow: var(--shadow-sm);
}

.faq-item h3 {
    font-size: 16px;
    margin-bottom: 12px;
    color: var(--pc-dark);
    font-weight: 600;
}

.faq-item p {
    font-size: 14px;
    color: var(--text-sub);
    line-height: 1.6;
}

/* 页脚 */
.pc-footer {
    background-color: var(--bg-white);
    padding: 60px 0 24px;
    border-top: 1px solid var(--border-color);
}

.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: 40px;
    margin-bottom: 48px;
}

.footer-brand .logo-text {
    color: var(--pc-dark);
}

.footer-brand p {
    margin-top: 16px;
    font-size: 14px;
    color: var(--text-sub);
    line-height: 1.6;
}

.footer-links h4 {
    font-size: 15px;
    margin-bottom: 20px;
    font-weight: 600;
    color: var(--pc-dark);
}

.footer-links a {
    display: block;
    font-size: 14px;
    color: var(--text-sub);
    margin-bottom: 12px;
}

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

.footer-bottom {
    border-top: 1px solid var(--border-color);
    padding-top: 24px;
    text-align: center;
    font-size: 13px;
    color: var(--text-light);
}

@media (max-width: 900px) {
    .hero-grid, .features-grid, .solutions-grid, .dl-grid, .footer-grid {
        grid-template-columns: 1fr;
        gap: 24px;
    }
    .data-grid {
        grid-template-columns: 1fr 1fr;
    }
    .nav-menu { display: none; }
}