:root {
    --primary-color: #0052d9; /* 企业蓝 */
    --primary-hover: #003cab;
    --text-main: #111111;
    --text-regular: #333333;
    --text-muted: #5e6d82;
    --bg-page: #f4f6f8;
    --bg-white: #ffffff;
    --border-color: #e4e7ed;
    --nav-height: 72px;
}

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

body {
    font-family: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Helvetica, Arial, sans-serif;
    color: var(--text-regular);
    background-color: var(--bg-white);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
}

a {
    text-decoration: none;
    color: inherit;
    transition: color 0.3s;
}

ul {
    list-style: none;
}

/* Navigation - Enterprise Style */
.navbar {
    position: fixed;
    top: 0;
    width: 100%;
    height: var(--nav-height);
    background-color: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    z-index: 9999;
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
    border-bottom: 1px solid var(--border-color);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    height: 100%;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0 24px;
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: 10px;
}

.nav-logo img {
    height: 36px;
    vertical-align: middle;
}

.logo-text {
    font-size: 24px;
    font-weight: 600;
    color: var(--text-main);
    letter-spacing: 1px;
}

.nav-links {
    display: flex;
    gap: 36px;
    align-items: center;
}

.nav-links a {
    font-size: 16px;
    color: var(--text-main);
    font-weight: 500;
}

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

.nav-actions .btn {
    padding: 8px 24px;
    font-size: 14px;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 14px 32px;
    border-radius: 4px; /* 企业级更倾向于小圆角或直角 */
    font-size: 16px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s ease;
}

.btn-primary {
    background-color: var(--primary-color);
    color: #fff;
    border: 1px solid var(--primary-color);
}

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

.btn-secondary {
    background-color: transparent;
    color: var(--primary-color);
    border: 1px solid var(--primary-color);
}

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

/* Enterprise Hero Section (Centered Large Image) */
.hero-enterprise {
    padding-top: calc(var(--nav-height) + 80px);
    padding-bottom: 60px;
    text-align: center;
    background: linear-gradient(180deg, #f4f8ff 0%, #ffffff 100%);
    overflow: hidden;
}

.hero-enterprise h1 {
    font-size: 52px;
    font-weight: 700;
    color: var(--text-main);
    margin-bottom: 24px;
    letter-spacing: -0.5px;
}

.hero-enterprise p {
    font-size: 20px;
    color: var(--text-muted);
    margin-bottom: 40px;
    max-width: 700px;
    margin-left: auto;
    margin-right: auto;
}

.hero-cta {
    display: flex;
    justify-content: center;
    gap: 20px;
    margin-bottom: 60px;
}

.hero-image-wrapper {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
    perspective: 1000px;
}

.hero-image-wrapper img {
    width: 100%;
    height: auto;
    border-radius: 12px;
    box-shadow: 0 30px 60px rgba(0, 82, 217, 0.15), 0 0 1px rgba(0,0,0,0.1);
    border: 1px solid rgba(0,0,0,0.05);
    transform: translateY(0);
    transition: transform 0.5s ease;
}

.hero-image-wrapper img:hover {
    transform: translateY(-5px);
}

/* Common Section Styles */
.section {
    padding: 100px 24px;
}

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

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

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

.section-header h2 {
    font-size: 36px;
    color: var(--text-main);
    margin-bottom: 16px;
}

.section-header p {
    font-size: 18px;
    color: var(--text-muted);
}

/* Features Grid */
.feature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 40px;
}

.feature-card {
    background: var(--bg-white);
    padding: 40px 30px;
    border-radius: 8px;
    box-shadow: 0 4px 20px rgba(0,0,0,0.03);
    border: 1px solid var(--border-color);
    transition: all 0.3s ease;
}

.feature-card:hover {
    box-shadow: 0 10px 30px rgba(0, 82, 217, 0.1);
    transform: translateY(-5px);
}

.feature-icon {
    font-size: 40px;
    color: var(--primary-color);
    margin-bottom: 20px;
}

.feature-card h3 {
    font-size: 22px;
    color: var(--text-main);
    margin-bottom: 12px;
}

.feature-card p {
    font-size: 15px;
    color: var(--text-muted);
    line-height: 1.8;
}

/* Pricing Page */
.pricing-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 30px;
}

.pricing-card {
    background: var(--bg-white);
    border-radius: 8px;
    padding: 50px 40px;
    border: 1px solid var(--border-color);
    transition: all 0.3s;
    position: relative;
    overflow: hidden;
}

.pricing-card:hover {
    box-shadow: 0 20px 40px rgba(0,0,0,0.08);
}

.pricing-card.popular {
    border: 2px solid var(--primary-color);
    box-shadow: 0 10px 30px rgba(0, 82, 217, 0.1);
}

.pricing-badge {
    position: absolute;
    top: 20px;
    right: -30px;
    background: var(--primary-color);
    color: white;
    padding: 5px 40px;
    font-size: 12px;
    transform: rotate(45deg);
    font-weight: bold;
}

.pricing-card h3 {
    font-size: 24px;
    color: var(--text-main);
    margin-bottom: 10px;
}

.pricing-card .price {
    font-size: 48px;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 30px;
    padding-bottom: 30px;
    border-bottom: 1px solid var(--border-color);
}

.pricing-card .price span {
    font-size: 16px;
    color: var(--text-muted);
    font-weight: normal;
}

.pricing-card ul {
    margin-bottom: 40px;
}

.pricing-card ul li {
    margin-bottom: 16px;
    font-size: 16px;
    color: var(--text-regular);
    display: flex;
    align-items: center;
}

.pricing-card ul li::before {
    content: "✓";
    color: var(--primary-color);
    font-weight: bold;
    margin-right: 12px;
}

/* News Section */
.news-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
}

.news-card {
    background: var(--bg-white);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    overflow: hidden;
    transition: all 0.3s;
}

.news-card:hover {
    box-shadow: 0 10px 30px rgba(0,0,0,0.08);
}

.news-content {
    padding: 30px;
}

.news-date {
    font-size: 14px;
    color: var(--text-muted);
    margin-bottom: 10px;
    display: block;
}

.news-title {
    font-size: 20px;
    color: var(--text-main);
    margin-bottom: 15px;
    font-weight: 600;
}

.news-desc {
    font-size: 15px;
    color: var(--text-muted);
    margin-bottom: 20px;
}

.news-link {
    color: var(--primary-color);
    font-weight: 500;
    font-size: 15px;
}

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

/* Help Center */
.help-search {
    background: var(--primary-color);
    padding: 80px 24px;
    text-align: center;
    color: white;
}

.help-search h1 {
    font-size: 40px;
    margin-bottom: 20px;
}

.search-box {
    max-width: 600px;
    margin: 0 auto;
    display: flex;
}

.search-box input {
    flex: 1;
    padding: 16px 24px;
    font-size: 16px;
    border: none;
    border-radius: 4px 0 0 4px;
    outline: none;
}

.search-box button {
    padding: 16px 32px;
    background: #003cab;
    color: white;
    border: none;
    border-radius: 0 4px 4px 0;
    font-size: 16px;
    cursor: pointer;
}

.help-categories {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 30px;
    margin-top: -40px;
    padding: 0 24px;
    max-width: 1200px;
    margin-left: auto;
    margin-right: auto;
}

.help-category-card {
    background: white;
    padding: 40px 30px;
    border-radius: 8px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.08);
    text-align: center;
}

.help-category-card h3 {
    margin: 15px 0;
    color: var(--text-main);
}

.faq-list {
    max-width: 800px;
    margin: 60px auto;
}

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

.faq-item h4 {
    font-size: 18px;
    color: var(--text-main);
    margin-bottom: 12px;
}

.faq-item p {
    color: var(--text-muted);
}

/* Footer */
.footer {
    background-color: #1a1a1a;
    color: #999;
    padding: 80px 24px 40px;
}

.footer-content {
    max-width: 1200px;
    margin: 0 auto;
}

.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: 60px;
    margin-bottom: 60px;
    border-bottom: 1px solid #333;
    padding-bottom: 60px;
}

.footer-brand img {
    height: 36px;
    margin-bottom: 20px;
    filter: brightness(0) invert(1);
}

.footer-brand p {
    font-size: 14px;
    line-height: 1.8;
}

.footer-column h4 {
    color: #fff;
    font-size: 16px;
    margin-bottom: 24px;
    font-weight: 500;
}

.footer-column ul li {
    margin-bottom: 12px;
}

.footer-column ul li a {
    color: #999;
    font-size: 14px;
}

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

.footer-bottom {
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 14px;
}

/* Download Page Specific */
.download-hero {
    background: var(--bg-page);
    padding: 120px 24px 80px;
    text-align: center;
}

.download-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 30px;
    margin-top: 60px;
}

.download-card {
    background: white;
    padding: 40px 30px;
    border-radius: 8px;
    border: 1px solid var(--border-color);
    text-align: center;
}

.download-card img {
    height: 64px;
    margin-bottom: 20px;
}

@media (max-width: 768px) {
    .nav-links {
        display: none;
    }
    .hero-enterprise h1 {
        font-size: 36px;
    }
    .footer-grid {
        grid-template-columns: 1fr;
        gap: 40px;
    }
}