:root {
    --color-primary: #2563EB;
    --color-primary-hover: #1D4ED8;
    --color-text-main: #111827;
    --color-text-muted: #4B5563;
    --color-bg-white: #FFFFFF;
    --color-bg-gray: #F9FAFB;
    --color-border: #E5E7EB;
    
    --space-sm: 16px;
    --space-md: 32px;
    --space-lg: 64px;
    --space-xl: 96px;
    
    --radius-sm: 6px;
    --radius-md: 12px;
}

* { margin: 0; padding: 0; box-sizing: border-box; }
body { 
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    color: var(--color-text-main); 
    background-color: var(--color-bg-white);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
}
a { text-decoration: none; color: inherit; transition: color 0.2s; }
ul { list-style: none; }
img { max-width: 100%; display: block; border-radius: var(--radius-sm); }

/* 架构清晰的导航栏 */
.header {
    background-color: var(--color-bg-white);
    border-bottom: 1px solid var(--color-border);
    position: sticky; top: 0; z-index: 1000;
}
.nav-container {
    max-width: 1200px; margin: 0 auto; padding: 0 24px;
    display: flex; justify-content: space-between; align-items: center; height: 72px;
}
.brand { font-size: 22px; font-weight: 700; color: var(--color-text-main); display: flex; align-items: center; gap: 12px; }
.brand img { width: 32px; height: 32px; }
.nav-menu { display: flex; gap: var(--space-md); }
.nav-menu a { font-size: 16px; font-weight: 500; color: var(--color-text-muted); padding: 8px 0; }
.nav-menu a:hover, .nav-menu a.active { color: var(--color-primary); }

/* 按钮组件 */
.btn {
    display: inline-flex; align-items: center; justify-content: center;
    padding: 12px 28px; border-radius: var(--radius-sm); font-weight: 600; font-size: 16px;
    cursor: pointer; transition: all 0.2s; border: 1px solid transparent;
}
.btn-primary { background-color: var(--color-primary); color: #fff; }
.btn-primary:hover { background-color: var(--color-primary-hover); }
.btn-outline { background-color: transparent; color: var(--color-text-main); border-color: var(--color-border); }
.btn-outline:hover { background-color: var(--color-bg-gray); }

/* 布局容器 */
.layout-container { max-width: 1200px; margin: 0 auto; padding: 0 24px; }
.section { padding: var(--space-xl) 0; }
.section-alt { background-color: var(--color-bg-gray); }

/* 标题规范 */
.section-header { text-align: center; margin-bottom: var(--space-lg); }
.section-title { font-size: 36px; font-weight: 700; margin-bottom: var(--space-sm); color: var(--color-text-main); letter-spacing: -0.02em; }
.section-desc { font-size: 18px; color: var(--color-text-muted); max-width: 600px; margin: 0 auto; }

/* 首屏 Hero 区 */
.hero { padding: 120px 0; border-bottom: 1px solid var(--color-border); }
.hero-grid { display: grid; grid-template-columns: 1fr 1fr; gap: var(--space-lg); align-items: center; }
.hero-content h1 { font-size: 56px; font-weight: 800; line-height: 1.1; margin-bottom: 24px; letter-spacing: -0.03em; }
.hero-content .subtitle { font-size: 24px; color: var(--color-text-muted); font-weight: 500; margin-bottom: 24px; }
.hero-content p { font-size: 18px; color: var(--color-text-muted); margin-bottom: 40px; }
.hero-actions { display: flex; gap: var(--space-sm); }
.hero-visual img { box-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04); border: 1px solid var(--color-border); }

/* 核心卖点区 */
.features-grid { display: grid; grid-template-columns: repeat(5, 1fr); gap: var(--space-md); }
.feature-card { text-align: center; }
.feature-card img { width: 56px; height: 56px; margin: 0 auto var(--space-sm); }
.feature-card h3 { font-size: 18px; font-weight: 600; margin-bottom: 8px; }
.feature-card p { font-size: 14px; color: var(--color-text-muted); }

/* 功能详情区 (图文交替) */
.details-module { display: flex; flex-direction: column; gap: var(--space-xl); }
.detail-row { display: grid; grid-template-columns: 1fr 1fr; gap: var(--space-lg); align-items: center; }
.detail-row:nth-child(even) .detail-content { order: 2; }
.detail-content h3 { font-size: 32px; font-weight: 700; margin-bottom: var(--space-sm); }
.detail-content p { font-size: 18px; color: var(--color-text-muted); margin-bottom: var(--space-md); }
.data-badge { display: inline-block; background-color: #E0E7FF; color: #3730A3; padding: 6px 16px; border-radius: 20px; font-weight: 600; font-size: 14px; }
.detail-image img { box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.1); border: 1px solid var(--color-border); }

/* 浏览器对比区 */
.comparison-table-wrapper { overflow-x: auto; border: 1px solid var(--color-border); border-radius: var(--radius-md); background: var(--color-bg-white); }
.comparison-table { width: 100%; border-collapse: collapse; text-align: left; }
.comparison-table th, .comparison-table td { padding: 24px; border-bottom: 1px solid var(--color-border); }
.comparison-table th { background-color: var(--color-bg-gray); font-weight: 600; font-size: 14px; text-transform: uppercase; letter-spacing: 0.05em; color: var(--color-text-muted); }
.comparison-table td { font-size: 16px; }
.comparison-table .highlight { background-color: #F0FDF4; color: #166534; font-weight: 600; }

/* 下载版本区 */
.download-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: var(--space-md); }
.download-card { background: var(--color-bg-white); border: 1px solid var(--color-border); padding: 48px 32px; border-radius: var(--radius-md); text-align: center; display: flex; flex-direction: column; }
.download-card h3 { font-size: 24px; font-weight: 700; margin-bottom: var(--space-sm); }
.download-card p { font-size: 16px; color: var(--color-text-muted); margin-bottom: var(--space-md); flex-grow: 1; }
.download-card .btn { width: 100%; }

/* 数据背书区 */
.metrics-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: var(--space-md); border-top: 1px solid var(--color-border); border-bottom: 1px solid var(--color-border); padding: var(--space-lg) 0; }
.metric-item { text-align: center; border-right: 1px solid var(--color-border); }
.metric-item:last-child { border-right: none; }
.metric-item h4 { font-size: 48px; font-weight: 800; color: var(--color-primary); margin-bottom: 8px; }
.metric-item p { font-size: 18px; font-weight: 500; color: var(--color-text-muted); }

/* FAQ 区 */
.faq-list { max-width: 800px; margin: 0 auto; display: flex; flex-direction: column; gap: var(--space-md); }
.faq-item { border: 1px solid var(--color-border); border-radius: var(--radius-sm); padding: 24px; background: var(--color-bg-white); }
.faq-item h4 { font-size: 18px; font-weight: 600; margin-bottom: 12px; }
.faq-item p { font-size: 16px; color: var(--color-text-muted); }

/* 页脚 */
.footer { border-top: 1px solid var(--color-border); padding: 40px 0; text-align: center; color: var(--color-text-muted); font-size: 14px; background: var(--color-bg-white); }