/* 现代 B2B 官网风 CSS */
:root {
    --b2b-primary: #1677FF; /* 科技蓝 */
    --b2b-primary-hover: #0958D9;
    --b2b-text-main: #1F2329;
    --b2b-text-sub: #646A73;
    --b2b-bg-light: #F4F5F7;
    --b2b-bg-white: #FFFFFF;
    --b2b-border: #DEE0E3;
    --radius-md: 6px;
    --radius-lg: 12px;
    --shadow-sm: 0 4px 12px rgba(0, 0, 0, 0.05);
    --shadow-lg: 0 12px 32px rgba(0, 0, 0, 0.08);
}

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

body {
    color: var(--b2b-text-main);
    line-height: 1.6;
    background-color: var(--b2b-bg-white);
    -webkit-font-smoothing: antialiased;
}

a {
    text-decoration: none;
    color: inherit;
    transition: color 0.2s;
}

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

.text-center { text-align: center; }
.mb-40 { margin-bottom: 40px; }
.bg-light { background-color: var(--b2b-bg-light); }

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 8px 20px;
    font-size: 14px;
    font-weight: 500;
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all 0.2s ease;
    border: 1px solid transparent;
}

.btn-lg {
    padding: 12px 28px;
    font-size: 16px;
}

.btn-block {
    display: flex;
    width: 100%;
}

.btn-primary {
    background-color: var(--b2b-primary);
    color: #fff;
}

.btn-primary:hover {
    background-color: var(--b2b-primary-hover);
    color: #fff;
}

.btn-outline {
    background-color: transparent;
    border-color: var(--b2b-primary);
    color: var(--b2b-primary);
}

.btn-outline:hover {
    background-color: #F0F5FF;
}

.btn-outline-light {
    background-color: transparent;
    border-color: #fff;
    color: #fff;
}

.btn-outline-light:hover {
    background-color: rgba(255,255,255,0.1);
}

.btn-text {
    color: var(--b2b-primary);
    background: transparent;
}

.btn-text:hover {
    color: var(--b2b-primary-hover);
    text-decoration: underline;
}

.btn .icon {
    margin-right: 8px;
    font-size: 18px;
}

/* Navbar */
.b2b-navbar {
    position: sticky;
    top: 0;
    background-color: rgba(255, 255, 255, 0.98);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--b2b-border);
    z-index: 1000;
}

.nav-container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 72px;
}

.brand-logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 22px;
    font-weight: 700;
    color: var(--b2b-text-main);
}

.logo-mark {
    width: 28px;
    height: 28px;
    background-color: var(--b2b-primary);
    border-radius: 6px;
}

.nav-links {
    display: flex;
    list-style: none;
    gap: 32px;
}

.nav-links a {
    font-size: 15px;
    color: var(--b2b-text-sub);
    font-weight: 500;
}

.nav-links a:hover, .nav-links a.active {
    color: var(--b2b-primary);
}

/* Hero Section */
.b2b-hero {
    padding: 80px 0;
    background: linear-gradient(180deg, #F8FAFF 0%, #FFFFFF 100%);
    overflow: hidden;
}

.page-hero {
    padding: 60px 0;
    background: var(--b2b-bg-light);
}

.hero-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
}

.trust-badge {
    display: inline-block;
    padding: 6px 16px;
    background-color: #E6F0FF;
    color: var(--b2b-primary);
    border-radius: 20px;
    font-size: 14px;
    font-weight: 600;
    margin-bottom: 24px;
}

.hero-content h1 {
    font-size: 48px;
    line-height: 1.2;
    font-weight: 800;
    margin-bottom: 24px;
    color: #141414;
}

.hero-desc {
    font-size: 18px;
    color: var(--b2b-text-sub);
    margin-bottom: 40px;
    line-height: 1.7;
}

/* Download Path Box (清晰展示下载路径) */
.download-path-box {
    background: #fff;
    padding: 24px;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--b2b-border);
}

.path-title {
    font-size: 14px;
    color: var(--b2b-text-sub);
    margin-bottom: 16px;
    font-weight: 500;
}

.path-buttons {
    display: flex;
    align-items: center;
    gap: 16px;
    flex-wrap: wrap;
}

.image-wrapper {
    position: relative;
}

.image-wrapper img, .rounded-img {
    width: 100%;
    border-radius: var(--radius-lg);
    display: block;
}

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

.floating-card {
    position: absolute;
    background: #fff;
    padding: 16px 24px;
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-lg);
    display: flex;
    flex-direction: column;
}

.floating-card.top-right {
    top: -20px;
    right: -20px;
}

.floating-card strong {
    color: var(--b2b-primary);
    font-size: 18px;
}

.floating-card span {
    color: var(--b2b-text-sub);
    font-size: 13px;
}

/* Data Section */
.b2b-data {
    padding: 40px 0;
    border-bottom: 1px solid var(--b2b-border);
}

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

.data-item .number {
    font-size: 36px;
    font-weight: 800;
    color: var(--b2b-text-main);
    margin-bottom: 8px;
}

.data-item .label {
    font-size: 15px;
    color: var(--b2b-text-sub);
}

/* Features */
.b2b-features {
    padding: 100px 0;
}

.section-title {
    text-align: center;
    margin-bottom: 60px;
}

.section-title h2 {
    font-size: 36px;
    font-weight: 700;
    margin-bottom: 16px;
}

.section-title p {
    font-size: 18px;
    color: var(--b2b-text-sub);
}

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

.feature-card {
    padding: 32px;
    background: var(--b2b-bg-light);
    border-radius: var(--radius-lg);
    transition: transform 0.3s ease;
}

.feature-card:hover {
    transform: translateY(-5px);
    background: #fff;
    box-shadow: var(--shadow-sm);
}

.icon-box {
    width: 48px;
    height: 48px;
    background: #fff;
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 24px;
    margin-bottom: 24px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.04);
}

.feature-card h3 {
    font-size: 20px;
    margin-bottom: 12px;
}

.feature-card p {
    color: var(--b2b-text-sub);
    font-size: 15px;
}

/* Solutions */
.b2b-solutions {
    padding: 100px 0;
    background-color: var(--b2b-bg-light);
}

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

.solution-card {
    background: #fff;
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-sm);
}

.card-img img {
    width: 100%;
    height: 200px;
    object-fit: cover;
}

.card-body {
    padding: 32px;
}

.card-body h3 {
    font-size: 22px;
    margin-bottom: 12px;
}

.card-body p {
    color: var(--b2b-text-sub);
    margin-bottom: 24px;
    font-size: 15px;
}

.link-more {
    color: var(--b2b-primary);
    font-weight: 500;
}

.link-more:hover {
    text-decoration: underline;
}

/* Download Paths (Download Page) */
.b2b-download-paths {
    padding: 80px 0;
}

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

.path-card {
    background: #fff;
    border: 1px solid var(--b2b-border);
    border-radius: var(--radius-lg);
    padding: 48px 32px;
    text-align: center;
    transition: box-shadow 0.3s;
}

.path-card:hover {
    box-shadow: var(--shadow-lg);
    border-color: transparent;
}

.card-icon {
    font-size: 56px;
    margin-bottom: 24px;
}

.path-card h3 {
    font-size: 24px;
    margin-bottom: 16px;
}

.path-card p {
    color: var(--b2b-text-sub);
    margin-bottom: 32px;
    font-size: 15px;
    min-height: 48px;
}

/* FAQ */
.b2b-faq {
    padding: 80px 0;
}

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

.faq-item {
    padding: 24px 0;
    border-bottom: 1px solid var(--b2b-border);
}

.faq-item h3 {
    font-size: 18px;
    margin-bottom: 12px;
    color: var(--b2b-text-main);
}

.faq-item p {
    color: var(--b2b-text-sub);
    font-size: 15px;
}

/* CTA */
.b2b-cta {
    padding: 100px 0;
    background-color: var(--b2b-primary);
    color: #fff;
    text-align: center;
}

.cta-container h2 {
    font-size: 40px;
    font-weight: 800;
    margin-bottom: 20px;
}

.cta-container p {
    font-size: 18px;
    opacity: 0.9;
    margin-bottom: 40px;
}

.cta-actions {
    display: flex;
    justify-content: center;
    gap: 20px;
}

.cta-actions .btn-primary {
    background-color: #fff;
    color: var(--b2b-primary);
}

.cta-actions .btn-primary:hover {
    background-color: var(--b2b-bg-light);
}

/* Footer */
.b2b-footer {
    background-color: #fff;
    padding: 80px 0 32px;
    border-top: 1px solid var(--b2b-border);
}

.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: 48px;
    margin-bottom: 60px;
}

.footer-brand p {
    margin-top: 16px;
    color: var(--b2b-text-sub);
    font-size: 14px;
}

.footer-links h4 {
    font-size: 16px;
    margin-bottom: 24px;
    color: var(--b2b-text-main);
}

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

.footer-links li {
    margin-bottom: 16px;
}

.footer-links a {
    color: var(--b2b-text-sub);
    font-size: 14px;
}

.footer-links a:hover {
    color: var(--b2b-primary);
}

.footer-bottom {
    border-top: 1px solid var(--b2b-border);
    padding-top: 32px;
    text-align: center;
    color: #8F959E;
    font-size: 13px;
}

@media (max-width: 992px) {
    .hero-grid, .data-wrapper, .feature-grid, .solution-grid, .path-grid, .footer-grid {
        grid-template-columns: 1fr;
        gap: 32px;
    }
    .nav-links { display: none; }
    .hero-content h1 { font-size: 36px; }
    .path-buttons { flex-direction: column; align-items: stretch; }
}