:root {
    --bg-white: #FFFFFF;
    --bg-light: #F9F9FA;
    --text-black: #111111;
    --text-gray: #555555;
    --text-light: #999999;
    --accent: #000000;
    --border: #EEEEEE;
    --space-xl: 160px;
    --space-lg: 100px;
    --space-md: 60px;
}

* { margin: 0; padding: 0; box-sizing: border-box; }
body { font-family: "SF Pro Display", -apple-system, "Helvetica Neue", Helvetica, Arial, sans-serif; background-color: var(--bg-white); color: var(--text-black); line-height: 1.5; font-weight: 400; -webkit-font-smoothing: antialiased; }
a { text-decoration: none; color: inherit; transition: opacity 0.3s ease; }
a:hover { opacity: 0.6; }
img { max-width: 100%; display: block; border-radius: 4px; }

/* 导航 */
.header { position: sticky; top: 0; background: rgba(255,255,255,0.95); backdrop-filter: blur(20px); z-index: 1000; border-bottom: 1px solid var(--border); }
.nav-wrap { max-width: 1400px; margin: 0 auto; display: flex; justify-content: space-between; align-items: center; height: 80px; padding: 0 40px; }
.logo { font-size: 20px; font-weight: 600; letter-spacing: 1px; display: flex; align-items: center; gap: 12px; }
.logo img { width: 32px; height: 32px; border-radius: 0; }
.nav-links { display: flex; gap: 40px; }
.nav-links a { font-size: 14px; font-weight: 500; letter-spacing: 1px; color: var(--text-gray); }
.nav-links a:hover, .nav-links a.active { color: var(--text-black); }

/* 按钮 */
.btn { display: inline-flex; align-items: center; justify-content: center; padding: 18px 40px; font-size: 15px; font-weight: 500; letter-spacing: 2px; cursor: pointer; transition: all 0.4s cubic-bezier(0.16, 1, 0.3, 1); border-radius: 0; }
.btn-primary { background: var(--accent); color: #FFF; border: 1px solid var(--accent); }
.btn-primary:hover { background: #333; opacity: 1; }
.btn-outline { background: transparent; color: var(--accent); border: 1px solid var(--border); }
.btn-outline:hover { border-color: var(--accent); opacity: 1; }

/* 容器与排版留白 */
.container { max-width: 1200px; margin: 0 auto; padding: var(--space-xl) 20px; }
.sec-title { font-size: 40px; font-weight: 300; letter-spacing: 4px; margin-bottom: 20px; text-align: center; }
.sec-subtitle { font-size: 16px; font-weight: 300; color: var(--text-gray); letter-spacing: 2px; text-align: center; margin-bottom: var(--space-lg); text-transform: uppercase; }

/* Hero 区 */
.hero { text-align: center; padding: var(--space-xl) 20px 0; background: #FFF; }
.hero-content { max-width: 800px; margin: 0 auto var(--space-lg); }
.hero h1 { font-size: 72px; font-weight: 400; letter-spacing: 8px; margin-bottom: 24px; }
.hero .subtitle { font-size: 20px; font-weight: 300; color: var(--text-gray); letter-spacing: 4px; margin-bottom: 48px; }
.hero-btns { display: flex; justify-content: center; gap: 20px; }
.hero-visual { max-width: 1200px; margin: 0 auto; position: relative; }
.hero-visual img { box-shadow: 0 40px 80px rgba(0,0,0,0.08); border-radius: 12px; }

/* 核心卖点 */
.feature-grid { display: grid; grid-template-columns: repeat(5, 1fr); gap: 40px; text-align: center; }
.f-box { padding: 0 10px; }
.f-box img { width: 48px; height: 48px; margin: 0 auto 24px; border-radius: 0; filter: grayscale(100%) opacity(0.8); transition: filter 0.3s; }
.f-box:hover img { filter: grayscale(0%) opacity(1); }
.f-box h3 { font-size: 15px; font-weight: 500; letter-spacing: 1px; margin-bottom: 12px; }
.f-box p { font-size: 13px; color: var(--text-gray); line-height: 1.8; font-weight: 300; }

/* 功能详情 - 精致留白排版 */
.detail-sec { padding: var(--space-xl) 0; border-top: 1px solid var(--border); }
.detail-item { display: flex; align-items: center; gap: 120px; margin-bottom: var(--space-xl); }
.detail-item:last-child { margin-bottom: 0; }
.detail-item:nth-child(even) { flex-direction: row-reverse; }
.d-text { flex: 1; }
.d-text h3 { font-size: 32px; font-weight: 300; letter-spacing: 2px; margin-bottom: 24px; }
.d-text p { font-size: 16px; color: var(--text-gray); line-height: 2; margin-bottom: 40px; font-weight: 300; }
.d-data { font-size: 14px; letter-spacing: 2px; font-weight: 500; text-transform: uppercase; color: var(--text-black); border-bottom: 1px solid var(--text-black); display: inline-block; padding-bottom: 8px; }
.d-img { flex: 1; }
.d-img img { border-radius: 8px; box-shadow: 0 20px 40px rgba(0,0,0,0.05); }

/* 数据背书 */
.data-sec { background: var(--bg-light); padding: var(--space-xl) 0; }
.data-inner { max-width: 1200px; margin: 0 auto; display: flex; justify-content: space-around; text-align: center; }
.data-item h4 { font-size: 56px; font-weight: 200; letter-spacing: 2px; margin-bottom: 16px; }
.data-item p { font-size: 14px; font-weight: 400; color: var(--text-gray); letter-spacing: 2px; text-transform: uppercase; }

/* 对比区域 */
.compare-box { margin-top: var(--space-md); }
.compare-table { width: 100%; border-collapse: collapse; text-align: left; }
.compare-table th, .compare-table td { padding: 30px; border-bottom: 1px solid var(--border); }
.compare-table th { font-weight: 500; font-size: 14px; color: var(--text-gray); letter-spacing: 2px; text-transform: uppercase; }
.compare-table td { font-size: 15px; font-weight: 300; }
.compare-table .hl { font-weight: 500; color: var(--text-black); }

/* 下载版本区 */
.dl-wrap { display: grid; grid-template-columns: repeat(3, 1fr); gap: 40px; }
.dl-card { padding: 60px 40px; border: 1px solid var(--border); text-align: center; transition: all 0.4s ease; background: #FFF; }
.dl-card:hover { border-color: var(--text-black); box-shadow: 0 20px 40px rgba(0,0,0,0.04); }
.dl-card h3 { font-size: 20px; font-weight: 400; letter-spacing: 2px; margin-bottom: 20px; }
.dl-card p { font-size: 14px; color: var(--text-gray); font-weight: 300; line-height: 1.8; margin-bottom: 40px; height: 50px; }
.dl-card .btn { width: 100%; }

/* FAQ */
.faq-list { max-width: 800px; margin: 0 auto; }
.faq-item { border-bottom: 1px solid var(--border); padding: 30px 0; }
.faq-item h4 { font-size: 18px; font-weight: 400; letter-spacing: 1px; margin-bottom: 16px; }
.faq-item p { font-size: 15px; color: var(--text-gray); font-weight: 300; line-height: 1.8; }

/* Footer */
.footer { padding: 80px 20px; text-align: center; background: var(--bg-light); border-top: 1px solid var(--border); }
.footer p { font-size: 13px; color: var(--text-light); letter-spacing: 1px; line-height: 2; }