:root {
    --primary: #1A73E8; /* 科技蓝 */
    --primary-hover: #1557B0;
    --text-dark: #202124;
    --text-gray: #5F6368;
    --text-light: #9AA0A6;
    --bg-white: #FFFFFF;
    --bg-gray: #F8F9FA;
    --border-color: #E8EAED;
    --shadow-soft: 0 4px 12px rgba(0, 0, 0, 0.03);
}

* { margin: 0; padding: 0; box-sizing: border-box; }
body { 
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    color: var(--text-dark); 
    background-color: var(--bg-white);
    line-height: 1.7;
    font-weight: 300;
}
a { text-decoration: none; color: inherit; transition: 0.3s; }
ul { list-style: none; }
img { max-width: 100%; display: block; border-radius: 4px; }
h1, h2, h3, h4 { font-weight: 400; color: var(--text-dark); }

/* 导航 */
.header { background: var(--bg-white); border-bottom: 1px solid var(--border-color); position: sticky; top: 0; z-index: 1000; }
.nav-container { max-width: 1200px; margin: 0 auto; display: flex; justify-content: space-between; align-items: center; height: 80px; padding: 0 20px; }
.logo { font-size: 20px; font-weight: 500; display: flex; align-items: center; gap: 12px; letter-spacing: 0.5px; }
.logo img { width: 28px; height: 28px; }
.nav-links { display: flex; gap: 40px; }
.nav-links a { font-size: 15px; color: var(--text-gray); transition: 0.2s; }
.nav-links a:hover, .nav-links a.active { color: var(--primary); }

/* 按钮 */
.btn {
    display: inline-flex; align-items: center; justify-content: center;
    padding: 12px 32px; border-radius: 40px; font-weight: 400; font-size: 16px;
    cursor: pointer; transition: 0.3s; border: 1px solid transparent; letter-spacing: 0.5px;
}
.btn-primary { background: var(--primary); color: #fff; box-shadow: 0 2px 6px rgba(26, 115, 232, 0.2); }
.btn-primary:hover { background: var(--primary-hover); box-shadow: 0 4px 10px rgba(26, 115, 232, 0.3); }
.btn-outline { background: var(--bg-white); color: var(--text-dark); border-color: var(--border-color); }
.btn-outline:hover { background: var(--bg-gray); border-color: #DADCE0; }

.container { max-width: 1200px; margin: 0 auto; padding: 0 20px; }
.section { padding: 140px 0; }
.section-alt { background-color: var(--bg-gray); border-top: 1px solid var(--border-color); border-bottom: 1px solid var(--border-color); }
.sec-title { font-size: 40px; text-align: center; margin-bottom: 24px; letter-spacing: -0.5px; }
.sec-desc { font-size: 18px; text-align: center; color: var(--text-gray); margin-bottom: 80px; max-width: 600px; margin-inline: auto; font-weight: 300; }

/* 首屏大留白 */
.hero { padding: 160px 0 100px; text-align: center; }
.hero-content { max-width: 800px; margin: 0 auto; }
.hero-title { font-size: 64px; line-height: 1.1; margin-bottom: 24px; letter-spacing: -1px; }
.hero-subtitle { font-size: 24px; color: var(--primary); margin-bottom: 30px; font-weight: 400; }
.hero-desc { font-size: 18px; color: var(--text-gray); margin-bottom: 48px; max-width: 600px; margin-inline: auto; }
.hero-btns { display: flex; justify-content: center; gap: 24px; margin-bottom: 80px; }
.hero-visual { max-width: 1000px; margin: 0 auto; position: relative; }
.hero-visual img { box-shadow: 0 12px 40px rgba(0,0,0,0.06); border: 1px solid var(--border-color); border-radius: 8px; }

/* 核心卖点细线风 */
.feature-grid { display: grid; grid-template-columns: repeat(5, 1fr); gap: 30px; }
.f-card { text-align: center; padding: 40px 20px; border: 1px solid var(--border-color); border-radius: 8px; background: var(--bg-white); transition: 0.3s; }
.f-card:hover { box-shadow: var(--shadow-soft); border-color: #DADCE0; transform: translateY(-2px); }
.f-card img { width: 40px; height: 40px; margin: 0 auto 24px; opacity: 0.8; }
.f-card h3 { font-size: 16px; margin-bottom: 12px; font-weight: 500; }
.f-card p { font-size: 14px; color: var(--text-gray); }

/* 功能详情 */
.detail-modules { display: flex; flex-direction: column; gap: 120px; }
.detail-row { display: flex; align-items: center; gap: 80px; }
.detail-row:nth-child(even) { flex-direction: row-reverse; }
.d-text { flex: 1; }
.d-text h3 { font-size: 32px; margin-bottom: 24px; letter-spacing: -0.5px; }
.d-text p { font-size: 16px; color: var(--text-gray); margin-bottom: 32px; line-height: 1.8; }
.d-data { display: inline-block; padding: 8px 16px; background: var(--bg-gray); border: 1px solid var(--border-color); border-radius: 20px; font-size: 14px; color: var(--text-dark); }
.d-img { flex: 1.2; }
.d-img img { border: 1px solid var(--border-color); box-shadow: var(--shadow-soft); }

/* 浏览器对比 */
.compare-box { background: var(--bg-white); border: 1px solid var(--border-color); border-radius: 8px; overflow: hidden; }
.compare-table { width: 100%; border-collapse: collapse; text-align: left; }
.compare-table th, .compare-table td { padding: 24px 32px; border-bottom: 1px solid var(--border-color); }
.compare-table th { background: var(--bg-gray); font-size: 13px; color: var(--text-gray); text-transform: uppercase; letter-spacing: 1px; font-weight: 500; }
.compare-table td { font-size: 15px; }
.compare-table .hl { color: var(--primary); font-weight: 500; background: rgba(26, 115, 232, 0.02); }
.compare-table tr:last-child td { border-bottom: none; }

/* 下载版本 */
.v-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 40px; }
.v-card { padding: 60px 40px; text-align: center; border: 1px solid var(--border-color); border-radius: 8px; background: var(--bg-white); transition: 0.3s; }
.v-card:hover { box-shadow: var(--shadow-soft); }
.v-card.rec { border: 1px solid var(--primary); box-shadow: 0 8px 24px rgba(26, 115, 232, 0.08); }
.v-card h3 { font-size: 24px; margin-bottom: 16px; font-weight: 400; }
.v-card p { font-size: 15px; color: var(--text-gray); margin-bottom: 40px; height: 50px; }
.v-card .btn { width: 100%; }

/* 数据展示 */
.data-sec { display: flex; justify-content: center; gap: 100px; padding: 80px 0; border-top: 1px solid var(--border-color); border-bottom: 1px solid var(--border-color); margin: 60px 0; }
.data-item { text-align: center; }
.data-item h4 { font-size: 56px; font-weight: 300; color: var(--primary); margin-bottom: 12px; letter-spacing: -1px; }
.data-item p { font-size: 14px; color: var(--text-gray); letter-spacing: 0.5px; text-transform: uppercase; }

/* FAQ */
.faq-grid { display: flex; flex-direction: column; gap: 16px; max-width: 800px; margin: 0 auto; }
.faq-box { padding: 30px; border: 1px solid var(--border-color); border-radius: 8px; background: var(--bg-white); }
.faq-box h4 { font-size: 16px; margin-bottom: 12px; font-weight: 500; display: flex; align-items: center; gap: 8px; }
.faq-box h4::before { content: ''; display: inline-block; width: 4px; height: 14px; background: var(--primary); }
.faq-box p { font-size: 15px; color: var(--text-gray); line-height: 1.6; }

footer { padding: 60px 0; text-align: center; color: var(--text-light); font-size: 13px; border-top: 1px solid var(--border-color); }